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Author SHA1 Message Date
Muchun Song 10a6de19ca seq_file: fix passing wrong private data 
DEFINE_PROC_SHOW_ATTRIBUTE() is supposed to be used to define a series
of functions and variables to register proc file easily. And the users
can use proc_create_data() to pass their own private data and get it
via seq->private in the callback. Unfortunately, the proc file system
use PDE_DATA() to get private data instead of inode->i_private. So fix
it. Fortunately, there only one user of it which does not pass any
private data, so this bug does not break any in-tree codes.

Link: https://lkml.kernel.org/r/20211029032638.84884-1-songmuchun@bytedance.com
Fixes: 97a32539b9 ("proc: convert everything to "struct proc_ops"")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Florent Revest <revest@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:52 -08:00
Andy Shevchenko 372904c080 seq_file: move seq_escape() to a header 
Move seq_escape() to the header as inliner, for a small kernel text size
reduction.

Link: https://lkml.kernel.org/r/20211001122917.67228-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:52 -08:00
Ye Guojin f26663684e signal: remove duplicate include in signal.h 
'linux/string.h' included in 'signal.h' is duplicated.
it's also included at line 7.

Link: https://lkml.kernel.org/r/20211019024934.973008-1-ye.guojin@zte.com.cn
Signed-off-by: Ye Guojin <ye.guojin@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:52 -08:00
Ye Guojin a10677a028 crash_dump: remove duplicate include in crash_dump.h 
In crash_dump.h, header file <linux/pgtable.h> is included twice.  This
duplication was introduced in commit 65fddcfca8ad("mm: reorder includes
after introduction of linux/pgtable.h") where the order of the header
files is adjusted, while the old one was not removed.

Clean it up here.

Link: https://lkml.kernel.org/r/20211020090659.1038877-1-ye.guojin@zte.com.cn
Signed-off-by: Ye Guojin <ye.guojin@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Changcheng Deng <deng.changcheng@zte.com.cn>
Cc: Simon Horman <horms@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:52 -08:00
Changcheng Deng 5605f41917 crash_dump: fix boolreturn.cocci warning 
./include/linux/crash_dump.h: 119: 50-51: WARNING: return of 0/1 in
function 'is_kdump_kernel' with return type bool

Return statements in functions returning bool should use true/false
instead of 1/0.

Link: https://lkml.kernel.org/r/20211020083905.1037952-1-deng.changcheng@zte.com.cn
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ye Guojin <ye.guojin@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:52 -08:00
Kefeng Wang 8f6e42e833 sections: provide internal __is_kernel() and __is_kernel_text() helper 
An internal __is_kernel() helper which only check the kernel address
ranges, and an internal __is_kernel_text() helper which only check text
section ranges.

Link: https://lkml.kernel.org/r/20210930071143.63410-7-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:51 -08:00
Kefeng Wang b9ad8fe7b8 sections: move is_kernel_inittext() into sections.h 
The is_kernel_inittext() and init_kernel_text() are with same
functionality, let's just keep is_kernel_inittext() and move it into
sections.h, then update all the callers.

Link: https://lkml.kernel.org/r/20210930071143.63410-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:50 -08:00
Kefeng Wang a20deb3a34 sections: move and rename core_kernel_data() to is_kernel_core_data() 
Move core_kernel_data() into sections.h and rename it to
is_kernel_core_data(), also make it return bool value, then update all the
callers.

Link: https://lkml.kernel.org/r/20210930071143.63410-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:50 -08:00
Kefeng Wang e7d5c4b0eb kallsyms: fix address-checks for kernel related range 
The is_kernel_inittext/is_kernel_text/is_kernel function should not
include the end address(the labels _einittext, _etext and _end) when check
the address range, the issue exists since Linux v2.6.12.

Link: https://lkml.kernel.org/r/20210930071143.63410-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:50 -08:00
Kefeng Wang 1b1ad288b8 kallsyms: remove arch specific text and data check 
Patch series "sections: Unify kernel sections range check and use", v4.

There are three head files(kallsyms.h, kernel.h and sections.h) which
include the kernel sections range check, let's make some cleanup and unify
them.

1. cleanup arch specific text/data check and fix address boundary check
   in kallsyms.h

2. make all the basic/core kernel range check function into sections.h

3. update all the callers, and use the helper in sections.h to simplify
   the code

After this series, we have 5 APIs about kernel sections range check in
sections.h

 * is_kernel_rodata()		--- already in sections.h
 * is_kernel_core_data()	--- come from core_kernel_data() in kernel.h
 * is_kernel_inittext()		--- come from kernel.h and kallsyms.h
 * __is_kernel_text()		--- add new internal helper
 * __is_kernel()		--- add new internal helper

Note: For the last two helpers, people should not use directly, consider to
      use corresponding function in kallsyms.h.

This patch (of 11):

Remove arch specific text and data check after commit 4ba66a9760 ("arch:
remove blackfin port"), no need arch-specific text/data check.

Link: https://lkml.kernel.org/r/20210930071143.63410-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20210930071143.63410-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:50 -08:00
Lucas De Marchi bfb3ba3206 include/linux/string_helpers.h: add linux/string.h for strlen() 
linux/string_helpers.h uses strlen(), so include the correponding header.
Otherwise we get a compilation error if it's not also included by whoever
included the helper.

Link: https://lkml.kernel.org/r/20211005212634.3223113-1-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:50 -08:00
Imran Khan 0f68d45ef4 lib, stackdepot: add helper to print stack entries into buffer 
To print stack entries into a buffer, users of stackdepot, first get a
list of stack entries using stack_depot_fetch and then print this list
into a buffer using stack_trace_snprint.  Provide a helper in stackdepot
for this purpose.  Also change above mentioned users to use this helper.

[imran.f.khan@oracle.com: fix build error]
  Link: https://lkml.kernel.org/r/20210915175321.3472770-4-imran.f.khan@oracle.com
[imran.f.khan@oracle.com: export stack_depot_snprint() to modules]
  Link: https://lkml.kernel.org/r/20210916133535.3592491-4-imran.f.khan@oracle.com

Link: https://lkml.kernel.org/r/20210915014806.3206938-4-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jani Nikula <jani.nikula@intel.com>	[i915]
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:50 -08:00
Imran Khan 505be48165 lib, stackdepot: add helper to print stack entries 
To print a stack entries, users of stackdepot, first use stack_depot_fetch
to get a list of stack entries and then use stack_trace_print to print
this list.  Provide a helper in stackdepot to print stack entries based on
stackdepot handle.  Also change above mentioned users to use this helper.

Link: https://lkml.kernel.org/r/20210915014806.3206938-3-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:50 -08:00
Rasmus Villemoes e1edc277e6 linux/container_of.h: switch to static_assert 
_Static_assert() is evaluated already in the compiler's frontend, and
gives a somehat more to-the-point error, compared to the BUILD_BUG_ON
macro, which only fires after the optimizer has had a chance to
eliminate calls to functions marked with __attribute__((error)).  In
theory, this might make builds a tiny bit faster.

There's also a little less gunk in the error message emitted:

  lib/sort.c: In function `foo':
  include/linux/build_bug.h:78:41: error: static assertion failed: "pointer type mismatch in container_of()"
     78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)

compared to

  lib/sort.c: In function `foo':
  include/linux/compiler_types.h:322:38: error: call to `__compiletime_assert_2' declared with attribute error: pointer type mismatch in container_of()
    322 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

While at it, fix the copy-pasto in container_of_safe().

Link: https://lkml.kernel.org/r/20211015090530.2774079-1-linux@rasmusvillemoes.dk
Link: https://lore.kernel.org/lkml/20211014132331.GA4811@kernel.org/T/
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Stephen Rothwell e52340de11 kernel.h: split out instruction pointer accessors 
bottom_half.h needs _THIS_IP_ to be standalone, so split that and
_RET_IP_ out from kernel.h into the new instruction_pointer.h.  kernel.h
directly needs them, so include it there and replace the include of
kernel.h with this new file in bottom_half.h.

Link: https://lkml.kernel.org/r/20211028161248.45232-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko b4b8765110 include/linux/generic-radix-tree.h: replace kernel.h with the necessary inclusions 
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

[akpm@linux-foundation.org: include math.h for round_up()]

Link: https://lkml.kernel.org/r/20211027150548.80042-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko 98e1385ef2 include/linux/radix-tree.h: replace kernel.h with the necessary inclusions 
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

Link: https://lkml.kernel.org/r/20211027150528.80003-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko 1fcbd5deac include/linux/sbitmap.h: replace kernel.h with the necessary inclusions 
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

Link: https://lkml.kernel.org/r/20211027150437.79921-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko 5f6286a608 include/linux/delay.h: replace kernel.h with the necessary inclusions 
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

[akpm@linux-foundation.org: cxd2880_common.h needs bits.h for GENMASK()]
[andriy.shevchenko@linux.intel.com: delay.h: fix for removed kernel.h]
  Link: https://lkml.kernel.org/r/20211028170143.56523-1-andriy.shevchenko@linux.intel.com
[akpm@linux-foundation.org: include/linux/fwnode.h needs bits.h for BIT()]

Link: https://lkml.kernel.org/r/20211027150324.79827-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko c540f95959 include/linux/plist.h: replace kernel.h with the necessary inclusions 
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

Link: https://lkml.kernel.org/r/20211013170417.87909-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko 50b09d6145 include/linux/llist.h: replace kernel.h with the necessary inclusions 
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

Link: https://lkml.kernel.org/r/20211013170417.87909-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko cd7187e112 include/linux/list.h: replace kernel.h with the necessary inclusions 
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.

Link: https://lkml.kernel.org/r/20211013170417.87909-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko d2a8ebbf81 kernel.h: split out container_of() and typeof_member() macros 
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt cleaning it up by splitting out container_of() and
typeof_member() macros.

For time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

Note, there are _a lot_ of headers and modules that include kernel.h
solely for one of these macros and this allows to unburden compiler for
the twisted inclusion paths and to make new code cleaner in the future.

Link: https://lkml.kernel.org/r/20211013170417.87909-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
Andy Shevchenko f5d8061484 kernel.h: drop unneeded <linux/kernel.h> inclusion from other headers 
Patch series "kernel.h further split", v5.

kernel.h is a set of something which is not related to each other and
often used in non-crossed compilation units, especially when drivers
need only one or two macro definitions from it.

This patch (of 7):

There is no evidence we need kernel.h inclusion in certain headers.
Drop unneeded <linux/kernel.h> inclusion from other headers.

[sfr@canb.auug.org.au: bottom_half.h needs kernel]
  Link: https://lkml.kernel.org/r/20211015202908.1c417ae2@canb.auug.org.au

Link: https://lkml.kernel.org/r/20211013170417.87909-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20211013170417.87909-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:49 -08:00
David Hildenbrand cc5f2704c9 proc/vmcore: convert oldmem_pfn_is_ram callback to more generic vmcore callbacks 
Let's support multiple registered callbacks, making sure that
registering vmcore callbacks cannot fail.  Make the callback return a
bool instead of an int, handling how to deal with errors internally.
Drop unused HAVE_OLDMEM_PFN_IS_RAM.

We soon want to make use of this infrastructure from other drivers:
virtio-mem, registering one callback for each virtio-mem device, to
prevent reading unplugged virtio-mem memory.

Handle it via a generic vmcore_cb structure, prepared for future
extensions: for example, once we support virtio-mem on s390x where the
vmcore is completely constructed in the second kernel, we want to detect
and add plugged virtio-mem memory ranges to the vmcore in order for them
to get dumped properly.

Handle corner cases that are unexpected and shouldn't happen in sane
setups: registering a callback after the vmcore has already been opened
(warn only) and unregistering a callback after the vmcore has already been
opened (warn and essentially read only zeroes from that point on).

Link: https://lkml.kernel.org/r/20211005121430.30136-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:48 -08:00
zhangyiru 83c1fd763b mm,hugetlb: remove mlock ulimit for SHM_HUGETLB 
Commit 21a3c273f8 ("mm, hugetlb: add thread name and pid to
SHM_HUGETLB mlock rlimit warning") marked this as deprecated in 2012,
but it is not deleted yet.

Mike says he still sees that message in log files on occasion, so maybe we
should preserve this warning.

Also remove hugetlbfs related user_shm_unlock in ipc/shm.c and remove the
user_shm_unlock after out.

Link: https://lkml.kernel.org/r/20211103105857.25041-1-zhangyiru3@huawei.com
Signed-off-by: zhangyiru <zhangyiru3@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liu Zixian <liuzixian4@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: wuxu.wu <wuxu.wu@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:48 -08:00
Johannes Weiner 51b8c1fe25 vfs: keep inodes with page cache off the inode shrinker LRU 
Historically (pre-2.5), the inode shrinker used to reclaim only empty
inodes and skip over those that still contained page cache.  This caused
problems on highmem hosts: struct inode could put fill lowmem zones
before the cache was getting reclaimed in the highmem zones.

To address this, the inode shrinker started to strip page cache to
facilitate reclaiming lowmem.  However, this comes with its own set of
problems: the shrinkers may drop actively used page cache just because
the inodes are not currently open or dirty - think working with a large
git tree.  It further doesn't respect cgroup memory protection settings
and can cause priority inversions between containers.

Nowadays, the page cache also holds non-resident info for evicted cache
pages in order to detect refaults.  We've come to rely heavily on this
data inside reclaim for protecting the cache workingset and driving swap
behavior.  We also use it to quantify and report workload health through
psi.  The latter in turn is used for fleet health monitoring, as well as
driving automated memory sizing of workloads and containers, proactive
reclaim and memory offloading schemes.

The consequences of dropping page cache prematurely is that we're seeing
subtle and not-so-subtle failures in all of the above-mentioned
scenarios, with the workload generally entering unexpected thrashing
states while losing the ability to reliably detect it.

To fix this on non-highmem systems at least, going back to rotating
inodes on the LRU isn't feasible.  We've tried (commit a76cf1a474
("mm: don't reclaim inodes with many attached pages")) and failed
(commit 69056ee6a8 ("Revert "mm: don't reclaim inodes with many
attached pages"")).

The issue is mostly that shrinker pools attract pressure based on their
size, and when objects get skipped the shrinkers remember this as
deferred reclaim work.  This accumulates excessive pressure on the
remaining inodes, and we can quickly eat into heavily used ones, or
dirty ones that require IO to reclaim, when there potentially is plenty
of cold, clean cache around still.

Instead, this patch keeps populated inodes off the inode LRU in the
first place - just like an open file or dirty state would.  An otherwise
clean and unused inode then gets queued when the last cache entry
disappears.  This solves the problem without reintroducing the reclaim
issues, and generally is a bit more scalable than having to wade through
potentially hundreds of thousands of busy inodes.

Locking is a bit tricky because the locks protecting the inode state
(i_lock) and the inode LRU (lru_list.lock) don't nest inside the
irq-safe page cache lock (i_pages.xa_lock).  Page cache deletions are
serialized through i_lock, taken before the i_pages lock, to make sure
depopulated inodes are queued reliably.  Additions may race with
deletions, but we'll check again in the shrinker.  If additions race
with the shrinker itself, we're protected by the i_lock: if find_inode()
or iput() win, the shrinker will bail on the elevated i_count or
I_REFERENCED; if the shrinker wins and goes ahead with the inode, it
will set I_FREEING and inhibit further igets(), which will cause the
other side to create a new instance of the inode instead.

Link: https://lkml.kernel.org/r/20210614211904.14420-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-09 10:02:48 -08:00
Changbin Du 658f9ae761 mm/damon: remove return value from before_terminate callback 
Since the return value of 'before_terminate' callback is never used, we
make it have no return value.

Link: https://lkml.kernel.org/r/20211029005023.8895-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:46 -07:00
Changbin Du 0f91d13366 mm/damon: simplify stop mechanism 
A kernel thread can exit gracefully with kthread_stop().  So we don't
need a new flag 'kdamond_stop'.  And to make sure the task struct is not
freed when accessing it, get reference to it before termination.

Link: https://lkml.kernel.org/r/20211027130517.4404-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:46 -07:00
Xin Hao b5ca3e83dd mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on 
When the ctx->adaptive_targets list is empty, I did some test on
monitor_on interface like this.

    # cat /sys/kernel/debug/damon/target_ids
    #
    # echo on > /sys/kernel/debug/damon/monitor_on
    # damon: kdamond (5390) starts

Though the ctx->adaptive_targets list is empty, but the kthread_run
still be called, and the kdamond.x thread still be created, this is
meaningless.

So there adds a judgment in 'dbgfs_monitor_on_write', if the
ctx->adaptive_targets list is empty, return -EINVAL.

Link: https://lkml.kernel.org/r/0a60a6e8ec9d71989e0848a4dc3311996ca3b5d4.1634720326.git.xhao@linux.alibaba.com
Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:46 -07:00
SeongJae Park ee801b7dd7 mm/damon/schemes: activate schemes based on a watermarks mechanism 
DAMON-based operation schemes need to be manually turned on and off.  In
some use cases, however, the condition for turning a scheme on and off
would depend on the system's situation.  For example, schemes for
proactive pages reclamation would need to be turned on when some memory
pressure is detected, and turned off when the system has enough free
memory.

For easier control of schemes activation based on the system situation,
this introduces a watermarks-based mechanism.  The client can describe
the watermark metric (e.g., amount of free memory in the system),
watermark check interval, and three watermarks, namely high, mid, and
low.  If the scheme is deactivated, it only gets the metric and compare
that to the three watermarks for every check interval.  If the metric is
higher than the high watermark, the scheme is deactivated.  If the
metric is between the mid watermark and the low watermark, the scheme is
activated.  If the metric is lower than the low watermark, the scheme is
deactivated again.  This is to allow users fall back to traditional
page-granularity mechanisms.

Link: https://lkml.kernel.org/r/20211019150731.16699-12-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park 198f0f4c58 mm/damon/vaddr,paddr: support pageout prioritization 
This makes the default monitoring primitives for virtual address spaces
and the physical address sapce to support memory regions prioritization
for 'PAGEOUT' DAMOS action.  It calculates hotness of each region as
weighted sum of 'nr_accesses' and 'age' of the region and get the
priority score as reverse of the hotness, so that cold regions can be
paged out first.

Link: https://lkml.kernel.org/r/20211019150731.16699-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park 38683e0031 mm/damon/schemes: prioritize regions within the quotas 
This makes DAMON apply schemes to regions having higher priority first,
if it cannot apply schemes to all regions due to the quotas.

The prioritization function should be implemented in the monitoring
primitives.  Those would commonly calculate the priority of the region
using attributes of regions, namely 'size', 'nr_accesses', and 'age'.
For example, some primitive would calculate the priority of each region
using a weighted sum of 'nr_accesses' and 'age' of the region.

The optimal weights would depend on give environments, so this makes
those customizable.  Nevertheless, the score calculation functions are
only encouraged to respect the weights, not mandated.

Link: https://lkml.kernel.org/r/20211019150731.16699-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park 1cd2430300 mm/damon/schemes: implement time quota 
The size quota feature of DAMOS is useful for IO resource-critical
systems, but not so intuitive for CPU time-critical systems.  Systems
using zram or zswap-like swap device would be examples.

To provide another intuitive ways for such systems, this implements
time-based quota for DAMON-based Operation Schemes.  If the quota is
set, DAMOS tries to use only up to the user-defined quota of CPU time
within a given time window.

Link: https://lkml.kernel.org/r/20211019150731.16699-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park 50585192bc mm/damon/schemes: skip already charged targets and regions 
If DAMOS has stopped applying action in the middle of a group of memory
regions due to its size quota, it starts the work again from the
beginning of the address space in the next charge window.  If there is a
huge memory region at the beginning of the address space and it fulfills
the scheme's target data access pattern always, the action will applied
to only the region.

This mitigates the case by skipping memory regions that charged in
current charge window at the beginning of next charge window.

Link: https://lkml.kernel.org/r/20211019150731.16699-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park 2b8a248d58 mm/damon/schemes: implement size quota for schemes application speed control 
There could be arbitrarily large memory regions fulfilling the target
data access pattern of a DAMON-based operation scheme.  In the case,
applying the action of the scheme could incur too high overhead.  To
provide an intuitive way for avoiding it, this implements a feature
called size quota.  If the quota is set, DAMON tries to apply the action
only up to the given amount of memory regions within a given time
window.

Link: https://lkml.kernel.org/r/20211019150731.16699-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park 57223ac295 mm/damon/paddr: support the pageout scheme 
Introduction
============

This patchset 1) makes the engine for general data access
pattern-oriented memory management (DAMOS) be more useful for production
environments, and 2) implements a static kernel module for lightweight
proactive reclamation using the engine.

Proactive Reclamation
---------------------

On general memory over-committed systems, proactively reclaiming cold
pages helps saving memory and reducing latency spikes that incurred by
the direct reclaim or the CPU consumption of kswapd, while incurring
only minimal performance degradation[2].

A Free Pages Reporting[8] based memory over-commit virtualization system
would be one more specific use case.  In the system, the guest VMs
reports their free memory to host, and the host reallocates the reported
memory to other guests.  As a result, the system's memory utilization
can be maximized.  However, the guests could be not so memory-frugal,
because some kernel subsystems and user-space applications are designed
to use as much memory as available.  Then, guests would report only
small amount of free memory to host, results in poor memory utilization.
Running the proactive reclamation in such guests could help mitigating
this problem.

Google has also implemented this idea and using it in their data center.
They further proposed upstreaming it in LSFMM'19, and "the general
consensus was that, while this sort of proactive reclaim would be useful
for a number of users, the cost of this particular solution was too high
to consider merging it upstream"[3].  The cost mainly comes from the
coldness tracking.  Roughly speaking, the implementation periodically
scans the 'Accessed' bit of each page.  For the reason, the overhead
linearly increases as the size of the memory and the scanning frequency
grows.  As a result, Google is known to dedicating one CPU for the work.
That's a reasonable option to someone like Google, but it wouldn't be so
to some others.

DAMON and DAMOS: An engine for data access pattern-oriented memory management
-----------------------------------------------------------------------------

DAMON[4] is a framework for general data access monitoring.  Its
adaptive monitoring overhead control feature minimizes its monitoring
overhead.  It also let the upper-bound of the overhead be configurable
by clients, regardless of the size of the monitoring target memory.
While monitoring 70 GiB memory of a production system every 5
milliseconds, it consumes less than 1% single CPU time.  For this, it
could sacrify some of the quality of the monitoring results.
Nevertheless, the lower-bound of the quality is configurable, and it
uses a best-effort algorithm for better quality.  Our test results[5]
show the quality is practical enough.  From the production system
monitoring, we were able to find a 4 KiB region in the 70 GiB memory
that shows highest access frequency.

We normally don't monitor the data access pattern just for fun but to
improve something like memory management.  Proactive reclamation is one
such usage.  For such general cases, DAMON provides a feature called
DAMon-based Operation Schemes (DAMOS)[6].  It makes DAMON an engine for
general data access pattern oriented memory management.  Using this,
clients can ask DAMON to find memory regions of specific data access
pattern and apply some memory management action (e.g., page out, move to
head of the LRU list, use huge page, ...).  We call the request
'scheme'.

Proactive Reclamation on top of DAMON/DAMOS
-------------------------------------------

Therefore, by using DAMON for the cold pages detection, the proactive
reclamation's monitoring overhead issue can be solved.  Actually, we
previously implemented a version of proactive reclamation using DAMOS
and achieved noticeable improvements with our evaluation setup[5].
Nevertheless, it more for a proof-of-concept, rather than production
uses.  It supports only virtual address spaces of processes, and require
additional tuning efforts for given workloads and the hardware.  For the
tuning, we introduced a simple auto-tuning user space tool[8].  Google
is also known to using a ML-based similar approach for their fleets[2].
But, making it just works with intuitive knobs in the kernel would be
helpful for general users.

To this end, this patchset improves DAMOS to be ready for such
production usages, and implements another version of the proactive
reclamation, namely DAMON_RECLAIM, on top of it.

DAMOS Improvements: Aggressiveness Control, Prioritization, and Watermarks
--------------------------------------------------------------------------

First of all, the current version of DAMOS supports only virtual address
spaces.  This patchset makes it supports the physical address space for
the page out action.

Next major problem of the current version of DAMOS is the lack of the
aggressiveness control, which can results in arbitrary overhead.  For
example, if huge memory regions having the data access pattern of
interest are found, applying the requested action to all of the regions
could incur significant overhead.  It can be controlled by tuning the
target data access pattern with manual or automated approaches[2,7].
But, some people would prefer the kernel to just work with only
intuitive tuning or default values.

For such cases, this patchset implements a safeguard, namely time/size
quota.  Using this, the clients can specify up to how much time can be
used for applying the action, and/or up to how much memory regions the
action can be applied within a user-specified time duration.  A followup
question is, to which memory regions should the action applied within
the limits? We implement a simple regions prioritization mechanism for
each action and make DAMOS to apply the action to high priority regions
first.  It also allows clients tune the prioritization mechanism to use
different weights for size, access frequency, and age of memory regions.
This means we could use not only LRU but also LFU or some fancy
algorithms like CAR[9] with lightweight overhead.

Though DAMON is lightweight, someone would want to remove even the cold
pages monitoring overhead when it is unnecessary.  Currently, it should
manually turned on and off by clients, but some clients would simply
want to turn it on and off based on some metrics like free memory ratio
or memory fragmentation.  For such cases, this patchset implements a
watermarks-based automatic activation feature.  It allows the clients
configure the metric of their interest, and three watermarks of the
metric.  If the metric is higher than the high watermark or lower than
the low watermark, the scheme is deactivated.  If the metric is lower
than the mid watermark but higher than the low watermark, the scheme is
activated.

DAMON-based Reclaim
-------------------

Using the improved version of DAMOS, this patchset implements a static
kernel module called 'damon_reclaim'.  It finds memory regions that
didn't accessed for specific time duration and page out.  Consuming too
much CPU for the paging out operations, or doing pageout too frequently
can be critical for systems configuring their swap devices with
software-defined in-memory block devices like zram/zswap or total number
of writes limited devices like SSDs, respectively.  To avoid the
problems, the time/size quotas can be configured.  Under the quotas, it
pages out memory regions that didn't accessed longer first.  Also, to
remove the monitoring overhead under peaceful situation, and to fall
back to the LRU-list based page granularity reclamation when it doesn't
make progress, the three watermarks based activation mechanism is used,
with the free memory ratio as the watermark metric.

For convenient configurations, it provides several module parameters.
Using these, sysadmins can enable/disable it, and tune its parameters
including the coldness identification time threshold, the time/size
quotas and the three watermarks.

Evaluation
==========

In short, DAMON_RECLAIM with 50ms/s time quota and regions
prioritization on v5.15-rc5 Linux kernel with ZRAM swap device achieves
38.58% memory saving with only 1.94% runtime overhead.  For this,
DAMON_RECLAIM consumes only 4.97% of single CPU time.

Setup
-----

We evaluate DAMON_RECLAIM to show how each of the DAMOS improvements
make effect.  For this, we measure DAMON_RECLAIM's CPU consumption,
entire system memory footprint, total number of major page faults, and
runtime of 24 realistic workloads in PARSEC3 and SPLASH-2X benchmark
suites on my QEMU/KVM based virtual machine.  The virtual machine runs
on an i3.metal AWS instance, has 130GiB memory, and runs a linux kernel
built on latest -mm tree[1] plus this patchset.  It also utilizes a 4
GiB ZRAM swap device.  We repeats the measurement 5 times and use
averages.

[1] https://github.com/hnaz/linux-mm/tree/v5.15-rc5-mmots-2021-10-13-19-55

Detailed Results
----------------

The results are summarized in the below table.

With coldness identification threshold of 5 seconds, DAMON_RECLAIM
without the time quota-based speed limit achieves 47.21% memory saving,
but incur 4.59% runtime slowdown to the workloads on average.  For this,
DAMON_RECLAIM consumes about 11.28% single CPU time.

Applying time quotas of 200ms/s, 50ms/s, and 10ms/s without the regions
prioritization reduces the slowdown to 4.89%, 2.65%, and 1.5%,
respectively.  Time quota of 200ms/s (20%) makes no real change compared
to the quota unapplied version, because the quota unapplied version
consumes only 11.28% CPU time.  DAMON_RECLAIM's CPU utilization also
similarly reduced: 11.24%, 5.51%, and 2.01% of single CPU time.  That
is, the overhead is proportional to the speed limit.  Nevertheless, it
also reduces the memory saving because it becomes less aggressive.  In
detail, the three variants show 48.76%, 37.83%, and 7.85% memory saving,
respectively.

Applying the regions prioritization (page out regions that not accessed
longer first within the time quota) further reduces the performance
degradation.  Runtime slowdowns and total number of major page faults
increase has been 4.89%/218,690% -> 4.39%/166,136% (200ms/s),
2.65%/111,886% -> 1.94%/59,053% (50ms/s), and 1.5%/34,973.40% ->
2.08%/8,781.75% (10ms/s).  The runtime under 10ms/s time quota has
increased with prioritization, but apparently that's under the margin of
error.

    time quota   prioritization  memory_saving  cpu_util  slowdown  pgmajfaults overhead
    N            N               47.21%         11.28%    4.59%     194,802%
    200ms/s      N               48.76%         11.24%    4.89%     218,690%
    50ms/s       N               37.83%         5.51%     2.65%     111,886%
    10ms/s       N               7.85%          2.01%     1.5%      34,793.40%
    200ms/s      Y               50.08%         10.38%    4.39%     166,136%
    50ms/s       Y               38.58%         4.97%     1.94%     59,053%
    10ms/s       Y               3.63%          1.73%     2.08%     8,781.75%

Baseline and Complete Git Trees
===============================

The patches are based on the latest -mm tree
(v5.15-rc5-mmots-2021-10-13-19-55).  You can also clone the complete git tree
from:

    $ git clone git://github.com/sjp38/linux -b damon_reclaim/patches/v1

The web is also available:
https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git/tag/?h=damon_reclaim/patches/v1

Sequence Of Patches
===================

The first patch makes DAMOS support the physical address space for the
page out action.  Following five patches (patches 2-6) implement the
time/size quotas.  Next four patches (patches 7-10) implement the memory
regions prioritization within the limit.  Then, three following patches
(patches 11-13) implement the watermarks-based schemes activation.

Finally, the last two patches (patches 14-15) implement and document the
DAMON-based reclamation using the advanced DAMOS.

[1] https://www.kernel.org/doc/html/v5.15-rc1/vm/damon/index.html
[2] https://research.google/pubs/pub48551/
[3] https://lwn.net/Articles/787611/
[4] https://damonitor.github.io
[5] https://damonitor.github.io/doc/html/latest/vm/damon/eval.html
[6] https://lore.kernel.org/linux-mm/20211001125604.29660-1-sj@kernel.org/
[7] https://github.com/awslabs/damoos
[8] https://www.kernel.org/doc/html/latest/vm/free_page_reporting.html
[9] https://www.usenix.org/conference/fast-04/car-clock-adaptive-replacement

This patch (of 15):

This makes the DAMON primitives for physical address space support the
pageout action for DAMON-based Operation Schemes.  With this commit,
hence, users can easily implement system-level data access-aware
reclamations using DAMOS.

[sj@kernel.org: fix missing-prototype build warning]
  Link: https://lkml.kernel.org/r/20211025064220.13904-1-sj@kernel.org

Link: https://lkml.kernel.org/r/20211019150731.16699-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211019150731.16699-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park a28397beb5 mm/damon: implement primitives for physical address space monitoring 
This implements the monitoring primitives for the physical memory
address space.  Internally, it uses the PTE Accessed bit, similar to
that of the virtual address spaces monitoring primitives.  It supports
only user memory pages, as idle pages tracking does.  If the monitoring
target physical memory address range contains non-user memory pages,
access check of the pages will do nothing but simply treat the pages as
not accessed.

Link: https://lkml.kernel.org/r/20211012205711.29216-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:45 -07:00
SeongJae Park 2f0b548c9f mm/damon/schemes: implement statistics feature 
To tune the DAMON-based operation schemes, knowing how many and how
large regions are affected by each of the schemes will be helful.  Those
stats could be used for not only the tuning, but also monitoring of the
working set size and the number of regions, if the scheme does not
change the program behavior too much.

For the reason, this implements the statistics for the schemes.  The
total number and size of the regions that each scheme is applied are
exported to users via '->stat_count' and '->stat_sz' of 'struct damos'.
Admins can also check the number by reading 'schemes' debugfs file.  The
last two integers now represents the stats.  To allow collecting the
stats without changing the program behavior, this also adds new scheme
action, 'DAMOS_STAT'.  Note that 'DAMOS_STAT' is not only making no
memory operation actions, but also does not reset the age of regions.

Link: https://lkml.kernel.org/r/20211001125604.29660-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:44 -07:00
SeongJae Park 6dea8add4d mm/damon/vaddr: support DAMON-based Operation Schemes 
This makes DAMON's default primitives for virtual address spaces to
support DAMON-based Operation Schemes (DAMOS) by implementing actions
application functions and registering it to the monitoring context.  The
implementation simply links 'madvise()' for related DAMOS actions.  That
is, 'madvise(MADV_WILLNEED)' is called for 'WILLNEED' DAMOS action and
similar for other actions ('COLD', 'PAGEOUT', 'HUGEPAGE', 'NOHUGEPAGE').

So, the kernel space DAMON users can now use the DAMON-based
optimizations with only small amount of code.

Link: https://lkml.kernel.org/r/20211001125604.29660-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:44 -07:00
SeongJae Park 1f366e421c mm/damon/core: implement DAMON-based Operation Schemes (DAMOS) 
In many cases, users might use DAMON for simple data access aware memory
management optimizations such as applying an operation scheme to a
memory region of a specific size having a specific access frequency for
a specific time.  For example, "page out a memory region larger than 100
MiB but having a low access frequency more than 10 minutes", or "Use THP
for a memory region larger than 2 MiB having a high access frequency for
more than 2 seconds".

Most simple form of the solution would be doing offline data access
pattern profiling using DAMON and modifying the application source code
or system configuration based on the profiling results.  Or, developing
a daemon constructed with two modules (one for access monitoring and the
other for applying memory management actions via mlock(), madvise(),
sysctl, etc) is imaginable.

To avoid users spending their time for implementation of such simple
data access monitoring-based operation schemes, this makes DAMON to
handle such schemes directly.  With this change, users can simply
specify their desired schemes to DAMON.  Then, DAMON will automatically
apply the schemes to the user-specified target processes.

Each of the schemes is composed with conditions for filtering of the
target memory regions and desired memory management action for the
target.  Specifically, the format is::

    <min/max size> <min/max access frequency> <min/max age> <action>

The filtering conditions are size of memory region, number of accesses
to the region monitored by DAMON, and the age of the region.  The age of
region is incremented periodically but reset when its addresses or
access frequency has significantly changed or the action of a scheme was
applied.  For the action, current implementation supports a few of
madvise()-like hints, ``WILLNEED``, ``COLD``, ``PAGEOUT``, ``HUGEPAGE``,
and ``NOHUGEPAGE``.

Because DAMON supports various address spaces and application of the
actions to a monitoring target region is dependent to the type of the
target address space, the application code should be implemented by each
primitives and registered to the framework.  Note that this only
implements the framework part.  Following commit will implement the
action applications for virtual address spaces primitives.

Link: https://lkml.kernel.org/r/20211001125604.29660-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:44 -07:00
SeongJae Park fda504fade mm/damon/core: account age of target regions 
Patch series "Implement Data Access Monitoring-based Memory Operation Schemes".

Introduction
============

DAMON[1] can be used as a primitive for data access aware memory
management optimizations.  For that, users who want such optimizations
should run DAMON, read the monitoring results, analyze it, plan a new
memory management scheme, and apply the new scheme by themselves.  Such
efforts will be inevitable for some complicated optimizations.

However, in many other cases, the users would simply want the system to
apply a memory management action to a memory region of a specific size
having a specific access frequency for a specific time.  For example,
"page out a memory region larger than 100 MiB keeping only rare accesses
more than 2 minutes", or "Do not use THP for a memory region larger than
2 MiB rarely accessed for more than 1 seconds".

To make the works easier and non-redundant, this patchset implements a
new feature of DAMON, which is called Data Access Monitoring-based
Operation Schemes (DAMOS).  Using the feature, users can describe the
normal schemes in a simple way and ask DAMON to execute those on its
own.

[1] https://damonitor.github.io

Evaluations
===========

DAMOS is accurate and useful for memory management optimizations.  An
experimental DAMON-based operation scheme for THP, 'ethp', removes
76.15% of THP memory overheads while preserving 51.25% of THP speedup.
Another experimental DAMON-based 'proactive reclamation' implementation,
'prcl', reduces 93.38% of residential sets and 23.63% of system memory
footprint while incurring only 1.22% runtime overhead in the best case
(parsec3/freqmine).

NOTE that the experimental THP optimization and proactive reclamation
are not for production but only for proof of concepts.

Please refer to the showcase web site's evaluation document[1] for
detailed evaluation setup and results.

[1] https://damonitor.github.io/doc/html/v34/vm/damon/eval.html

Long-term Support Trees
-----------------------

For people who want to test DAMON but using LTS kernels, there are
another couple of trees based on two latest LTS kernels respectively and
containing the 'damon/master' backports.

- For v5.4.y: https://git.kernel.org/sj/h/damon/for-v5.4.y
- For v5.10.y: https://git.kernel.org/sj/h/damon/for-v5.10.y

Sequence Of Patches
===================

The 1st patch accounts age of each region.  The 2nd patch implements the
core of the DAMON-based operation schemes feature.  The 3rd patch makes
the default monitoring primitives for virtual address spaces to support
the schemes.  From this point, the kernel space users can use DAMOS.
The 4th patch exports the feature to the user space via the debugfs
interface.  The 5th patch implements schemes statistics feature for
easier tuning of the schemes and runtime access pattern analysis, and
the 6th patch adds selftests for these changes.  Finally, the 7th patch
documents this new feature.

This patch (of 7):

DAMON can be used for data access pattern aware memory management
optimizations.  For that, users should run DAMON, read the monitoring
results, analyze it, plan a new memory management scheme, and apply the
new scheme by themselves.  It would not be too hard, but still require
some level of effort.  For complicated cases, this effort is inevitable.

That said, in many cases, users would simply want to apply an actions to
a memory region of a specific size having a specific access frequency
for a specific time.  For example, "page out a memory region larger than
100 MiB but having a low access frequency more than 10 minutes", or "Use
THP for a memory region larger than 2 MiB having a high access frequency
for more than 2 seconds".

For such optimizations, users will need to first account the age of each
region themselves.  To reduce such efforts, this implements a simple age
account of each region in DAMON.  For each aggregation step, DAMON
compares the access frequency with that from last aggregation and reset
the age of the region if the change is significant.  Else, the age is
incremented.  Also, in case of the merge of regions, the region
size-weighted average of the ages is set as the age of merged new
region.

Link: https://lkml.kernel.org/r/20211001125604.29660-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211001125604.29660-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rienjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:44 -07:00
SeongJae Park d2f272b35a include/linux/damon.h: fix kernel-doc comments for 'damon_callback' 
A few Kernel-doc comments in 'damon.h' are broken.  This fixes them.

Link: https://lkml.kernel.org/r/20210917123958.3819-5-sj@kernel.org
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:44 -07:00
Marco Elver 07e8481d3c kfence: always use static branches to guard kfence_alloc() 
Regardless of KFENCE mode (CONFIG_KFENCE_STATIC_KEYS: either using
static keys to gate allocations, or using a simple dynamic branch),
always use a static branch to avoid the dynamic branch in kfence_alloc()
if KFENCE was disabled at boot.

For CONFIG_KFENCE_STATIC_KEYS=n, this now avoids the dynamic branch if
KFENCE was disabled at boot.

To simplify, also unifies the location where kfence_allocation_gate is
read-checked to just be inline in kfence_alloc().

Link: https://lkml.kernel.org/r/20211019102524.2807208-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:43 -07:00
Marco Elver f39f21b3dd stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 
filter_irq_stacks() has little to do with the stackdepot implementation,
except that it is usually used by users (such as KASAN) of stackdepot to
reduce the stack trace.

However, filter_irq_stacks() itself is not useful without a stack trace
as obtained by stack_trace_save() and friends.

Therefore, move filter_irq_stacks() to kernel/stacktrace.c, so that new
users of filter_irq_stacks() do not have to start depending on
STACKDEPOT only for filter_irq_stacks().

Link: https://lkml.kernel.org/r/20210923104803.2620285-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:43 -07:00
Mianhan Liu a1554c0026 include/linux/mm.h: move nr_free_buffer_pages from swap.h to mm.h 
nr_free_buffer_pages could be exposed through mm.h instead of swap.h.
The advantage of this change is that it can reduce the obsolete
includes.  For example, net/ipv4/tcp.c wouldn't need swap.h any more
since it has already included mm.h.  Similarly, after checking all the
other files, it comes that tcp.c, udp.c meter.c ,...  follow the same
rule, so these files can have swap.h removed too.

Moreover, after preprocessing all the files that use
nr_free_buffer_pages, it turns out that those files have already
included mm.h.Thus, we can move nr_free_buffer_pages from swap.h to mm.h
safely.  This change will not affect the compilation of other files.

Link: https://lkml.kernel.org/r/20210912133640.1624-1-liumh1@shanghaitech.edu.cn
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Cc: Jakub Kicinski <kuba@kernel.org>
CC: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Simon Horman <horms@verge.net.au>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:43 -07:00
Stephen Kitt 53944f171a mm: remove HARDENED_USERCOPY_FALLBACK 
This has served its purpose and is no longer used.  All usercopy
violations appear to have been handled by now, any remaining instances
(or new bugs) will cause copies to be rejected.

This isn't a direct revert of commit 2d891fbc3b ("usercopy: Allow
strict enforcement of whitelists"); since usercopy_fallback is
effectively 0, the fallback handling is removed too.

This also removes the usercopy_fallback module parameter on slab_common.

Link: https://github.com/KSPP/linux/issues/153
Link: https://lkml.kernel.org/r/20210921061149.1091163-1-steve@sk2.org
Signed-off-by: Stephen Kitt <steve@sk2.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>	[defconfig change]
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E . Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:43 -07:00
Ira Weiny d2c20e51e3 mm/highmem: remove deprecated kmap_atomic 
kmap_atomic() is being deprecated in favor of kmap_local_page().

Replace the uses of kmap_atomic() within the highmem code.

On profiling clear_huge_page() using ftrace an improvement of 62% was
observed on the below setup.

Setup:-
Below data has been collected on Qualcomm's SM7250 SoC THP enabled
(kernel v4.19.113) with only CPU-0(Cortex-A55) and CPU-7(Cortex-A76)
switched on and set to max frequency, also DDR set to perf governor.

FTRACE Data:-

Base data:-
Number of iterations: 48
Mean of allocation time: 349.5 us
std deviation: 74.5 us

v4 data:-
Number of iterations: 48
Mean of allocation time: 131 us
std deviation: 32.7 us

The following simple userspace experiment to allocate
100MB(BUF_SZ) of pages and writing to it gave us a good insight,
we observed an improvement of 42% in allocation and writing timings.
-------------------------------------------------------------
Test code snippet
-------------------------------------------------------------
      clock_start();
      buf = malloc(BUF_SZ); /* Allocate 100 MB of memory */

        for(i=0; i < BUF_SZ_PAGES; i++)
        {
                *((int *)(buf + (i*PAGE_SIZE))) = 1;
        }
      clock_end();
-------------------------------------------------------------

Malloc test timings for 100MB anon allocation:-

Base data:-
Number of iterations: 100
Mean of allocation time: 31831 us
std deviation: 4286 us

v4 data:-
Number of iterations: 100
Mean of allocation time: 18193 us
std deviation: 4915 us

[willy@infradead.org: fix zero_user_segments()]
  Link: https://lkml.kernel.org/r/YYVhHCJcm2DM2G9u@casper.infradead.org

Link: https://lkml.kernel.org/r/20210204073255.20769-2-prathu.baronia@oneplus.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Prathu Baronia <prathu.baronia@oneplus.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:43 -07:00
David Hildenbrand f7892d8e28 memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED 
Let's add a flag that corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED,
indicating that we're dealing with a memory region that is never
indicated in the firmware-provided memory map, but always detected and
added by a driver.

Similar to MEMBLOCK_HOTPLUG, most infrastructure has to treat such
memory regions like ordinary MEMBLOCK_NONE memory regions -- for
example, when selecting memory regions to add to the vmcore for dumping
in the crashkernel via for_each_mem_range().

However, especially kexec_file is not supposed to select such memblocks
via for_each_free_mem_range() / for_each_free_mem_range_reverse() to
place kexec images, similar to how we handle
IORESOURCE_SYSRAM_DRIVER_MANAGED without CONFIG_ARCH_KEEP_MEMBLOCK.

We'll make sure that memory hotplug code sets the flag where applicable
(IORESOURCE_SYSRAM_DRIVER_MANAGED) next.  This prepares architectures
that need CONFIG_ARCH_KEEP_MEMBLOCK, such as arm64, for virtio-mem
support.

Note that kexec *must not* indicate this memory to the second kernel and
*must not* place kexec-images on this memory.  Let's add a comment to
kexec_walk_memblock(), documenting how we handle MEMBLOCK_DRIVER_MANAGED
now just like using IORESOURCE_SYSRAM_DRIVER_MANAGED in
locate_mem_hole_callback() for kexec_walk_resources().

Also note that MEMBLOCK_HOTPLUG cannot be reused due to different
semantics:
	MEMBLOCK_HOTPLUG: memory is indicated as "System RAM" in the
	firmware-provided memory map and added to the system early during
	boot; kexec *has to* indicate this memory to the second kernel and
	can place kexec-images on this memory. After memory hotunplug,
	kexec has to be re-armed. We mostly ignore this flag when
	"movable_node" is not set on the kernel command line, because
	then we're told to not care about hotunpluggability of such
	memory regions.

	MEMBLOCK_DRIVER_MANAGED: memory is not indicated as "System RAM" in
	the firmware-provided memory map; this memory is always detected
	and added to the system by a driver; memory might not actually be
	physically hotunpluggable. kexec *must not* indicate this memory to
	the second kernel and *must not* place kexec-images on this memory.

Link: https://lkml.kernel.org/r/20211004093605.5830-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shahab Vahedi <shahab@synopsys.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:42 -07:00
David Hildenbrand 952eea9b01 memblock: allow to specify flags with memblock_add_node() 
We want to specify flags when hotplugging memory.  Let's prepare to pass
flags to memblock_add_node() by adjusting all existing users.

Note that when hotplugging memory the system is already up and running
and we might have concurrent memblock users: for example, while we're
hotplugging memory, kexec_file code might search for suitable memory
regions to place kexec images.  It's important to add the memory
directly to memblock via a single call with the right flags, instead of
adding the memory first and apply flags later: otherwise, concurrent
memblock users might temporarily stumble over memblocks with wrong
flags, which will be important in a follow-up patch that introduces a
new flag to properly handle add_memory_driver_managed().

Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Shahab Vahedi <shahab@synopsys.com>	[arch/arc]
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-06 13:30:42 -07:00