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70cc92a7f8
commit bafaecd11d upstream.
This one is much faster than the spinlock based fallback rwsem code,
with certain artifical benchmarks having shown 300%+ improvement on
threaded page faults etc.
Again, note the 32767-thread limit here. So this really does need that
whole "make rwsem_count_t be 64-bit and fix the BIAS values to match"
extension on top of it, but that is conceptually a totally independent
issue.
NOT TESTED! The original patch that this all was based on were tested by
KAMEZAWA Hiroyuki, but maybe I screwed up something when I created the
cleaned-up series, so caveat emptor..
Also note that it _may_ be a good idea to mark some more registers
clobbered on x86-64 in the inline asms instead of saving/restoring them.
They are inline functions, but they are only used in places where there
are not a lot of live registers _anyway_, so doing for example the
clobbers of %r8-%r11 in the asm wouldn't make the fast-path code any
worse, and would make the slow-path code smaller.
(Not that the slow-path really matters to that degree. Saving a few
unnecessary registers is the _least_ of our problems when we hit the slow
path. The instruction/cycle counting really only matters in the fast
path).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <alpine.LFD.2.00.1001121810410.17145@localhost.localdomain>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
31 lines
876 B
Makefile
31 lines
876 B
Makefile
#
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# Makefile for x86 specific library files.
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#
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obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
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lib-y := delay.o
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lib-y += thunk_$(BITS).o
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lib-y += usercopy_$(BITS).o getuser.o putuser.o
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lib-y += memcpy_$(BITS).o
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obj-y += msr.o msr-reg.o msr-reg-export.o
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ifeq ($(CONFIG_X86_32),y)
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obj-y += atomic64_32.o
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lib-y += checksum_32.o
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lib-y += strstr_32.o
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lib-y += semaphore_32.o string_32.o
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ifneq ($(CONFIG_X86_CMPXCHG64),y)
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lib-y += cmpxchg8b_emu.o
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endif
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lib-$(CONFIG_X86_USE_3DNOW) += mmx_32.o
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else
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obj-y += io_64.o iomap_copy_64.o
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lib-y += csum-partial_64.o csum-copy_64.o csum-wrappers_64.o
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lib-y += thunk_64.o clear_page_64.o copy_page_64.o
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lib-y += memmove_64.o memset_64.o
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lib-y += copy_user_64.o rwlock_64.o copy_user_nocache_64.o
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lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem_64.o
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endif
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