mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-04 10:12:16 +09:00
39152ee51b
In order to quickly find a ToPA entry by its page offset in the buffer, we're using a reverse lookup table. The problem with it is that it's a large array of mostly similar pointers, especially so now that we're using high order allocations from the page allocator. Because its size is limited to whatever is the maximum for kmalloc(), it places a limit on the number of ToPA entries per buffer, and therefore, on the total buffer size, which otherwise doesn't have to be there. Replace the reverse lookup table with a simple runtime lookup. With the high order AUX allocations in place, the runtime penalty of such a lookup is much smaller and in cases where all entries in a ToPA table are of the same size, the complexity is O(1). Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20190821124727.73310-7-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.