]> www.infradead.org Git - users/jedix/linux-maple.git/commit
mm/mincore: improve performance by adding an unlikely hint
authorColin Ian King <colin.i.king@gmail.com>
Wed, 19 Feb 2025 08:36:07 +0000 (08:36 +0000)
committerAndrew Morton <akpm@linux-foundation.org>
Tue, 4 Mar 2025 05:50:19 +0000 (21:50 -0800)
commita2aaa19962157e02bc02fd5e11179be6afb85930
tree7d84529b24826dc761a983780435400fde9b0d54
parent4870fdab5e84256474ab17949cbe82950609b90b
mm/mincore: improve performance by adding an unlikely hint

Adding an unlikely() hint on the masked start comparison error return path
improves run-time performance of the mincore system call.

Benchmarking on an i9-12900 shows an improvement of 7ns on mincore calls
on a 256KB mmap'd region where 50% of the pages we resident.  Improvement
was from ~970 ns down to 963 ns, so a small ~0.7% improvement.

Results based on running 20 tests with turbo disabled (to reduce clock
freq turbo changes), with 10 second run per test and comparing the number
of mincores calls per second.  The % standard deviation of the 20 tests
was ~0.10%, so results are reliable.

Link: https://lkml.kernel.org/r/20250219083607.5183-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Cc: Matthew Wilcow <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/mincore.c