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| author | Andrei Vagin <[email protected]> | 2019-11-12 01:26:50 +0000 |
|---|---|---|
| committer | Thomas Gleixner <[email protected]> | 2020-01-14 11:20:47 +0000 |
| commit | 0898a16a362d436464b34fa644d0d46efc81df92 (patch) | |
| tree | f3cd76906a1a91e0037b5526961a91eaa2697e8b /fs/proc/namespaces.c | |
| parent | lib/vdso: Avoid duplication in __cvdso_clock_getres() (diff) | |
| download | kernel-0898a16a362d436464b34fa644d0d46efc81df92.tar.gz kernel-0898a16a362d436464b34fa644d0d46efc81df92.zip | |
lib/vdso: Add unlikely() hint into vdso_read_begin()
Place the branch with no concurrent write before the contended case.
Performance numbers for Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz
(more clock_gettime() cycles - the better):
| before | after
-----------------------------------
| 150252214 | 153242367
| 150301112 | 153324800
| 150392773 | 153125401
| 150373957 | 153399355
| 150303157 | 153489417
| 150365237 | 153494270
-----------------------------------
avg | 150331408 | 153345935
diff % | 2 | 0
-----------------------------------
stdev % | 0.3 | 0.1
Co-developed-by: Dmitry Safonov <[email protected]>
Signed-off-by: Andrei Vagin <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Vincenzo Frascino <[email protected]>
Reviewed-by: Vincenzo Frascino <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'fs/proc/namespaces.c')
0 files changed, 0 insertions, 0 deletions