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| author | Tomasz Majchrzak <tomasz.majchrzak@intel.com> | 2016-06-24 14:20:16 +0200 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2016-07-20 00:20:28 +0200 |
| commit | 0e5313e2d4ef93bdf6c22dad647d28635b86472a (patch) | |
| tree | b470429e5ae7c501d920a12550bf76592bac04d0 /arch | |
| parent | md: add missing sysfs_notify on array_state update (diff) | |
| download | linux-0e5313e2d4ef93bdf6c22dad647d28635b86472a.tar.xz linux-0e5313e2d4ef93bdf6c22dad647d28635b86472a.zip | |
raid10: improve random reads performance
RAID10 random read performance is lower than expected due to excessive spinlock
utilisation which is required mostly for rebuild/resync. Simplify allow_barrier
as it's in IO path and encounters a lot of unnecessary congestion.
As lower_barrier just takes a lock in order to decrement a counter, convert
counter (nr_pending) into atomic variable and remove the spin lock. There is
also a congestion for wake_up (it uses lock internally) so call it only when
it's really needed. As wake_up is not called constantly anymore, ensure process
waiting to raise a barrier is notified when there are no more waiting IOs.
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions