diff options
| author | Minchan Kim <minchan@kernel.org> | 2021-09-24 15:43:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-24 16:13:35 -0700 |
| commit | 243418e3925d5b5b0657ae54c322d43035e97eed (patch) | |
| tree | 5cfbc50ba58f0bfca373305e2e9b233d3b35065d /fs/buffer.c | |
| parent | b7cd9fa5ccc392d9f2269edc4cb82508632c28da (diff) | |
mm: fs: invalidate bh_lrus for only cold path
The kernel test robot reported the regression of fio.write_iops[1] with
commit 8cc621d2f45d ("mm: fs: invalidate BH LRU during page migration").
Since lru_add_drain is called frequently, invalidate bh_lrus there could
increase bh_lrus cache miss ratio, which needs more IO in the end.
This patch moves the bh_lrus invalidation from the hot path( e.g.,
zap_page_range, pagevec_release) to cold path(i.e., lru_add_drain_all,
lru_cache_disable).
Zhengjun Xing confirmed
"I test the patch, the regression reduced to -2.9%"
[1] https://lore.kernel.org/lkml/20210520083144.GD14190@xsang-OptiPlex-9020/
[2] 8cc621d2f45d, mm: fs: invalidate BH LRU during page migration
Link: https://lkml.kernel.org/r/20210907212347.1977686-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Chris Goldsworthy <cgoldswo@codeaurora.org>
Tested-by: "Xing, Zhengjun" <zhengjun.xing@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/buffer.c')
| -rw-r--r-- | fs/buffer.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index ab7573d72dd7..c615387aedca 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1425,12 +1425,16 @@ void invalidate_bh_lrus(void) } EXPORT_SYMBOL_GPL(invalidate_bh_lrus); -void invalidate_bh_lrus_cpu(int cpu) +/* + * It's called from workqueue context so we need a bh_lru_lock to close + * the race with preemption/irq. + */ +void invalidate_bh_lrus_cpu(void) { struct bh_lru *b; bh_lru_lock(); - b = per_cpu_ptr(&bh_lrus, cpu); + b = this_cpu_ptr(&bh_lrus); __invalidate_bh_lrus(b); bh_lru_unlock(); } |