filemap: add filemap_map_order0_folio() to handle order0 folio
Kernel test robot reported regressions for several benchmarks [1].
The regression are related with commit:
de74976eb65151a2f568e477fc2e0032df5b22b4 ("filemap: add filemap_map_folio_range()")
It turned out that function filemap_map_folio_range() brings these
regressions when handle folio with order0.
Add filemap_map_order0_folio() to handle order0 folio. The benefit
come from two perspectives:
- the code size is smaller (around 126 bytes)
- no loop
Testing showed the regressions reported by 0day [1] all are fixed:
commit 9f1f5b60e76d44fa: parent commit of de74976eb65151a2
commit fbdf9263a3d7fdbd: latest mm-unstable commit
commit 7fbfe2003f84686d: this fixing patch
9f1f5b60e76d44fa fbdf9263a3d7fdbd 7fbfe2003f84686d
---------------- --------------------------- ---------------------------
3843810 -21.4% 3020268 +4.6% 4018708 stress-ng.bad-altstack.ops
64061 -21.4% 50336 +4.6% 66977 stress-ng.bad-altstack.ops_per_sec
1709026 -14.4% 1462102 +2.4% 1750757 stress-ng.fork.ops
28483 -14.4% 24368 +2.4% 29179 stress-ng.fork.ops_per_sec
3685088 -53.6% 1710976 +0.5% 3702454 stress-ng.zombie.ops
56732 -65.3% 19667 +0.7% 57107 stress-ng.zombie.ops_per_sec
61874 -12.1% 54416 +0.4% 62136 vm-scalability.median
13527663 -11.7% 11942117 -0.1% 13513946 vm-scalability.throughput
4.066e+09 -11.7% 3.59e+09 -0.1% 4.061e+09 vm-scalability.workload
[1]:
https://lore.kernel.org/oe-lkp/72e017b9-deb6-44fa-91d6-716ee2c39cbc@intel.com/T/#m7d2bba30f75a9cee8eab07e5809abd9b3b206c84
Link: https://lkml.kernel.org/r/20230914134741.1937654-1-fengwei.yin@intel.com
Fixes: de74976eb65151a2f568e477fc2e0032df5b22b4 ("filemap: add filemap_map_folio_range()")
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202309111556.b2aa3d7a-oliver.sang@intel.com
Cc: Feng Tang <feng.tang@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1 file changed
