zfs/module
Matthew Macy 033c788bd5 Restore ARC MFU/MRU pressure
The arc_adapt() function tunes LRU/MLU balance according to 4 types of
cache hits (which is passed as state agrument): ghost LRU, LRU, MRU,
ghost MRU. If this function is called with wrong cache hit (state),
adaptation will be sub-optimal and performance will suffer.

Some time ago upstream received this commit:

6950 ARC should cache compressed data) in arc_read() do next
sequence (access to ghost buffer)

Before this commit, hit to any ghost list was passed arc_adapt() before
call to arc_access() which revive element in cache and change state from
ghost to real hit.

After this commit, the order of calls was reverted and arc_adapt() is
now called only with «real» hits even if hit was in one of two ghost
lists, which renders ghost lists useless and breaks the ARC algorithm.

FreeBSD fixed this problem locally in Change D19094 / Commit r348772.

This change is an adaptation of the above commit to the current arc
code.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10548
Closes #10618
2020-12-14 12:05:24 -08:00
..
avl Fix typos in module/ 2020-01-22 13:48:59 -08:00
icp Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-09-15 21:16:58 +00:00
lua Mark lua setjmp/longjmp for powerpc weak 2020-09-22 11:43:07 -07:00
nvpair cppcheck: (warning) Possible null pointer dereference: nvh 2020-01-22 13:49:06 -08:00
spl Fix buggy procfs_list_seq_next warning 2020-09-30 16:31:37 -07:00
unicode Update build system and packaging 2018-05-29 16:00:33 -07:00
zcommon Bugfix/fix uio partial copies 2020-05-12 10:53:32 -07:00
zfs Restore ARC MFU/MRU pressure 2020-12-14 12:05:24 -08:00
.gitignore Adapt gitignore for modules 2020-01-22 13:49:05 -08:00
Makefile.in module/Makefile.in: don't run xargs if empty 2020-01-22 13:49:02 -08:00