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| author | Serapheim Dimitropoulos <[email protected]> | 2020-06-26 18:06:50 -0700 |
|---|---|---|
| committer | GitHub <[email protected]> | 2020-06-26 18:06:50 -0700 |
| commit | ec1fea4516ac2f0c08d31d6308929298d1b281d0 (patch) | |
| tree | 20d1e31cd17d117b5d1d31f750f197e18c82acb3 /include/os/linux/spl | |
| parent | 7b232e93548a187beb5490314dad181f9ce6b17c (diff) | |
Use percpu_counter for obj_alloc counter of Linux-backed caches
A previous commit enabled the tracking of object allocations
in Linux-backed caches from the SPL layer for debuggability.
The commit is: 9a170fc6fe54f1e852b6c39630fe5ef2bbd97c16
Unfortunately, it also introduced minor performance regressions
that were highlighted by the ZFS perf test-suite. Within Delphix
we found that the regression would be from -1%, all the way up
to -8% for some workloads.
This commit brings performance back up to par by creating a
separate counter for those caches and making it a percpu in
order to avoid lock-contention.
The initial performance testing was done by myself, and the
final round was conducted by @tonynguien who was also the one
that discovered the regression and highlighted the culprit.
Reviewed-by: Matt Ahrens <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Serapheim Dimitropoulos <[email protected]>
Closes #10397
Diffstat (limited to 'include/os/linux/spl')
| -rw-r--r-- | include/os/linux/spl/sys/kmem_cache.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/os/linux/spl/sys/kmem_cache.h b/include/os/linux/spl/sys/kmem_cache.h index 5667382f7..ed63f4000 100644 --- a/include/os/linux/spl/sys/kmem_cache.h +++ b/include/os/linux/spl/sys/kmem_cache.h @@ -202,6 +202,7 @@ typedef struct spl_kmem_cache { uint64_t skc_slab_max; /* Slab max historic */ uint64_t skc_obj_total; /* Obj total current */ uint64_t skc_obj_alloc; /* Obj alloc current */ + struct percpu_counter skc_linux_alloc; /* Linux-backed Obj alloc */ uint64_t skc_obj_max; /* Obj max historic */ uint64_t skc_obj_deadlock; /* Obj emergency deadlocks */ uint64_t skc_obj_emergency; /* Obj emergency current */ |