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spl-module-parameters.5: remove spl_kmem_cache_{expire,obj_per_slab_min}
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Both were removed in 4fbdb10 ("remove
kmem_cache module parameter KMC_EXPIRE_AGE")

Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Richard Laager <[email protected]>
Signed-off-by: Ahelenia Ziemiańska <[email protected]>
Closes openzfs#12157
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nabijaczleweli authored and behlendorf committed Jun 9, 2021
1 parent 6e01b47 commit 2fe8060
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Showing 2 changed files with 1 addition and 44 deletions.
41 changes: 0 additions & 41 deletions man/man5/spl-module-parameters.5
Original file line number Diff line number Diff line change
Expand Up @@ -14,33 +14,6 @@ Description of the different parameters to the SPL module.
.sp
.LP

.sp
.ne 2
.na
\fBspl_kmem_cache_expire\fR (uint)
.ad
.RS 12n
Cache expiration is part of default Illumos cache behavior. The idea is
that objects in magazines which have not been recently accessed should be
returned to the slabs periodically. This is known as cache aging and
when enabled objects will be typically returned after 15 seconds.
.sp
On the other hand Linux slabs are designed to never move objects back to
the slabs unless there is memory pressure. This is possible because under
Linux the cache will be notified when memory is low and objects can be
released.
.sp
By default only the Linux method is enabled. It has been shown to improve
responsiveness on low memory systems and not negatively impact the performance
of systems with more memory. This policy may be changed by setting the
\fBspl_kmem_cache_expire\fR bit mask as follows, both policies may be enabled
concurrently.
.sp
0x01 - Aging (Illumos), 0x02 - Low memory (Linux)
.sp
Default value: \fB0x02\fR
.RE

.sp
.ne 2
.na
Expand Down Expand Up @@ -85,20 +58,6 @@ take longer.
Default value: \fB8\fR
.RE

.sp
.ne 2
.na
\fBspl_kmem_cache_obj_per_slab_min\fR (uint)
.ad
.RS 12n
The minimum number of objects allowed per slab. Normally slabs will contain
\fBspl_kmem_cache_obj_per_slab\fR objects but for caches that contain very
large objects it's desirable to only have a few, or even just one, object per
slab.
.sp
Default value: \fB1\fR
.RE

.sp
.ne 2
.na
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4 changes: 1 addition & 3 deletions module/os/linux/spl/spl-kmem-cache.c
Original file line number Diff line number Diff line change
Expand Up @@ -527,9 +527,7 @@ spl_cache_flush(spl_kmem_cache_t *skc, spl_kmem_magazine_t *skm, int flush)
* Size a slab based on the size of each aligned object plus spl_kmem_obj_t.
* When on-slab we want to target spl_kmem_cache_obj_per_slab. However,
* for very small objects we may end up with more than this so as not
* to waste space in the minimal allocation of a single page. Also for
* very large objects we may use as few as spl_kmem_cache_obj_per_slab_min,
* lower than this and we will fail.
* to waste space in the minimal allocation of a single page.
*/
static int
spl_slab_size(spl_kmem_cache_t *skc, uint32_t *objs, uint32_t *size)
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