On 3/4/22 07:34, Hyeonggon Yoo wrote: > SLUB sets number of minimum partial slabs for node (min_partial) > using set_min_partial(). SLUB holds at least min_partial slabs even if > they're empty to avoid excessive use of page allocator. > > set_min_partial() limits value of min_partial limits value of > min_partial MIN_PARTIAL and MAX_PARTIAL. As set_min_partial() can be > called by min_partial_store() too, Only limit value of min_partial > in kmem_cache_open() so that it can be changed to value that a user wants. > > [ rientjes@xxxxxxxxxx: Fold set_min_partial() into its callers ] > > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> > --- > mm/slub.c | 14 +++----------- > 1 file changed, 3 insertions(+), 11 deletions(-) > > diff --git a/mm/slub.c b/mm/slub.c > index 6f0ebadd8f30..f9ae983a3dc6 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -3981,15 +3981,6 @@ static int init_kmem_cache_nodes(struct kmem_cache *s) > return 1; > } > > -static void set_min_partial(struct kmem_cache *s, unsigned long min) > -{ > - if (min < MIN_PARTIAL) > - min = MIN_PARTIAL; > - else if (min > MAX_PARTIAL) > - min = MAX_PARTIAL; > - s->min_partial = min; > -} > - > static void set_cpu_partial(struct kmem_cache *s) > { > #ifdef CONFIG_SLUB_CPU_PARTIAL > @@ -4196,7 +4187,8 @@ static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags) > * The larger the object size is, the more slabs we want on the partial > * list to avoid pounding the page allocator excessively. > */ > - set_min_partial(s, ilog2(s->size) / 2); > + s->min_partial = min_t(unsigned long, MAX_PARTIAL, ilog2(s->size) / 2); > + s->min_partial = max_t(unsigned long, MIN_PARTIAL, s->min_partial); > > set_cpu_partial(s); > > @@ -5361,7 +5353,7 @@ static ssize_t min_partial_store(struct kmem_cache *s, const char *buf, > if (err) > return err; > > - set_min_partial(s, min); > + s->min_partial = min; > return length; > } > SLAB_ATTR(min_partial);