From: Chengming Zhou zhouchengming@bytedance.com
mainline inclusion from mainline-v6.8-rc1 commit 24c6a097b5a270e05c6e99a99da66b91be81fd7d category: performance bugzilla: https://gitee.com/openeuler/kernel/issues/I9CSFJ CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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The get_partial() interface used in ___slab_alloc() may return a single object in the "kmem_cache_debug(s)" case, in which we will just return the "freelist" object.
Move this handling up to prepare for later changes.
And the "pfmemalloc_match()" part is not needed for node partial slab, since we already check this in the get_partial_node().
Signed-off-by: Chengming Zhou zhouchengming@bytedance.com Reviewed-by: Vlastimil Babka vbabka@suse.cz Tested-by: Hyeonggon Yoo 42.hyeyoo@gmail.com Reviewed-by: Hyeonggon Yoo 42.hyeyoo@gmail.com Signed-off-by: Vlastimil Babka vbabka@suse.cz Signed-off-by: ZhangPeng zhangpeng362@huawei.com --- mm/slub.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c index f7940048138c..3df5fa2d7421 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3216,8 +3216,21 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, pc.slab = &slab; pc.orig_size = orig_size; freelist = get_partial(s, node, &pc); - if (freelist) - goto check_new_slab; + if (freelist) { + if (kmem_cache_debug(s)) { + /* + * For debug caches here we had to go through + * alloc_single_from_partial() so just store the + * tracking info and return the object. + */ + if (s->flags & SLAB_STORE_USER) + set_track(s, freelist, TRACK_ALLOC, addr); + + return freelist; + } + + goto retry_load_slab; + }
slub_put_cpu_ptr(s->cpu_slab); slab = new_slab(s, gfpflags, node); @@ -3253,20 +3266,6 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
inc_slabs_node(s, slab_nid(slab), slab->objects);
-check_new_slab: - - if (kmem_cache_debug(s)) { - /* - * For debug caches here we had to go through - * alloc_single_from_partial() so just store the tracking info - * and return the object - */ - if (s->flags & SLAB_STORE_USER) - set_track(s, freelist, TRACK_ALLOC, addr); - - return freelist; - } - if (unlikely(!pfmemalloc_match(slab, gfpflags))) { /* * For !pfmemalloc_match() case we don't load freelist so that