Add the alloc_flags parameter to allocate_slab() and new_slab() so it can be used to determine if spinning is allowed, independently from gfp flags. refill_objects() passes SLAB_ALLOC_DEFAULT because it can only be reached from contexts that allow spinning. Also change how trynode_flags are constructed in ___slab_alloc() to achieve the same "do not upgrade to GFP_NOWAIT" by using masking instead of a branch. It will now also not upgrade in cases where gfp is weaker than GFP_NOWAIT (i.e. lacks __GFP_KSWAPD_RECLAIM) but doesn't come from kmalloc_nolock() - which is more correct anyway. During the masking keep also existing __GFP_NOMEMALLOC (pointed out by Sashiko) and __GFP_ACCOUNT. Previously the hardcoded GFP_NOWAIT would eliminate them, but it's not a big problem that would need a separate fix. Signed-off-by: Vlastimil Babka (SUSE) --- mm/slub.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 98b79e5e7679..8f6ca3d5fdfa 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3378,9 +3378,10 @@ static __always_inline void unaccount_slab(struct slab *slab, int order, } /* Allocate and initialize a slab without building its freelist. */ -static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) +static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, + unsigned int alloc_flags, int node) { - bool allow_spin = gfpflags_allow_spinning(flags); + bool allow_spin = alloc_flags_allow_spinning(alloc_flags); struct slab *slab; struct kmem_cache_order_objects oo = s->oo; gfp_t alloc_gfp; @@ -3438,15 +3439,17 @@ static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) return slab; } -static struct slab *new_slab(struct kmem_cache *s, gfp_t flags, int node) +static struct slab *new_slab(struct kmem_cache *s, gfp_t flags, + unsigned int alloc_flags, int node) { if (unlikely(flags & GFP_SLAB_BUG_MASK)) flags = kmalloc_fix_flags(flags); WARN_ON_ONCE(s->ctor && (flags & __GFP_ZERO)); - return allocate_slab(s, - flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); + flags &= GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK; + + return allocate_slab(s, flags, alloc_flags, node); } static void __free_slab(struct kmem_cache *s, struct slab *slab, bool allow_spin) @@ -4467,25 +4470,22 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, * 1) try to get a partial slab from target node only by having * __GFP_THISNODE in pc.flags for get_from_partial() * 2) if 1) failed, try to allocate a new slab from target node with - * GPF_NOWAIT | __GFP_THISNODE opportunistically + * (at most) GFP_NOWAIT | __GFP_THISNODE opportunistically * 3) if 2) failed, retry with original gfpflags which will allow * get_from_partial() try partial lists of other nodes before * potentially allocating new page from other nodes */ if (unlikely(node != NUMA_NO_NODE && !(gfpflags & __GFP_THISNODE) && try_thisnode)) { - if (unlikely(!allow_spin)) - /* Do not upgrade gfp to NOWAIT from more restrictive mode */ - trynode_flags = gfpflags | __GFP_THISNODE; - else - trynode_flags = GFP_NOWAIT | __GFP_THISNODE; + trynode_flags &= GFP_NOWAIT | __GFP_NOMEMALLOC | __GFP_ACCOUNT; + trynode_flags |= __GFP_NOWARN | __GFP_THISNODE; } object = get_from_partial(s, node, trynode_flags, ac); if (object) goto success; - slab = new_slab(s, trynode_flags, node); + slab = new_slab(s, trynode_flags, ac->alloc_flags, node); if (unlikely(!slab)) { if (node != NUMA_NO_NODE && !(gfpflags & __GFP_THISNODE) @@ -7231,7 +7231,7 @@ refill_objects(struct kmem_cache *s, void **p, gfp_t gfp, unsigned int min, new_slab: - slab = new_slab(s, gfp, local_node); + slab = new_slab(s, gfp, SLAB_ALLOC_DEFAULT, local_node); if (!slab) goto out; @@ -7579,7 +7579,7 @@ static void early_kmem_cache_node_alloc(int node) BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node)); - slab = new_slab(kmem_cache_node, GFP_NOWAIT, node); + slab = new_slab(kmem_cache_node, GFP_NOWAIT, SLAB_ALLOC_DEFAULT, node); BUG_ON(!slab); if (slab_nid(slab) != node) { -- 2.54.0