From: "Vlastimil Babka (SUSE)" <vbabka@kernel.org>
To: Harry Yoo <harry@kernel.org>
Cc: Hao Li <hao.li@linux.dev>, Christoph Lameter <cl@gentwo.org>,
David Rientjes <rientjes@google.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
Suren Baghdasaryan <surenb@google.com>,
Alexei Starovoitov <ast@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Shakeel Butt <shakeel.butt@linux.dev>,
Alexander Potapenko <glider@google.com>,
Marco Elver <elver@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
"Vlastimil Babka (SUSE)" <vbabka@kernel.org>
Subject: [PATCH RFC 14/15] mm/slab: replace __GFP_NO_OBJ_EXT with SLAB_ALLOC_NO_RECURSE for sheaves
Date: Tue, 09 Jun 2026 11:17:59 +0200 [thread overview]
Message-ID: <20260609-slab_alloc_flags-v1-14-2bf4a4b9b526@kernel.org> (raw)
In-Reply-To: <20260609-slab_alloc_flags-v1-0-2bf4a4b9b526@kernel.org>
Finish the switch away from __GFP_NO_OBJ_EXT by replacing it with
SLAB_ALLOC_NO_RECURSE when allocating empty sheaves. Pass alloc_flags to
[__]alloc_empty_sheaf(). Callers that can't be part of a recursive
kmalloc() chain simply pass SLAB_ALLOC_DEFAULT. Use kmalloc_flags()
instead of kzalloc() for allocating the sheaf.
This leaves __GFP_NO_OBJ_EXT with no users, to be removed next.
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
---
mm/slub.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 8a655636dee6..26ec015efdba 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2756,7 +2756,7 @@ static inline void *setup_object(struct kmem_cache *s, void *object)
}
static struct slab_sheaf *__alloc_empty_sheaf(struct kmem_cache *s, gfp_t gfp,
- unsigned int capacity)
+ unsigned int alloc_flags, unsigned int capacity)
{
struct slab_sheaf *sheaf;
size_t sheaf_size;
@@ -2767,10 +2767,10 @@ static struct slab_sheaf *__alloc_empty_sheaf(struct kmem_cache *s, gfp_t gfp,
* bucket)
*/
if (s->flags & SLAB_KMALLOC)
- gfp |= __GFP_NO_OBJ_EXT;
+ alloc_flags |= SLAB_ALLOC_NO_RECURSE;
sheaf_size = struct_size(sheaf, objects, capacity);
- sheaf = kzalloc(sheaf_size, gfp);
+ sheaf = kmalloc_flags(sheaf_size, gfp | __GFP_ZERO, alloc_flags, NUMA_NO_NODE);
if (unlikely(!sheaf))
return NULL;
@@ -2783,20 +2783,20 @@ static struct slab_sheaf *__alloc_empty_sheaf(struct kmem_cache *s, gfp_t gfp,
}
static inline struct slab_sheaf *alloc_empty_sheaf(struct kmem_cache *s,
- gfp_t gfp)
+ gfp_t gfp, unsigned int alloc_flags)
{
- if (gfp & __GFP_NO_OBJ_EXT)
+ if (alloc_flags & SLAB_ALLOC_NO_RECURSE)
return NULL;
gfp &= ~OBJCGS_CLEAR_MASK;
- return __alloc_empty_sheaf(s, gfp, s->sheaf_capacity);
+ return __alloc_empty_sheaf(s, gfp, alloc_flags, s->sheaf_capacity);
}
static void free_empty_sheaf(struct kmem_cache *s, struct slab_sheaf *sheaf)
{
/*
- * If the sheaf was created with __GFP_NO_OBJ_EXT flag then its
+ * If the sheaf was created with SLAB_ALLOC_NO_RECURSE flag then its
* corresponding extension is NULL and alloc_tag_sub() will throw a
* warning, therefore replace NULL with CODETAG_EMPTY to indicate
* that the extension for this sheaf is expected to be NULL.
@@ -4673,7 +4673,7 @@ __pcs_replace_empty_main(struct kmem_cache *s, struct slub_percpu_sheaves *pcs,
return NULL;
if (!empty) {
- empty = alloc_empty_sheaf(s, gfp);
+ empty = alloc_empty_sheaf(s, gfp, alloc_flags);
if (!empty)
return NULL;
}
@@ -5047,7 +5047,7 @@ kmem_cache_prefill_sheaf(struct kmem_cache *s, gfp_t gfp, unsigned int size)
if (unlikely(size > s->sheaf_capacity)) {
- sheaf = __alloc_empty_sheaf(s, gfp, size);
+ sheaf = __alloc_empty_sheaf(s, gfp, SLAB_ALLOC_DEFAULT, size);
if (!sheaf)
return NULL;
@@ -5092,7 +5092,7 @@ kmem_cache_prefill_sheaf(struct kmem_cache *s, gfp_t gfp, unsigned int size)
if (!sheaf)
- sheaf = alloc_empty_sheaf(s, gfp);
+ sheaf = alloc_empty_sheaf(s, gfp, SLAB_ALLOC_DEFAULT);
if (sheaf) {
sheaf->capacity = s->sheaf_capacity;
@@ -5376,8 +5376,7 @@ static void *__kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_f
void *ret;
VM_WARN_ON_ONCE(alloc_flags_allow_spinning(ac->alloc_flags));
- VM_WARN_ON_ONCE(gfp_flags & ~(__GFP_ACCOUNT | __GFP_ZERO |
- __GFP_NO_OBJ_EXT));
+ VM_WARN_ON_ONCE(gfp_flags & ~(__GFP_ACCOUNT | __GFP_ZERO));
if (unlikely(!size))
return ZERO_SIZE_PTR;
@@ -5890,7 +5889,7 @@ __pcs_replace_full_main(struct kmem_cache *s, struct slub_percpu_sheaves *pcs,
if (!allow_spin)
return NULL;
- empty = alloc_empty_sheaf(s, GFP_NOWAIT);
+ empty = alloc_empty_sheaf(s, GFP_NOWAIT, SLAB_ALLOC_DEFAULT);
if (empty)
goto got_empty;
@@ -6074,7 +6073,7 @@ bool __kfree_rcu_sheaf(struct kmem_cache *s, void *obj)
local_unlock(&s->cpu_sheaves->lock);
- empty = alloc_empty_sheaf(s, GFP_NOWAIT);
+ empty = alloc_empty_sheaf(s, GFP_NOWAIT, SLAB_ALLOC_DEFAULT);
if (!empty)
goto fail;
@@ -7619,7 +7618,7 @@ static int init_percpu_sheaves(struct kmem_cache *s)
if (!s->sheaf_capacity)
pcs->main = &bootstrap_sheaf;
else
- pcs->main = alloc_empty_sheaf(s, GFP_KERNEL);
+ pcs->main = alloc_empty_sheaf(s, GFP_KERNEL, SLAB_ALLOC_DEFAULT);
if (!pcs->main)
return -ENOMEM;
@@ -8485,7 +8484,8 @@ static void __init bootstrap_cache_sheaves(struct kmem_cache *s)
pcs = per_cpu_ptr(s->cpu_sheaves, cpu);
- pcs->main = __alloc_empty_sheaf(s, GFP_KERNEL, capacity);
+ pcs->main = __alloc_empty_sheaf(s, GFP_KERNEL,
+ SLAB_ALLOC_DEFAULT, capacity);
if (!pcs->main) {
failed = true;
--
2.54.0
next prev parent reply other threads:[~2026-06-09 9:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-09 9:17 [PATCH RFC 00/15] mm/slab: introduce alloc_flags and slab_alloc_context Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 01/15] mm/slab: always zero only requested size on alloc Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 02/15] mm/slab: stop inlining __slab_alloc_node() Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 03/15] mm/slab: introduce slab_alloc_context Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 04/15] mm/slab: introduce alloc_flags and SLAB_ALLOC_TRYLOCK Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 05/15] mm/slab: add alloc_flags to slab_alloc_context Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 06/15] mm/slab: replace struct partial_context with slab_alloc_context Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 07/15] mm/slab: pass alloc_flags to new slab allocation Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 08/15] mm/slab: pass alloc_flags through slab_post_alloc_hook() chain Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 09/15] mm/slab: replace slab_alloc_node() parameters with slab_alloc_context Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 10/15] mm/slab: allow kmem_cache_alloc_bulk() with any gfp flags Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 11/15] mm/slab: pass slab_alloc_context to __do_kmalloc_node() Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 12/15] mm/slab: introduce kmalloc_flags() Vlastimil Babka (SUSE)
2026-06-09 9:17 ` [PATCH RFC 13/15] mm/slab: remove __GFP_NO_OBJ_EXT usage from alloc_slab_obj_exts() Vlastimil Babka (SUSE)
2026-06-09 9:17 ` Vlastimil Babka (SUSE) [this message]
2026-06-09 9:18 ` [PATCH RFC 15/15] mm: remove the __GFP_NO_OBJ_EXT flag Vlastimil Babka (SUSE)
2026-06-09 13:35 ` [PATCH RFC 00/15] mm/slab: introduce alloc_flags and slab_alloc_context Usama Arif
2026-06-09 14:28 ` Vlastimil Babka (SUSE)
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