From: "Vlastimil Babka (SUSE)" <vbabka@kernel.org>
To: Harry Yoo <harry@kernel.org>, Suren Baghdasaryan <surenb@google.com>
Cc: Hao Li <hao.li@linux.dev>, Shakeel Butt <shakeel.butt@linux.dev>,
Alexander Potapenko <glider@google.com>,
Marco Elver <elver@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@gentwo.org>,
David Rientjes <rientjes@google.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
cgroups@vger.kernel.org,
"Vlastimil Babka (SUSE)" <vbabka@kernel.org>
Subject: [PATCH RFC 02/12] mm/slab: remove objs_per_slab()
Date: Wed, 15 Jul 2026 12:10:42 +0200 [thread overview]
Message-ID: <20260715-b4-objext_split-v1-2-9a49c4ccf4c3@kernel.org> (raw)
In-Reply-To: <20260715-b4-objext_split-v1-0-9a49c4ccf4c3@kernel.org>
The function has an unused kmem_cache argument and almost nothing uses
it anyway; doing slab->objects is simpler. Remove it with the last two
users. KUNIT_EXPECT_EQ() needs a cast to avoid "error: ‘typeof’ applied
to a bit-field" but we don't need to keep a wrapper just for that.
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
---
mm/kfence/kfence_test.c | 2 +-
mm/slab.h | 6 ------
mm/slub.c | 3 +--
3 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index de2d0f7d62b1..9867c03ef0ae 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -295,7 +295,7 @@ static void *test_alloc(struct kunit *test, size_t size, gfp_t gfp, enum allocat
* memcg accounting works correctly.
*/
KUNIT_EXPECT_EQ(test, obj_to_index(s, slab, alloc), 0U);
- KUNIT_EXPECT_EQ(test, objs_per_slab(s, slab), 1);
+ KUNIT_EXPECT_EQ(test, ((unsigned int)slab->objects), 1);
if (policy == ALLOCATE_ANY)
return alloc;
diff --git a/mm/slab.h b/mm/slab.h
index f5e336b6b6b0..01535e1e2d3c 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -330,12 +330,6 @@ static inline unsigned int obj_to_index(const struct kmem_cache *cache,
return __obj_to_index(cache, slab_address(slab), obj);
}
-static inline int objs_per_slab(const struct kmem_cache *cache,
- const struct slab *slab)
-{
- return slab->objects;
-}
-
/*
* State of the slab allocator.
*
diff --git a/mm/slub.c b/mm/slub.c
index a4be70d080fb..9e25f2dce7a6 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2127,7 +2127,6 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
gfp_t gfp, unsigned int alloc_flags)
{
const bool allow_spin = alloc_flags_allow_spinning(alloc_flags);
- unsigned int objects = objs_per_slab(s, slab);
bool new_slab = alloc_flags & SLAB_ALLOC_NEW_SLAB;
unsigned long new_exts;
unsigned long old_exts;
@@ -2183,7 +2182,7 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
#endif
retry:
old_exts = READ_ONCE(slab->obj_exts);
- handle_failed_objexts_alloc(old_exts, vec, objects);
+ handle_failed_objexts_alloc(old_exts, vec, slab->objects);
if (new_slab) {
/*
--
2.55.0
next prev parent reply other threads:[~2026-07-15 10:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-15 10:10 [PATCH RFC 00/12] mm/slab, alloc_tag: reduce obj_ext memory waste Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 01/12] mm/slab: skip kfence objects in allocation profiling Vlastimil Babka (SUSE)
2026-07-15 10:10 ` Vlastimil Babka (SUSE) [this message]
2026-07-15 10:10 ` [PATCH RFC 03/12] mm: move struct slabobj_ext to mm/slab.h Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 04/12] mm/slab: make slab_obj_ext() determine object index Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 05/12] mm/slab: abstract slabobj_ext.objcg access Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 06/12] mm/slab: abstract slabobj_ext.ref access Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 07/12] mm/slab: replace slab.stride with obj_exts_in_object Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 08/12] mm/slab: change struct slabobj_ext to a union Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 09/12] mm/slab: introduce slab_obj_ext_has_codetag() Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 10/12] mm/slab: reduce slabobj_ext memory with allocation profiling disabled Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 11/12] mm/slab: add slab_needs_objcg() helper Vlastimil Babka (SUSE)
2026-07-15 10:10 ` [PATCH RFC 12/12] mm/slab: stop allocating objcg pointers when unnecessary Vlastimil Babka (SUSE)
2026-07-15 15:32 ` [PATCH RFC 00/12] mm/slab, alloc_tag: reduce obj_ext memory waste Suren Baghdasaryan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260715-b4-objext_split-v1-2-9a49c4ccf4c3@kernel.org \
--to=vbabka@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=cgroups@vger.kernel.org \
--cc=cl@gentwo.org \
--cc=elver@google.com \
--cc=glider@google.com \
--cc=hao.li@linux.dev \
--cc=harry@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rientjes@google.com \
--cc=roman.gushchin@linux.dev \
--cc=shakeel.butt@linux.dev \
--cc=surenb@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox