Commit 27125df9 authored by Harry Yoo's avatar Harry Yoo Committed by Vlastimil Babka
Browse files

mm/slab: drop the OBJEXTS_NOSPIN_ALLOC flag from enum objext_flags 



OBJEXTS_NOSPIN_ALLOC was used to remember whether a slabobj_ext vector
was allocated via kmalloc_nolock(), so that free_slab_obj_exts() could
call kfree_nolock() instead of kfree().

Now that kfree() supports freeing kmalloc_nolock() objects, this flag is
no longer needed. Instead, pass the allow_spin parameter down to
free_slab_obj_exts() to determine whether kfree_nolock() or kfree()
should be called in the free path, and free one bit in
enum objext_flags.

Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarHarry Yoo <harry.yoo@oracle.com>
Reviewed-by: default avatarHao Li <hao.li@linux.dev>
Link: https://patch.msgid.link/20260210044642.139482-3-harry.yoo@oracle.com


Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent c4d6d782

include/linux/memcontrol.h

+1 −2
Original line number Diff line number Diff line
@@ -359,8 +359,7 @@ enum objext_flags { 
	 * MEMCG_DATA_OBJEXTS.

	 */

	OBJEXTS_ALLOC_FAIL = __OBJEXTS_ALLOC_FAIL,

	/* slabobj_ext vector allocated with kmalloc_nolock() */

	OBJEXTS_NOSPIN_ALLOC = __FIRST_OBJEXT_FLAG,

	__OBJEXTS_FLAG_UNUSED = __FIRST_OBJEXT_FLAG,

	/* the next bit after the last actual flag */

	__NR_OBJEXTS_FLAGS  = (__FIRST_OBJEXT_FLAG << 1),

};

mm/slub.c

+8 −10
Original line number Diff line number Diff line
@@ -2190,8 +2190,6 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, 
			virt_to_slab(vec)->slab_cache == s);



	new_exts = (unsigned long)vec;

	if (unlikely(!allow_spin))

		new_exts |= OBJEXTS_NOSPIN_ALLOC;

#ifdef CONFIG_MEMCG

	new_exts |= MEMCG_DATA_OBJEXTS;

#endif
@@ -2229,7 +2227,7 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, 
	return 0;

}



static inline void free_slab_obj_exts(struct slab *slab)

static inline void free_slab_obj_exts(struct slab *slab, bool allow_spin)

{

	struct slabobj_ext *obj_exts;
@@ -2257,10 +2255,10 @@ static inline void free_slab_obj_exts(struct slab *slab) 
	 * the extension for obj_exts is expected to be NULL.

	 */

	mark_objexts_empty(obj_exts);

	if (unlikely(READ_ONCE(slab->obj_exts) & OBJEXTS_NOSPIN_ALLOC))

		kfree_nolock(obj_exts);

	else

	if (allow_spin)

		kfree(obj_exts);

	else

		kfree_nolock(obj_exts);

	slab->obj_exts = 0;

}
@@ -2324,7 +2322,7 @@ static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, 
	return 0;

}



static inline void free_slab_obj_exts(struct slab *slab)

static inline void free_slab_obj_exts(struct slab *slab, bool allow_spin)

{

}
@@ -3404,14 +3402,14 @@ static __always_inline void account_slab(struct slab *slab, int order, 
}



static __always_inline void unaccount_slab(struct slab *slab, int order,

					   struct kmem_cache *s)

					   struct kmem_cache *s, bool allow_spin)

{

	/*

	 * The slab object extensions should now be freed regardless of

	 * whether mem_alloc_profiling_enabled() or not because profiling

	 * might have been disabled after slab->obj_exts got allocated.

	 */

	free_slab_obj_exts(slab);

	free_slab_obj_exts(slab, allow_spin);



	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),

			    -(PAGE_SIZE << order));
@@ -3515,7 +3513,7 @@ static void __free_slab(struct kmem_cache *s, struct slab *slab, bool allow_spin 
	page->mapping = NULL;

	__ClearPageSlab(page);

	mm_account_reclaimed_pages(pages);

	unaccount_slab(slab, order, s);

	unaccount_slab(slab, order, s, allow_spin);

	if (allow_spin)

		free_frozen_pages(page, order);

	else