From: Vlastimil Babka <vbabka@suse.cz>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Christoph Lameter <cl@linux.com>,
David Rientjes <rientjes@google.com>,
Pekka Enberg <penberg@kernel.org>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mike Galbraith <efault@gmx.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Thomas Gleixner <tglx@linutronix.de>,
Mel Gorman <mgorman@techsingularity.net>,
Jesper Dangaard Brouer <brouer@redhat.com>,
Jann Horn <jannh@google.com>, Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH v3 19/35] mm, slub: move reset of c->page and freelist out of deactivate_slab()
Date: Thu, 29 Jul 2021 15:21:16 +0200 [thread overview]
Message-ID: <20210729132132.19691-20-vbabka@suse.cz> (raw)
In-Reply-To: <20210729132132.19691-1-vbabka@suse.cz>
deactivate_slab() removes the cpu slab by merging the cpu freelist with slab's
freelist and putting the slab on the proper node's list. It also sets the
respective kmem_cache_cpu pointers to NULL.
By extracting the kmem_cache_cpu operations from the function, we can make it
not dependent on disabled irqs.
Also if we return a single free pointer from ___slab_alloc, we no longer have
to assign kmem_cache_cpu.page before deactivation or care if somebody preempted
us and assigned a different page to our kmem_cache_cpu in the process.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
mm/slub.c | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 50a4add8983d..7a8554eb3d96 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2192,10 +2192,13 @@ static void init_kmem_cache_cpus(struct kmem_cache *s)
}
/*
- * Remove the cpu slab
+ * Finishes removing the cpu slab. Merges cpu's freelist with page's freelist,
+ * unfreezes the slabs and puts it on the proper list.
+ * Assumes the slab has been already safely taken away from kmem_cache_cpu
+ * by the caller.
*/
static void deactivate_slab(struct kmem_cache *s, struct page *page,
- void *freelist, struct kmem_cache_cpu *c)
+ void *freelist)
{
enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE };
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
@@ -2324,9 +2327,6 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page,
discard_slab(s, page);
stat(s, FREE_SLAB);
}
-
- c->page = NULL;
- c->freelist = NULL;
}
/*
@@ -2451,10 +2451,16 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
{
- stat(s, CPUSLAB_FLUSH);
- deactivate_slab(s, c->page, c->freelist, c);
+ void *freelist = c->freelist;
+ struct page *page = c->page;
+ c->page = NULL;
+ c->freelist = NULL;
c->tid = next_tid(c->tid);
+
+ deactivate_slab(s, page, freelist);
+
+ stat(s, CPUSLAB_FLUSH);
}
/*
@@ -2739,7 +2745,10 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
local_irq_restore(flags);
goto reread_page;
}
- deactivate_slab(s, page, c->freelist, c);
+ freelist = c->freelist;
+ c->page = NULL;
+ c->freelist = NULL;
+ deactivate_slab(s, page, freelist);
local_irq_restore(flags);
new_slab:
@@ -2818,11 +2827,7 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
return_single:
local_irq_save(flags);
- if (unlikely(c->page))
- flush_slab(s, c);
- c->page = page;
-
- deactivate_slab(s, page, get_freepointer(s, freelist), c);
+ deactivate_slab(s, page, get_freepointer(s, freelist));
local_irq_restore(flags);
return freelist;
}
--
2.32.0
next prev parent reply other threads:[~2021-07-29 13:22 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-29 13:20 [PATCH v3 00/35] SLUB: reduce irq disabled scope and make it RT compatible Vlastimil Babka
2021-07-29 13:20 ` [PATCH v3 01/35] mm, slub: don't call flush_all() from slab_debug_trace_open() Vlastimil Babka
2021-07-29 13:20 ` [PATCH v3 02/35] mm, slub: allocate private object map for debugfs listings Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 03/35] mm, slub: allocate private object map for validate_slab_cache() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 04/35] mm, slub: don't disable irq for debug_check_no_locks_freed() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 05/35] mm, slub: remove redundant unfreeze_partials() from put_cpu_partial() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 06/35] mm, slub: unify cmpxchg_double_slab() and __cmpxchg_double_slab() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 07/35] mm, slub: extract get_partial() from new_slab_objects() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 08/35] mm, slub: dissolve new_slab_objects() into ___slab_alloc() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 09/35] mm, slub: return slab page from get_partial() and set c->page afterwards Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 10/35] mm, slub: restructure new page checks in ___slab_alloc() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 11/35] mm, slub: simplify kmem_cache_cpu and tid setup Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 12/35] mm, slub: move disabling/enabling irqs to ___slab_alloc() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 13/35] mm, slub: do initial checks in ___slab_alloc() with irqs enabled Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 14/35] mm, slub: move disabling irqs closer to get_partial() in ___slab_alloc() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 15/35] mm, slub: restore irqs around calling new_slab() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 16/35] mm, slub: validate slab from partial list or page allocator before making it cpu slab Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 17/35] mm, slub: check new pages with restored irqs Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 18/35] mm, slub: stop disabling irqs around get_partial() Vlastimil Babka
2021-07-29 13:21 ` Vlastimil Babka [this message]
2021-07-29 13:21 ` [PATCH v3 20/35] mm, slub: make locking in deactivate_slab() irq-safe Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 21/35] mm, slub: call deactivate_slab() without disabling irqs Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 22/35] mm, slub: move irq control into unfreeze_partials() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 23/35] mm, slub: discard slabs in unfreeze_partials() without irqs disabled Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 24/35] mm, slub: detach whole partial list at once in unfreeze_partials() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 25/35] mm, slub: separate detaching of partial list in unfreeze_partials() from unfreezing Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 26/35] mm, slub: only disable irq with spin_lock in __unfreeze_partials() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 27/35] mm, slub: don't disable irqs in slub_cpu_dead() Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 28/35] mm, slab: make flush_slab() possible to call with irqs enabled Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 29/35] mm: slub: Move flush_cpu_slab() invocations __free_slab() invocations out of IRQ context Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 30/35] mm: slub: Make object_map_lock a raw_spinlock_t Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 31/35] mm, slub: optionally save/restore irqs in slab_[un]lock()/ Vlastimil Babka
2021-07-29 15:43 ` Mel Gorman
2021-07-29 13:21 ` [PATCH v3 32/35] mm, slub: make slab_lock() disable irqs with PREEMPT_RT Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 33/35] mm, slub: protect put_cpu_partial() with disabled irqs instead of cmpxchg Vlastimil Babka
2021-07-29 15:42 ` Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 34/35] mm, slub: use migrate_disable() on PREEMPT_RT Vlastimil Babka
2021-07-29 13:21 ` [PATCH v3 35/35] mm, slub: convert kmem_cpu_slab protection to local_lock Vlastimil Babka
2021-07-29 15:24 ` [PATCH v3 00/35] SLUB: reduce irq disabled scope and make it RT compatible Sebastian Andrzej Siewior
2021-07-29 15:27 ` Vlastimil Babka
2021-07-29 15:29 ` Sebastian Andrzej Siewior
2021-07-29 15:30 ` Sebastian Andrzej Siewior
2021-07-29 15:31 ` Vlastimil Babka
2021-07-29 15:47 ` Vlastimil Babka
2021-07-30 9:19 ` Sebastian Andrzej Siewior
2021-08-04 12:05 ` Mel Gorman
2021-08-04 12:14 ` Vlastimil Babka
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