The patch titled
Subject: slab: use memcg_kmem_cache_wq for slab destruction operations
has been removed from the -mm tree. Its filename was
slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Tejun Heo <tj@xxxxxxxxxx>
Subject: slab: use memcg_kmem_cache_wq for slab destruction operations
If there's contention on slab_mutex, queueing the per-cache destruction
work item on the system_wq can unnecessarily create and tie up a lot of
kworkers.
Rename memcg_kmem_cache_create_wq to memcg_kmem_cache_wq and make it
global and use that workqueue for the destruction work items too. While
at it, convert the workqueue from an unbound workqueue to a per-cpu one
with concurrency limited to 1. It's generally preferable to use per-cpu
workqueues and concurrency limit of 1 is safe enough.
This is suggested by Joonsoo Kim.
Link: http://lkml.kernel.org/r/20170117235411.9408-11-tj@xxxxxxxxxx
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Reported-by: Jay Vana <jsvana@xxxxxx>
Acked-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 1 +
mm/memcontrol.c | 16 ++++++++--------
mm/slab_common.c | 2 +-
3 files changed, 10 insertions(+), 9 deletions(-)
diff -puN include/linux/memcontrol.h~slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations include/linux/memcontrol.h
--- a/include/linux/memcontrol.h~slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations
+++ a/include/linux/memcontrol.h
@@ -830,6 +830,7 @@ void memcg_kmem_uncharge(struct page *pa
#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
extern struct static_key_false memcg_kmem_enabled_key;
+extern struct workqueue_struct *memcg_kmem_cache_wq;
extern int memcg_nr_cache_ids;
void memcg_get_cache_ids(void);
diff -puN mm/memcontrol.c~slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations mm/memcontrol.c
--- a/mm/memcontrol.c~slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations
+++ a/mm/memcontrol.c
@@ -317,6 +317,8 @@ void memcg_put_cache_ids(void)
DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key);
EXPORT_SYMBOL(memcg_kmem_enabled_key);
+struct workqueue_struct *memcg_kmem_cache_wq;
+
#endif /* !CONFIG_SLOB */
/**
@@ -2143,8 +2145,6 @@ struct memcg_kmem_cache_create_work {
struct work_struct work;
};
-static struct workqueue_struct *memcg_kmem_cache_create_wq;
-
static void memcg_kmem_cache_create_func(struct work_struct *w)
{
struct memcg_kmem_cache_create_work *cw =
@@ -2176,7 +2176,7 @@ static void __memcg_schedule_kmem_cache_
cw->cachep = cachep;
INIT_WORK(&cw->work, memcg_kmem_cache_create_func);
- queue_work(memcg_kmem_cache_create_wq, &cw->work);
+ queue_work(memcg_kmem_cache_wq, &cw->work);
}
static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
@@ -5778,12 +5778,12 @@ static int __init mem_cgroup_init(void)
#ifndef CONFIG_SLOB
/*
* Kmem cache creation is mostly done with the slab_mutex held,
- * so use a special workqueue to avoid stalling all worker
- * threads in case lots of cgroups are created simultaneously.
+ * so use a workqueue with limited concurrency to avoid stalling
+ * all worker threads in case lots of cgroups are created and
+ * destroyed simultaneously.
*/
- memcg_kmem_cache_create_wq =
- alloc_ordered_workqueue("memcg_kmem_cache_create", 0);
- BUG_ON(!memcg_kmem_cache_create_wq);
+ memcg_kmem_cache_wq = alloc_workqueue("memcg_kmem_cache", 0, 1);
+ BUG_ON(!memcg_kmem_cache_wq);
#endif
cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL,
diff -puN mm/slab_common.c~slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations mm/slab_common.c
--- a/mm/slab_common.c~slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations
+++ a/mm/slab_common.c
@@ -659,7 +659,7 @@ static void kmemcg_deactivate_rcufn(stru
* initialized eariler.
*/
INIT_WORK(&s->memcg_params.deact_work, kmemcg_deactivate_workfn);
- schedule_work(&s->memcg_params.deact_work);
+ queue_work(memcg_kmem_cache_wq, &s->memcg_params.deact_work);
}
/**
_
Patches currently in -mm which might be from tj@xxxxxxxxxx are
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