From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6120CC282E1 for ; Tue, 23 Apr 2019 22:16:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23C6D218FC for ; Tue, 23 Apr 2019 22:16:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="lmYZkXiA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbfDWWQx (ORCPT ); Tue, 23 Apr 2019 18:16:53 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:36468 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728288AbfDWWQx (ORCPT ); Tue, 23 Apr 2019 18:16:53 -0400 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3NM9gG0002693 for ; Tue, 23 Apr 2019 15:16:52 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=MtkthRXb9xr3Z6+sHE+ddzmShZROkNDy015XAdhrxgc=; b=lmYZkXiARc+GMISjiGAr6LDhoLFvNr4MU96SCAqjRj3y2G9lSSUe2X+6OHuS6ro69Jlg YiIWjRbLD+cUv0QKwgO1yC0ZvNeMUi23hEWlCv4h5B9/aRkn8ULTBmk8FSTVZwUmHmHG dlMRoglP+3++t1x0A/Eoo3ereq0i5UHobIM= Received: from maileast.thefacebook.com ([199.201.65.23]) by mx0a-00082601.pphosted.com with ESMTP id 2s25j31y0r-12 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Tue, 23 Apr 2019 15:16:52 -0700 Received: from mx-out.facebook.com (2620:10d:c0a1:3::13) by mail.thefacebook.com (2620:10d:c021:18::175) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Tue, 23 Apr 2019 15:16:50 -0700 Received: by devvm2643.prn2.facebook.com (Postfix, from userid 111017) id C2E9C1142D2E2; Tue, 23 Apr 2019 14:31:36 -0700 (PDT) Smtp-Origin-Hostprefix: devvm From: Roman Gushchin Smtp-Origin-Hostname: devvm2643.prn2.facebook.com To: Andrew Morton CC: , , , Johannes Weiner , Michal Hocko , Rik van Riel , Shakeel Butt , Christoph Lameter , Vladimir Davydov , , Roman Gushchin Smtp-Origin-Cluster: prn2c23 Subject: [PATCH v2 2/6] mm: generalize postponed non-root kmem_cache deactivation Date: Tue, 23 Apr 2019 14:31:29 -0700 Message-ID: <20190423213133.3551969-3-guro@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190423213133.3551969-1-guro@fb.com> References: <20190423213133.3551969-1-guro@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-23_08:,, signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently SLUB uses a work scheduled after an RCU grace period to deactivate a non-root kmem_cache. This mechanism can be reused for kmem_caches reparenting, but requires some generalization. Let's decouple all infrastructure (rcu callback, work callback) from the SLUB-specific code, so it can be used with SLAB as well. Also, let's rename some functions to make the code look simpler. All SLAB/SLUB-specific functions start with "__". Remove "deact_" prefix from the corresponding struct fields. Here is the graph of a new calling scheme: kmemcg_cache_deactivate() __kmemcg_cache_deactivate() SLAB/SLUB-specific kmemcg_schedule_work_after_rcu() rcu kmemcg_after_rcu_workfn() work kmemcg_cache_deactivate_after_rcu() __kmemcg_cache_deactivate_after_rcu() SLAB/SLUB-specific instead of: __kmemcg_cache_deactivate() SLAB/SLUB-specific slab_deactivate_memcg_cache_rcu_sched() SLUB-only kmemcg_deactivate_rcufn SLUB-only, rcu kmemcg_deactivate_workfn SLUB-only, work kmemcg_cache_deact_after_rcu() SLUB-only Signed-off-by: Roman Gushchin --- include/linux/slab.h | 6 ++--- mm/slab.c | 4 +++ mm/slab.h | 3 ++- mm/slab_common.c | 62 ++++++++++++++++++++------------------------ mm/slub.c | 8 +----- 5 files changed, 38 insertions(+), 45 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index 9449b19c5f10..47923c173f30 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -642,10 +642,10 @@ struct memcg_cache_params { struct list_head children_node; struct list_head kmem_caches_node; - void (*deact_fn)(struct kmem_cache *); + void (*work_fn)(struct kmem_cache *); union { - struct rcu_head deact_rcu_head; - struct work_struct deact_work; + struct rcu_head rcu_head; + struct work_struct work; }; }; }; diff --git a/mm/slab.c b/mm/slab.c index 57a332f524cf..14466a73d057 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2317,6 +2317,10 @@ void __kmemcg_cache_deactivate(struct kmem_cache *cachep) { __kmem_cache_shrink(cachep); } + +void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s) +{ +} #endif int __kmem_cache_shutdown(struct kmem_cache *cachep) diff --git a/mm/slab.h b/mm/slab.h index 6a562ca72bca..4a261c97c138 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -172,6 +172,7 @@ int __kmem_cache_shutdown(struct kmem_cache *); void __kmem_cache_release(struct kmem_cache *); int __kmem_cache_shrink(struct kmem_cache *); void __kmemcg_cache_deactivate(struct kmem_cache *s); +void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s); void slab_kmem_cache_release(struct kmem_cache *); struct seq_file; @@ -291,7 +292,7 @@ static __always_inline void memcg_uncharge_slab(struct page *page, int order, extern void slab_init_memcg_params(struct kmem_cache *); extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg); extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, - void (*deact_fn)(struct kmem_cache *)); + void (*work_fn)(struct kmem_cache *)); #else /* CONFIG_MEMCG_KMEM */ diff --git a/mm/slab_common.c b/mm/slab_common.c index 6e00bdf8618d..4e5b4292a763 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -691,17 +691,18 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, put_online_cpus(); } -static void kmemcg_deactivate_workfn(struct work_struct *work) +static void kmemcg_after_rcu_workfn(struct work_struct *work) { struct kmem_cache *s = container_of(work, struct kmem_cache, - memcg_params.deact_work); + memcg_params.work); get_online_cpus(); get_online_mems(); mutex_lock(&slab_mutex); - s->memcg_params.deact_fn(s); + s->memcg_params.work_fn(s); + s->memcg_params.work_fn = NULL; mutex_unlock(&slab_mutex); @@ -712,37 +713,28 @@ static void kmemcg_deactivate_workfn(struct work_struct *work) css_put(&s->memcg_params.memcg->css); } -static void kmemcg_deactivate_rcufn(struct rcu_head *head) +/* + * We need to grab blocking locks. Bounce to ->work. The + * work item shares the space with the RCU head and can't be + * initialized eariler. +*/ +static void kmemcg_schedule_work_after_rcu(struct rcu_head *head) { struct kmem_cache *s = container_of(head, struct kmem_cache, - memcg_params.deact_rcu_head); + memcg_params.rcu_head); - /* - * We need to grab blocking locks. Bounce to ->deact_work. The - * work item shares the space with the RCU head and can't be - * initialized eariler. - */ - INIT_WORK(&s->memcg_params.deact_work, kmemcg_deactivate_workfn); - queue_work(memcg_kmem_cache_wq, &s->memcg_params.deact_work); + INIT_WORK(&s->memcg_params.work, kmemcg_after_rcu_workfn); + queue_work(memcg_kmem_cache_wq, &s->memcg_params.work); } -/** - * slab_deactivate_memcg_cache_rcu_sched - schedule deactivation after a - * sched RCU grace period - * @s: target kmem_cache - * @deact_fn: deactivation function to call - * - * Schedule @deact_fn to be invoked with online cpus, mems and slab_mutex - * held after a sched RCU grace period. The slab is guaranteed to stay - * alive until @deact_fn is finished. This is to be used from - * __kmemcg_cache_deactivate(). - */ -void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, - void (*deact_fn)(struct kmem_cache *)) +static void kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s) { - if (WARN_ON_ONCE(is_root_cache(s)) || - WARN_ON_ONCE(s->memcg_params.deact_fn)) - return; + __kmemcg_cache_deactivate_after_rcu(s); +} + +static void kmemcg_cache_deactivate(struct kmem_cache *s) +{ + __kmemcg_cache_deactivate(s); if (s->memcg_params.root_cache->memcg_params.dying) return; @@ -750,8 +742,9 @@ void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, /* pin memcg so that @s doesn't get destroyed in the middle */ css_get(&s->memcg_params.memcg->css); - s->memcg_params.deact_fn = deact_fn; - call_rcu(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn); + WARN_ON_ONCE(s->memcg_params.work_fn); + s->memcg_params.work_fn = kmemcg_cache_deactivate_after_rcu; + call_rcu(&s->memcg_params.rcu_head, kmemcg_schedule_work_after_rcu); } void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) @@ -773,7 +766,7 @@ void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) if (!c) continue; - __kmemcg_cache_deactivate(c); + kmemcg_cache_deactivate(c); arr->entries[idx] = NULL; } mutex_unlock(&slab_mutex); @@ -866,11 +859,12 @@ static void flush_memcg_workqueue(struct kmem_cache *s) mutex_unlock(&slab_mutex); /* - * SLUB deactivates the kmem_caches through call_rcu. Make + * SLAB and SLUB deactivate the kmem_caches through call_rcu. Make * sure all registered rcu callbacks have been invoked. */ - if (IS_ENABLED(CONFIG_SLUB)) - rcu_barrier(); +#ifndef CONFIG_SLOB + rcu_barrier(); +#endif /* * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB diff --git a/mm/slub.c b/mm/slub.c index 2b9244529d76..195f61785c7d 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4033,7 +4033,7 @@ int __kmem_cache_shrink(struct kmem_cache *s) } #ifdef CONFIG_MEMCG -static void kmemcg_cache_deact_after_rcu(struct kmem_cache *s) +void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s) { /* * Called with all the locks held after a sched RCU grace period. @@ -4059,12 +4059,6 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s) */ slub_set_cpu_partial(s, 0); s->min_partial = 0; - - /* - * s->cpu_partial is checked locklessly (see put_cpu_partial), so - * we have to make sure the change is visible before shrinking. - */ - slab_deactivate_memcg_cache_rcu_sched(s, kmemcg_cache_deact_after_rcu); } #endif /* CONFIG_MEMCG */ -- 2.20.1