From patchwork Thu Jun 10 17:39:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 12313659 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 3458AC48BE0 for ; Thu, 10 Jun 2021 17:41:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18757613E1 for ; Thu, 10 Jun 2021 17:41:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230313AbhFJRmz (ORCPT ); Thu, 10 Jun 2021 13:42:55 -0400 Received: from mail-qt1-f169.google.com ([209.85.160.169]:41729 "EHLO mail-qt1-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229823AbhFJRmy (ORCPT ); Thu, 10 Jun 2021 13:42:54 -0400 Received: by mail-qt1-f169.google.com with SMTP id o20so459059qtr.8; Thu, 10 Jun 2021 10:40:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=L28iRO6SUEtE91D7ICwGxj4nFRKMyweEgpKq5b01EUg=; b=o663Rj2B9r2LAkjk9i3Ni4/ESh/nLsYN0teUWxIw3O9O8xdn9tQ9LeQqinPCgTcT5V s2wV5xe8cWi4OroqcsfTTYQVv9qUhU/jjqRDPnezGuZ7zxEzKLSIgXkQ2QMf0pR1o8KE 1135EY9ZCAA0FVhEOngag9N5fbLWr924c0flV9tIEuQgGXyIqUEKhzbtGHsLHm0tAZJe azTGMD6XkOGIVeMBRSjkXZwDZBRBEsmauKsYdAB+zz4hgh1qnY6R05qZUZs6Id8OEIZn +RHUjSMudSOXHMDMYgxa1g3P7SBH40eHmkEDV9YDp6rTQvPxuRBNKJEH4Iu1yz1wOzPZ rRXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=L28iRO6SUEtE91D7ICwGxj4nFRKMyweEgpKq5b01EUg=; b=Uuc5zy6+KpjJh6ulRIlLwmaLz+3JVsoQTA8DYDdEs5qGnI50SveKTsZ71BU6r6nk+Z 4F8KKWqmRR+UgUzQ4TBWlqw4BmVwAL4iIg8tUiC4aZdQl8eIzZkohay8iUPNjTYRK7Nn mKPhCzTo1Gw/OdNGkBTCyte0OyEKnFUugRkR8+IkzB8pQrFk77b5SR5WlX77EEpV+bfF O5NUvBj9wkTrsgps0dqV3MADmZc+JQpMtPVYg80HugcolvKUFUqaIUPnKzwYTAlCXJ6d 6lFLJsJmEW8UxD2c2BwddPE7VjVjPYzJqF9MMgE6+MvWsfNQjHcZWG89tFbpiahLVUm1 EU8g== X-Gm-Message-State: AOAM530U/CvLU0yprCkfWBfUdMAm0R7X4dmpqnqubFDLum8pWwrBMtSe WEm+9vjEOnekB7fN5pkrXTc= X-Google-Smtp-Source: ABdhPJwiWSWQ/Mhfu4E2MHk1NB3HMaJeM+p3ntz/gsAXtB2yQ0JvJ2o/kDiwM5AGTClfKEDPpboSyA== X-Received: by 2002:a05:622a:ca:: with SMTP id p10mr790496qtw.83.1623346797672; Thu, 10 Jun 2021 10:39:57 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:be7a]) by smtp.gmail.com with ESMTPSA id q7sm2582169qki.92.2021.06.10.10.39.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Jun 2021 10:39:57 -0700 (PDT) From: Dan Schatzberg To: Andrew Morton Cc: linux-block@vger.kernel.org (open list:BLOCK LAYER), linux-kernel@vger.kernel.org (open list), cgroups@vger.kernel.org (open list:CONTROL GROUP (CGROUP)), linux-mm@kvack.org (open list:MEMORY MANAGEMENT), Ming Lei , Jens Axboe Subject: [PATCH 1/3] loop: Use worker per cgroup instead of kworker Date: Thu, 10 Jun 2021 10:39:42 -0700 Message-Id: <20210610173944.1203706-2-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210610173944.1203706-1-schatzberg.dan@gmail.com> References: <20210610173944.1203706-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Existing uses of loop device may have multiple cgroups reading/writing to the same device. Simply charging resources for I/O to the backing file could result in priority inversion where one cgroup gets synchronously blocked, holding up all other I/O to the loop device. In order to avoid this priority inversion, we use a single workqueue where each work item is a "struct loop_worker" which contains a queue of struct loop_cmds to issue. The loop device maintains a tree mapping blk css_id -> loop_worker. This allows each cgroup to independently make forward progress issuing I/O to the backing file. There is also a single queue for I/O associated with the rootcg which can be used in cases of extreme memory shortage where we cannot allocate a loop_worker. The locking for the tree and queues is fairly heavy handed - we acquire a per-loop-device spinlock any time either is accessed. The existing implementation serializes all I/O through a single thread anyways, so I don't believe this is any worse. Fixes-from: Colin Ian King Reviewed-by: Ming Lei Acked-by: Jens Axboe Signed-off-by: Dan Schatzberg --- drivers/block/loop.c | 209 ++++++++++++++++++++++++++++++++++++------- drivers/block/loop.h | 12 ++- 2 files changed, 187 insertions(+), 34 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 95c570f5923f..fc4a0186d381 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -71,7 +71,6 @@ #include #include #include -#include #include #include #include @@ -84,6 +83,8 @@ #include +#define LOOP_IDLE_WORKER_TIMEOUT (60 * HZ) + static DEFINE_IDR(loop_index_idr); static DEFINE_MUTEX(loop_ctl_mutex); @@ -921,27 +922,95 @@ static void loop_config_discard(struct loop_device *lo) q->limits.discard_alignment = 0; } -static void loop_unprepare_queue(struct loop_device *lo) +struct loop_worker { + struct rb_node rb_node; + struct work_struct work; + struct list_head cmd_list; + struct list_head idle_list; + struct loop_device *lo; + struct cgroup_subsys_state *css; + unsigned long last_ran_at; +}; + +static void loop_workfn(struct work_struct *work); +static void loop_rootcg_workfn(struct work_struct *work); +static void loop_free_idle_workers(struct timer_list *timer); + +#ifdef CONFIG_BLK_CGROUP +static inline int queue_on_root_worker(struct cgroup_subsys_state *css) { - kthread_flush_worker(&lo->worker); - kthread_stop(lo->worker_task); + return !css || css == blkcg_root_css; } - -static int loop_kthread_worker_fn(void *worker_ptr) +#else +static inline int queue_on_root_worker(struct cgroup_subsys_state *css) { - current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; - return kthread_worker_fn(worker_ptr); + return !css; } +#endif -static int loop_prepare_queue(struct loop_device *lo) +static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) { - kthread_init_worker(&lo->worker); - lo->worker_task = kthread_run(loop_kthread_worker_fn, - &lo->worker, "loop%d", lo->lo_number); - if (IS_ERR(lo->worker_task)) - return -ENOMEM; - set_user_nice(lo->worker_task, MIN_NICE); - return 0; + struct rb_node **node = &(lo->worker_tree.rb_node), *parent = NULL; + struct loop_worker *cur_worker, *worker = NULL; + struct work_struct *work; + struct list_head *cmd_list; + + spin_lock_irq(&lo->lo_work_lock); + + if (queue_on_root_worker(cmd->css)) + goto queue_work; + + node = &lo->worker_tree.rb_node; + + while (*node) { + parent = *node; + cur_worker = container_of(*node, struct loop_worker, rb_node); + if (cur_worker->css == cmd->css) { + worker = cur_worker; + break; + } else if ((long)cur_worker->css < (long)cmd->css) { + node = &(*node)->rb_left; + } else { + node = &(*node)->rb_right; + } + } + if (worker) + goto queue_work; + + worker = kzalloc(sizeof(struct loop_worker), GFP_NOWAIT | __GFP_NOWARN); + /* + * In the event we cannot allocate a worker, just queue on the + * rootcg worker + */ + if (!worker) + goto queue_work; + + worker->css = cmd->css; + css_get(worker->css); + INIT_WORK(&worker->work, loop_workfn); + INIT_LIST_HEAD(&worker->cmd_list); + INIT_LIST_HEAD(&worker->idle_list); + worker->lo = lo; + rb_link_node(&worker->rb_node, parent, node); + rb_insert_color(&worker->rb_node, &lo->worker_tree); +queue_work: + if (worker) { + /* + * We need to remove from the idle list here while + * holding the lock so that the idle timer doesn't + * free the worker + */ + if (!list_empty(&worker->idle_list)) + list_del_init(&worker->idle_list); + work = &worker->work; + cmd_list = &worker->cmd_list; + } else { + work = &lo->rootcg_work; + cmd_list = &lo->rootcg_cmd_list; + } + list_add_tail(&cmd->list_entry, cmd_list); + queue_work(lo->workqueue, work); + spin_unlock_irq(&lo->lo_work_lock); } static void loop_update_rotational(struct loop_device *lo) @@ -1127,12 +1196,23 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, !file->f_op->write_iter) lo->lo_flags |= LO_FLAGS_READ_ONLY; - error = loop_prepare_queue(lo); - if (error) + lo->workqueue = alloc_workqueue("loop%d", + WQ_UNBOUND | WQ_FREEZABLE, + 0, + lo->lo_number); + if (!lo->workqueue) { + error = -ENOMEM; goto out_unlock; + } set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0); + INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn); + INIT_LIST_HEAD(&lo->rootcg_cmd_list); + INIT_LIST_HEAD(&lo->idle_worker_list); + lo->worker_tree = RB_ROOT; + timer_setup(&lo->timer, loop_free_idle_workers, + TIMER_DEFERRABLE); lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO; lo->lo_device = bdev; lo->lo_backing_file = file; @@ -1200,6 +1280,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) int err = 0; bool partscan = false; int lo_number; + struct loop_worker *pos, *worker; mutex_lock(&lo->lo_mutex); if (WARN_ON_ONCE(lo->lo_state != Lo_rundown)) { @@ -1219,6 +1300,18 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) /* freeze request queue during the transition */ blk_mq_freeze_queue(lo->lo_queue); + destroy_workqueue(lo->workqueue); + spin_lock_irq(&lo->lo_work_lock); + list_for_each_entry_safe(worker, pos, &lo->idle_worker_list, + idle_list) { + list_del(&worker->idle_list); + rb_erase(&worker->rb_node, &lo->worker_tree); + css_put(worker->css); + kfree(worker); + } + spin_unlock_irq(&lo->lo_work_lock); + del_timer_sync(&lo->timer); + spin_lock_irq(&lo->lo_lock); lo->lo_backing_file = NULL; spin_unlock_irq(&lo->lo_lock); @@ -1255,7 +1348,6 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) partscan = lo->lo_flags & LO_FLAGS_PARTSCAN && bdev; lo_number = lo->lo_number; - loop_unprepare_queue(lo); out_unlock: mutex_unlock(&lo->lo_mutex); if (partscan) { @@ -2026,7 +2118,7 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, } else #endif cmd->css = NULL; - kthread_queue_work(&lo->worker, &cmd->work); + loop_queue_work(lo, cmd); return BLK_STS_OK; } @@ -2056,26 +2148,82 @@ static void loop_handle_cmd(struct loop_cmd *cmd) } } -static void loop_queue_work(struct kthread_work *work) +static void loop_set_timer(struct loop_device *lo) +{ + timer_reduce(&lo->timer, jiffies + LOOP_IDLE_WORKER_TIMEOUT); +} + +static void loop_process_work(struct loop_worker *worker, + struct list_head *cmd_list, struct loop_device *lo) { - struct loop_cmd *cmd = - container_of(work, struct loop_cmd, work); + int orig_flags = current->flags; + struct loop_cmd *cmd; - loop_handle_cmd(cmd); + current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; + spin_lock_irq(&lo->lo_work_lock); + while (!list_empty(cmd_list)) { + cmd = container_of( + cmd_list->next, struct loop_cmd, list_entry); + list_del(cmd_list->next); + spin_unlock_irq(&lo->lo_work_lock); + + loop_handle_cmd(cmd); + cond_resched(); + + spin_lock_irq(&lo->lo_work_lock); + } + + /* + * We only add to the idle list if there are no pending cmds + * *and* the worker will not run again which ensures that it + * is safe to free any worker on the idle list + */ + if (worker && !work_pending(&worker->work)) { + worker->last_ran_at = jiffies; + list_add_tail(&worker->idle_list, &lo->idle_worker_list); + loop_set_timer(lo); + } + spin_unlock_irq(&lo->lo_work_lock); + current->flags = orig_flags; } -static int loop_init_request(struct blk_mq_tag_set *set, struct request *rq, - unsigned int hctx_idx, unsigned int numa_node) +static void loop_workfn(struct work_struct *work) { - struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); + struct loop_worker *worker = + container_of(work, struct loop_worker, work); + loop_process_work(worker, &worker->cmd_list, worker->lo); +} - kthread_init_work(&cmd->work, loop_queue_work); - return 0; +static void loop_rootcg_workfn(struct work_struct *work) +{ + struct loop_device *lo = + container_of(work, struct loop_device, rootcg_work); + loop_process_work(NULL, &lo->rootcg_cmd_list, lo); +} + +static void loop_free_idle_workers(struct timer_list *timer) +{ + struct loop_device *lo = container_of(timer, struct loop_device, timer); + struct loop_worker *pos, *worker; + + spin_lock_irq(&lo->lo_work_lock); + list_for_each_entry_safe(worker, pos, &lo->idle_worker_list, + idle_list) { + if (time_is_after_jiffies(worker->last_ran_at + + LOOP_IDLE_WORKER_TIMEOUT)) + break; + list_del(&worker->idle_list); + rb_erase(&worker->rb_node, &lo->worker_tree); + css_put(worker->css); + kfree(worker); + } + if (!list_empty(&lo->idle_worker_list)) + loop_set_timer(lo); + spin_unlock_irq(&lo->lo_work_lock); } static const struct blk_mq_ops loop_mq_ops = { .queue_rq = loop_queue_rq, - .init_request = loop_init_request, .complete = lo_complete_rq, }; @@ -2164,6 +2312,7 @@ static int loop_add(struct loop_device **l, int i) mutex_init(&lo->lo_mutex); lo->lo_number = i; spin_lock_init(&lo->lo_lock); + spin_lock_init(&lo->lo_work_lock); disk->major = LOOP_MAJOR; disk->first_minor = i << part_shift; disk->fops = &lo_fops; diff --git a/drivers/block/loop.h b/drivers/block/loop.h index a3c04f310672..9289c1cd6374 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -14,7 +14,6 @@ #include #include #include -#include #include /* Possible states of device */ @@ -54,8 +53,13 @@ struct loop_device { spinlock_t lo_lock; int lo_state; - struct kthread_worker worker; - struct task_struct *worker_task; + spinlock_t lo_work_lock; + struct workqueue_struct *workqueue; + struct work_struct rootcg_work; + struct list_head rootcg_cmd_list; + struct list_head idle_worker_list; + struct rb_root worker_tree; + struct timer_list timer; bool use_dio; bool sysfs_inited; @@ -66,7 +70,7 @@ struct loop_device { }; struct loop_cmd { - struct kthread_work work; + struct list_head list_entry; bool use_aio; /* use AIO interface to handle I/O */ atomic_t ref; /* only for aio */ long ret; From patchwork Thu Jun 10 17:39:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 12313657 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 22940C48BDF for ; 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Thu, 10 Jun 2021 10:39:59 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:be7a]) by smtp.gmail.com with ESMTPSA id t8sm2542697qtp.7.2021.06.10.10.39.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Jun 2021 10:39:59 -0700 (PDT) From: Dan Schatzberg To: Andrew Morton Cc: linux-block@vger.kernel.org (open list:BLOCK LAYER), linux-kernel@vger.kernel.org (open list), cgroups@vger.kernel.org (open list:CONTROL GROUP (CGROUP)), linux-mm@kvack.org (open list:MEMORY MANAGEMENT), Johannes Weiner , Tejun Heo , Chris Down , Jens Axboe , Shakeel Butt Subject: [PATCH 2/3] mm: Charge active memcg when no mm is set Date: Thu, 10 Jun 2021 10:39:43 -0700 Message-Id: <20210610173944.1203706-3-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210610173944.1203706-1-schatzberg.dan@gmail.com> References: <20210610173944.1203706-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org set_active_memcg() worked for kernel allocations but was silently ignored for user pages. This patch establishes a precedence order for who gets charged: 1. If there is a memcg associated with the page already, that memcg is charged. This happens during swapin. 2. If an explicit mm is passed, mm->memcg is charged. This happens during page faults, which can be triggered in remote VMs (eg gup). 3. Otherwise consult the current process context. If there is an active_memcg, use that. Otherwise, current->mm->memcg. Previously, if a NULL mm was passed to mem_cgroup_charge (case 3) it would always charge the root cgroup. Now it looks up the active_memcg first (falling back to charging the root cgroup if not set). Signed-off-by: Dan Schatzberg Acked-by: Johannes Weiner Acked-by: Tejun Heo Acked-by: Chris Down Acked-by: Jens Axboe Reviewed-by: Shakeel Butt Reviewed-by: Michal Koutný --- mm/filemap.c | 2 +- mm/memcontrol.c | 41 +++++++++++++++++++++++++++-------------- mm/shmem.c | 4 ++-- 3 files changed, 30 insertions(+), 17 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index ba1068a1837f..bde9c167c056 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -872,7 +872,7 @@ noinline int __add_to_page_cache_locked(struct page *page, page->index = offset; if (!huge) { - error = mem_cgroup_charge(page, current->mm, gfp); + error = mem_cgroup_charge(page, NULL, gfp); if (error) goto error; charged = true; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4e6c6658ca0d..919736ee656b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -902,13 +902,24 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) } EXPORT_SYMBOL(mem_cgroup_from_task); +static __always_inline struct mem_cgroup *active_memcg(void) +{ + if (in_interrupt()) + return this_cpu_read(int_active_memcg); + else + return current->active_memcg; +} + /** * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg. * @mm: mm from which memcg should be extracted. It can be NULL. * - * Obtain a reference on mm->memcg and returns it if successful. Otherwise - * root_mem_cgroup is returned. However if mem_cgroup is disabled, NULL is - * returned. + * Obtain a reference on mm->memcg and returns it if successful. If mm + * is NULL, then the memcg is chosen as follows: + * 1) The active memcg, if set. + * 2) current->mm->memcg, if available + * 3) root memcg + * If mem_cgroup is disabled, NULL is returned. */ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) { @@ -926,8 +937,17 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) * counting is disabled on the root level in the * cgroup core. See CSS_NO_REF. */ - if (unlikely(!mm)) - return root_mem_cgroup; + if (unlikely(!mm)) { + memcg = active_memcg(); + if (unlikely(memcg)) { + /* remote memcg must hold a ref */ + css_get(&memcg->css); + return memcg; + } + mm = current->mm; + if (unlikely(!mm)) + return root_mem_cgroup; + } rcu_read_lock(); do { @@ -940,14 +960,6 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) } EXPORT_SYMBOL(get_mem_cgroup_from_mm); -static __always_inline struct mem_cgroup *active_memcg(void) -{ - if (in_interrupt()) - return this_cpu_read(int_active_memcg); - else - return current->active_memcg; -} - static __always_inline bool memcg_kmem_bypass(void) { /* Allow remote memcg charging from any context. */ @@ -6716,7 +6728,8 @@ static int __mem_cgroup_charge(struct page *page, struct mem_cgroup *memcg, * @gfp_mask: reclaim mode * * Try to charge @page to the memcg that @mm belongs to, reclaiming - * pages according to @gfp_mask if necessary. + * pages according to @gfp_mask if necessary. if @mm is NULL, try to + * charge to the active memcg. * * Do not use this for pages allocated for swapin. * diff --git a/mm/shmem.c b/mm/shmem.c index 34d84465ce3e..9af4b2173fe9 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1695,7 +1695,7 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, { struct address_space *mapping = inode->i_mapping; struct shmem_inode_info *info = SHMEM_I(inode); - struct mm_struct *charge_mm = vma ? vma->vm_mm : current->mm; + struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL; struct swap_info_struct *si; struct page *page = NULL; swp_entry_t swap; @@ -1828,7 +1828,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, } sbinfo = SHMEM_SB(inode->i_sb); - charge_mm = vma ? vma->vm_mm : current->mm; + charge_mm = vma ? vma->vm_mm : NULL; page = pagecache_get_page(mapping, index, FGP_ENTRY | FGP_HEAD | FGP_LOCK, 0); From patchwork Thu Jun 10 17:39:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 12313663 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 BB9DAC48BDF for ; Thu, 10 Jun 2021 17:41:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A485C613F5 for ; Thu, 10 Jun 2021 17:41:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231140AbhFJRnN (ORCPT ); Thu, 10 Jun 2021 13:43:13 -0400 Received: from mail-qk1-f173.google.com ([209.85.222.173]:35552 "EHLO mail-qk1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230452AbhFJRnJ (ORCPT ); Thu, 10 Jun 2021 13:43:09 -0400 Received: by mail-qk1-f173.google.com with SMTP id j189so28228072qkf.2; Thu, 10 Jun 2021 10:41:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=tJIm18e4PpawbVoKgbHVrGJrxEY+IxOXNktYagljzSs=; b=QdXJaINwy/NpNcHfO6r+pZO7yxptiQfjs8olLYZlteZrLcCfhawLTv/sm/ZXiyIvkq MuwF31YELaSBsWzo4eZ8lx9NNQ/x3zb2BrHhhFSP4pGeg9OI4fgFeUEynH9qv0ToCqy9 rVVsWsv1PWppqQ/x+ajUCzRl5gMbqkxvvoaShvIwCFf9KMGAfXYLO2/veCp7+SkELo+M FHBgvxzKSL/MSLvA4TVTBjLDZlfDKWUZaNaWvL/7cNRjGlmHn4op5AFbTyMxRfbvwmTn Z78QRlZGA1KT9tT1JpRVRw/zk4Be8/4/PPUtbYWTJ29BGASmIr7KjZ+gtyCkAAa8Ciwr aRqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=tJIm18e4PpawbVoKgbHVrGJrxEY+IxOXNktYagljzSs=; b=ke9DE7DHCdtpw+fMiJJA+diss4JH3jylRdixogamSmf7CT57jVpZK8PHiaUsYIVTjf s5kF30SrfziaTjXe9y4nxmqiG7AmJRH7Pb40I6hycR/fFa9j7U1c+oSU5+pqJEOufrNv 34i+B7vCGGvR3p+D9tf9eGjbNRFs/KrLiTfiGECHLpolymmA8ay9oNRRTEq5FpLi03dv zScuneoQiA5SGbQwTuXvap0BFBfRFzQ0/3iMeDJBDnQ6tqToxviiY5H8jk13kX2JwujA ndvyzCfOkXuNB2LJCxdd+Ny2kat+6SN0HDqnhaoZsw/7/CATl8uLTeqVUwWUi20HvUxP Kd8Q== X-Gm-Message-State: AOAM533FmPWcmeAZC38lR51D+sfgzar40N4swzL6Q6j3F1s9jpsxluhS pzAjmuavXwham8oUxMhD3h6jUYEumLmkyA== X-Google-Smtp-Source: ABdhPJzNsA8mpG1QH1phmDuCkqfzvwRflB+jk+YhkTbnLsGobBVg/k69jshudORFoFO6BYHq2/Ktyg== X-Received: by 2002:a37:a505:: with SMTP id o5mr641495qke.355.1623346801224; Thu, 10 Jun 2021 10:40:01 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:be7a]) by smtp.gmail.com with ESMTPSA id w2sm2567401qkf.88.2021.06.10.10.40.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Jun 2021 10:40:00 -0700 (PDT) From: Dan Schatzberg To: Andrew Morton Cc: linux-block@vger.kernel.org (open list:BLOCK LAYER), linux-kernel@vger.kernel.org (open list), cgroups@vger.kernel.org (open list:CONTROL GROUP (CGROUP)), linux-mm@kvack.org (open list:MEMORY MANAGEMENT), Johannes Weiner , Jens Axboe Subject: [PATCH 3/3] loop: Charge i/o to mem and blk cg Date: Thu, 10 Jun 2021 10:39:44 -0700 Message-Id: <20210610173944.1203706-4-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210610173944.1203706-1-schatzberg.dan@gmail.com> References: <20210610173944.1203706-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The current code only associates with the existing blkcg when aio is used to access the backing file. This patch covers all types of i/o to the backing file and also associates the memcg so if the backing file is on tmpfs, memory is charged appropriately. This patch also exports cgroup_get_e_css and int_active_memcg so it can be used by the loop module. Signed-off-by: Dan Schatzberg Acked-by: Johannes Weiner Acked-by: Jens Axboe --- drivers/block/loop.c | 61 +++++++++++++++++++++++++------------- drivers/block/loop.h | 3 +- include/linux/memcontrol.h | 6 ++++ kernel/cgroup/cgroup.c | 1 + mm/memcontrol.c | 1 + 5 files changed, 51 insertions(+), 21 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index fc4a0186d381..5198d8ad181c 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -78,6 +78,7 @@ #include #include #include +#include #include "loop.h" @@ -516,8 +517,6 @@ static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2) { struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb); - if (cmd->css) - css_put(cmd->css); cmd->ret = ret; lo_rw_aio_do_completion(cmd); } @@ -578,8 +577,6 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, cmd->iocb.ki_complete = lo_rw_aio_complete; cmd->iocb.ki_flags = IOCB_DIRECT; cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); - if (cmd->css) - kthread_associate_blkcg(cmd->css); if (rw == WRITE) ret = call_write_iter(file, &cmd->iocb, &iter); @@ -587,7 +584,6 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, ret = call_read_iter(file, &cmd->iocb, &iter); lo_rw_aio_do_completion(cmd); - kthread_associate_blkcg(NULL); if (ret != -EIOCBQUEUED) cmd->iocb.ki_complete(&cmd->iocb, ret, 0); @@ -928,7 +924,7 @@ struct loop_worker { struct list_head cmd_list; struct list_head idle_list; struct loop_device *lo; - struct cgroup_subsys_state *css; + struct cgroup_subsys_state *blkcg_css; unsigned long last_ran_at; }; @@ -957,7 +953,7 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) spin_lock_irq(&lo->lo_work_lock); - if (queue_on_root_worker(cmd->css)) + if (queue_on_root_worker(cmd->blkcg_css)) goto queue_work; node = &lo->worker_tree.rb_node; @@ -965,10 +961,10 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) while (*node) { parent = *node; cur_worker = container_of(*node, struct loop_worker, rb_node); - if (cur_worker->css == cmd->css) { + if (cur_worker->blkcg_css == cmd->blkcg_css) { worker = cur_worker; break; - } else if ((long)cur_worker->css < (long)cmd->css) { + } else if ((long)cur_worker->blkcg_css < (long)cmd->blkcg_css) { node = &(*node)->rb_left; } else { node = &(*node)->rb_right; @@ -980,13 +976,18 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) worker = kzalloc(sizeof(struct loop_worker), GFP_NOWAIT | __GFP_NOWARN); /* * In the event we cannot allocate a worker, just queue on the - * rootcg worker + * rootcg worker and issue the I/O as the rootcg */ - if (!worker) + if (!worker) { + cmd->blkcg_css = NULL; + if (cmd->memcg_css) + css_put(cmd->memcg_css); + cmd->memcg_css = NULL; goto queue_work; + } - worker->css = cmd->css; - css_get(worker->css); + worker->blkcg_css = cmd->blkcg_css; + css_get(worker->blkcg_css); INIT_WORK(&worker->work, loop_workfn); INIT_LIST_HEAD(&worker->cmd_list); INIT_LIST_HEAD(&worker->idle_list); @@ -1306,7 +1307,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) idle_list) { list_del(&worker->idle_list); rb_erase(&worker->rb_node, &lo->worker_tree); - css_put(worker->css); + css_put(worker->blkcg_css); kfree(worker); } spin_unlock_irq(&lo->lo_work_lock); @@ -2111,13 +2112,18 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, } /* always use the first bio's css */ + cmd->blkcg_css = NULL; + cmd->memcg_css = NULL; #ifdef CONFIG_BLK_CGROUP - if (cmd->use_aio && rq->bio && rq->bio->bi_blkg) { - cmd->css = &bio_blkcg(rq->bio)->css; - css_get(cmd->css); - } else + if (rq->bio && rq->bio->bi_blkg) { + cmd->blkcg_css = &bio_blkcg(rq->bio)->css; +#ifdef CONFIG_MEMCG + cmd->memcg_css = + cgroup_get_e_css(cmd->blkcg_css->cgroup, + &memory_cgrp_subsys); +#endif + } #endif - cmd->css = NULL; loop_queue_work(lo, cmd); return BLK_STS_OK; @@ -2129,13 +2135,28 @@ static void loop_handle_cmd(struct loop_cmd *cmd) const bool write = op_is_write(req_op(rq)); struct loop_device *lo = rq->q->queuedata; int ret = 0; + struct mem_cgroup *old_memcg = NULL; if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { ret = -EIO; goto failed; } + if (cmd->blkcg_css) + kthread_associate_blkcg(cmd->blkcg_css); + if (cmd->memcg_css) + old_memcg = set_active_memcg( + mem_cgroup_from_css(cmd->memcg_css)); + ret = do_req_filebacked(lo, rq); + + if (cmd->blkcg_css) + kthread_associate_blkcg(NULL); + + if (cmd->memcg_css) { + set_active_memcg(old_memcg); + css_put(cmd->memcg_css); + } failed: /* complete non-aio request */ if (!cmd->use_aio || ret) { @@ -2214,7 +2235,7 @@ static void loop_free_idle_workers(struct timer_list *timer) break; list_del(&worker->idle_list); rb_erase(&worker->rb_node, &lo->worker_tree); - css_put(worker->css); + css_put(worker->blkcg_css); kfree(worker); } if (!list_empty(&lo->idle_worker_list)) diff --git a/drivers/block/loop.h b/drivers/block/loop.h index 9289c1cd6374..cd24a81e00e6 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -76,7 +76,8 @@ struct loop_cmd { long ret; struct kiocb iocb; struct bio_vec *bvec; - struct cgroup_subsys_state *css; + struct cgroup_subsys_state *blkcg_css; + struct cgroup_subsys_state *memcg_css; }; /* Support for loadable transfer modules */ diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index bd0644d3a6df..360e61de53d7 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1230,6 +1230,12 @@ static inline struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) return NULL; } +static inline +struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css) +{ + return NULL; +} + static inline void mem_cgroup_put(struct mem_cgroup *memcg) { } diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 74e3cc801615..90329cfff48d 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -577,6 +577,7 @@ struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgrp, rcu_read_unlock(); return css; } +EXPORT_SYMBOL_GPL(cgroup_get_e_css); static void cgroup_get_live(struct cgroup *cgrp) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 919736ee656b..ae1f5d0cb581 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -78,6 +78,7 @@ struct mem_cgroup *root_mem_cgroup __read_mostly; /* Active memory cgroup to use from an interrupt context */ DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg); +EXPORT_PER_CPU_SYMBOL_GPL(int_active_memcg); /* Socket memory accounting disabled? */ static bool cgroup_memory_nosocket __ro_after_init;