From patchwork Tue Mar 16 15:36:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 12142553 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=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 9239AC433E6 for ; Tue, 16 Mar 2021 15:37:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1DA43650F6 for ; Tue, 16 Mar 2021 15:37:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DA43650F6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AF1938D0015; Tue, 16 Mar 2021 11:37:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ACA158D0014; Tue, 16 Mar 2021 11:37:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8F4BD8D0015; Tue, 16 Mar 2021 11:37:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0163.hostedemail.com [216.40.44.163]) by kanga.kvack.org (Postfix) with ESMTP id 70A0D8D0014 for ; Tue, 16 Mar 2021 11:37:32 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 2B1B3180AD837 for ; Tue, 16 Mar 2021 15:37:32 +0000 (UTC) X-FDA: 77926141944.04.E90C4EE Received: from mail-qt1-f178.google.com (mail-qt1-f178.google.com [209.85.160.178]) by imf02.hostedemail.com (Postfix) with ESMTP id 2D5314080F5F for ; Tue, 16 Mar 2021 15:37:30 +0000 (UTC) Received: by mail-qt1-f178.google.com with SMTP id f12so11933510qtq.4 for ; Tue, 16 Mar 2021 08:37:30 -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=BJeF+DFkWjXvC2+py6aYx1pM4wZgsYdRz94iG+JwIjQ=; b=GoQJBLW7obUr3v6qda9xFMLeM6y9AGbo4dCEQfj6BGRVxRpRHgk1FfBdowzYTmJ2Xy 2yfzTf8noY/ILScIbrwM2SiENNgJLjQDM1RN6c1Z7F+3KA2If4Twpf2OnqwIEVq5tu0A bZH6CDApzDd1PLtJq/8QqAVkg412e1hs1pK6ugbukBHCzJpAPQ6Z7Uyy+MdOxNJVl8lH In0L+Ion5C8hFvnPRSVJZIOOPdoHM0JsXkLoxaZNjFB2ligzdpragEHG5QS1GfzSsTOo TcHZRWRh/G4mGLlk+C7HUUov7uPPjYj+7UFiEJ/e32N4+T3ngM9aywaLdGe9pOCxhJEt hzzQ== 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=BJeF+DFkWjXvC2+py6aYx1pM4wZgsYdRz94iG+JwIjQ=; b=gxpyGZWYvouyfGC5qJHQcl1ZITsh+3rZPx6cylb2hNypJPk3QI3UmvoeqJRkMRXAVC tUYmq+yGszpKS/1pwPP8eEyf0ao2Zlu1S+pyKWXHp5da4SMrBO6YJQS5DuYbKgkHfW6z xRul+V+ak9n1o6QmVWvjv/nRHhcLygbtJM+SoZG29ZFVdphvzrrlsuMXWX6/BKyCBWDN UInpO/UdQygONhV2OeJiE1tqjDtt507Ixh/YQvH+vfdohJziyVPQLeJv8WPWrM2BtnRM AXk6VWZQJ69jVbD16O12Ek8mjL8Gc78UF3MG/LDEyKx2F1vF+tHBQmGGb1ZdczCUgjd9 LXsQ== X-Gm-Message-State: AOAM533yRNcKzNiXOhtfuwTlxaUocP8aLqs4CUNwatC2gOLFCyV9sdl/ xEc3CFSErzxql7xCdESPV7s= X-Google-Smtp-Source: ABdhPJwuCUat0ipVpAbAZY+Gt6SG/1Qi6JcuoU/MbVmGoUKbejTPsR93MqLGiam1VCeIGV6iNh/e5w== X-Received: by 2002:a05:622a:34f:: with SMTP id r15mr237682qtw.107.1615909040068; Tue, 16 Mar 2021 08:37:20 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:1ee]) by smtp.gmail.com with ESMTPSA id k4sm15491144qke.13.2021.03.16.08.37.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Mar 2021 08:37:19 -0700 (PDT) From: Dan Schatzberg To: Cc: Jens Axboe , Tejun Heo , Zefan Li , Johannes Weiner , Andrew Morton , Michal Hocko , Vladimir Davydov , Hugh Dickins , Shakeel Butt , Roman Gushchin , Muchun Song , Alex Shi , Alexander Duyck , Chris Down , Yafang Shao , Wei Yang , 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) Subject: [PATCH 1/3] loop: Use worker per cgroup instead of kworker Date: Tue, 16 Mar 2021 08:36:50 -0700 Message-Id: <20210316153655.500806-2-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210316153655.500806-1-schatzberg.dan@gmail.com> References: <20210316153655.500806-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 X-Stat-Signature: kbiy6w3zqm5k3ite4edcsy58gf87z883 X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 2D5314080F5F Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf02; identity=mailfrom; envelope-from=""; helo=mail-qt1-f178.google.com; client-ip=209.85.160.178 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615909050-524063 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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. Signed-off-by: Dan Schatzberg --- drivers/block/loop.c | 207 ++++++++++++++++++++++++++++++++++++------- drivers/block/loop.h | 12 ++- 2 files changed, 182 insertions(+), 37 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index a370cde3ddd4..5c080af73caa 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -70,7 +70,6 @@ #include #include #include -#include #include #include #include @@ -83,6 +82,8 @@ #include +#define LOOP_IDLE_WORKER_TIMEOUT (60 * HZ) + static DEFINE_IDR(loop_index_idr); static DEFINE_MUTEX(loop_ctl_mutex); @@ -920,27 +921,83 @@ static void loop_config_discard(struct loop_device *lo) q->limits.discard_alignment = 0; } -static void loop_unprepare_queue(struct loop_device *lo) -{ - kthread_flush_worker(&lo->worker); - kthread_stop(lo->worker_task); -} +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 int loop_kthread_worker_fn(void *worker_ptr) -{ - current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; - return kthread_worker_fn(worker_ptr); -} +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); -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 (!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) @@ -1126,12 +1183,27 @@ 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) + error = -EFBIG; + size = get_loop_size(lo, file); + if ((loff_t)(sector_t)size != size) goto out_unlock; + lo->workqueue = alloc_workqueue("loop%d", + WQ_UNBOUND | WQ_FREEZABLE | + WQ_MEM_RECLAIM, + 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; @@ -1199,6 +1271,7 @@ 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)) { @@ -1218,6 +1291,18 @@ 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); @@ -1254,7 +1339,6 @@ 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) { @@ -2025,7 +2109,7 @@ 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; } @@ -2055,26 +2139,82 @@ 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, }; @@ -2163,6 +2303,7 @@ 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 Tue Mar 16 15:36:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 12142551 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=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,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 B0E0AC433DB for ; Tue, 16 Mar 2021 15:37:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5869F650EB for ; Tue, 16 Mar 2021 15:37:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5869F650EB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EC1368D0013; Tue, 16 Mar 2021 11:37:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E97F88D0012; Tue, 16 Mar 2021 11:37:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D12248D0013; Tue, 16 Mar 2021 11:37:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0087.hostedemail.com [216.40.44.87]) by kanga.kvack.org (Postfix) with ESMTP id AFF8C8D0012 for ; Tue, 16 Mar 2021 11:37:30 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 6E9868249980 for ; Tue, 16 Mar 2021 15:37:30 +0000 (UTC) X-FDA: 77926141860.17.7804FE1 Received: from mail-qk1-f173.google.com (mail-qk1-f173.google.com [209.85.222.173]) by imf12.hostedemail.com (Postfix) with ESMTP id E5D53350B for ; Tue, 16 Mar 2021 15:37:26 +0000 (UTC) Received: by mail-qk1-f173.google.com with SMTP id l4so35643635qkl.0 for ; Tue, 16 Mar 2021 08:37:26 -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=Io4/SuSrOnO2lgbZBjKm6Sy30ngmcZaMUy5F+H9fpyg=; b=litRM2T0M677dAg8+HS9+0ucinGZ/dprpSboNx4ygkFJPc0HA7LeXLHFrv7Q9m7k79 aUxF39PH+bvWZtQ0icKUCN/4ShHLXO2+bh72cKKbvhbVjEJDHIL0WCz61My8fhcto88B QvLWU0tlpdH7qaNFpUHjdjkJ7Asl4Hi0b3cRIqZ93FsHXczVR7keUqqqpiMBaIlsoJ5m HokRsWiOoqXWTO98zQWkfe4xQC3jTTfs0+bMx0aKRlA47CnKyFscvmsBxs3Z7jKLx+jd 1HGoBPab+GGGBMBfNjofRaLQVJrgvBq2KfmpJBH1thj4ZTg7KHcg32MgwI4IJ2rSfJh/ 2noQ== 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=Io4/SuSrOnO2lgbZBjKm6Sy30ngmcZaMUy5F+H9fpyg=; b=eqfB+hINZbbbTXDzknC0th3Wan8zGi52RTIQvT0mZrhLtn59/Yb8R8ZYdpTNgGbOwZ 0L7QgQ5s/mR3eJpSQJQDQzR/s3KHJDe7+IooKsDKxhucJpxgbQJeG8XmOrjulY5wdWwL 3anwYygMP0DTERdbM8hqJ2TLL7JfqYD+NYigkppO6fpze/Bd5/NeV6zaR4i8mfwYeOJj OwMpiVmdltCRqPs+ig4TD/79dMNQK51jJ4FC6DGsYL4jdn4eOR20pe/ls/AQioRAXYbR S430kZGOtNARoTWexBLG/1TcPf/xDOFXdkFBdJOXyrIuSggnL1rni0CvDl8FBVPep7vZ GDLg== X-Gm-Message-State: AOAM530FJtsDi3JetC3yE90FB4e1oKWC2a6c90fqTZl4vc9IGA7scU4z osCu0Ohs6U/6OQDojq34ZC8= X-Google-Smtp-Source: ABdhPJzLhmIigbpwLFc93Ups8jNMalmervLIp/mKz6S4aNI/h1o+8g1FB8LgzYpx7UXu9v1tS7X0QA== X-Received: by 2002:a37:6ca:: with SMTP id 193mr125522qkg.405.1615909045580; Tue, 16 Mar 2021 08:37:25 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:1ee]) by smtp.gmail.com with ESMTPSA id k24sm13719703qtu.35.2021.03.16.08.37.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Mar 2021 08:37:25 -0700 (PDT) From: Dan Schatzberg To: Cc: Jens Axboe , Tejun Heo , Zefan Li , Johannes Weiner , Andrew Morton , Michal Hocko , Vladimir Davydov , Hugh Dickins , Shakeel Butt , Roman Gushchin , Muchun Song , Alex Shi , Alexander Duyck , Chris Down , Yafang Shao , Wei Yang , 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) Subject: [PATCH 2/3] mm: Charge active memcg when no mm is set Date: Tue, 16 Mar 2021 08:36:51 -0700 Message-Id: <20210316153655.500806-3-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210316153655.500806-1-schatzberg.dan@gmail.com> References: <20210316153655.500806-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 X-Stat-Signature: zzz67toku1rmbjnmjzag4gyy51bafmm5 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: E5D53350B Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=mail-qk1-f173.google.com; client-ip=209.85.222.173 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615909046-879367 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: memalloc_use_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 it has configured a current->active_memcg, use that. Otherwise, current->mm->memcg. Previously, if a NULL mm was passed to mem_cgroup_try_charge (case 3) it would always charge the root cgroup. Now it looks up the current 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 Reviewed-by: Shakeel Butt --- mm/filemap.c | 2 +- mm/memcontrol.c | 14 +++++++++++--- mm/shmem.c | 4 ++-- 3 files changed, 14 insertions(+), 6 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 43700480d897..5135f330f05c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -843,7 +843,7 @@ 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 e064ac0d850a..9a1b23ed3412 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6690,7 +6690,8 @@ void mem_cgroup_calculate_protection(struct mem_cgroup *root, * @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. * * Returns 0 on success. Otherwise, an error code is returned. */ @@ -6726,8 +6727,15 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) rcu_read_unlock(); } - if (!memcg) - memcg = get_mem_cgroup_from_mm(mm); + if (!memcg) { + if (!mm) { + memcg = get_mem_cgroup_from_current(); + if (!memcg) + memcg = get_mem_cgroup_from_mm(current->mm); + } else { + memcg = get_mem_cgroup_from_mm(mm); + } + } ret = try_charge(memcg, gfp_mask, nr_pages); if (ret) diff --git a/mm/shmem.c b/mm/shmem.c index b2db4ed0fbc7..353b362c370e 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 page *page; swp_entry_t swap; int error; @@ -1816,7 +1816,7 @@ 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 Tue Mar 16 15:36:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 12142555 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=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,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 61351C433E9 for ; Tue, 16 Mar 2021 15:37:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F24DF650F6 for ; Tue, 16 Mar 2021 15:37:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F24DF650F6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CEE738D0016; Tue, 16 Mar 2021 11:37:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CA08C8D0014; Tue, 16 Mar 2021 11:37:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A7B388D0016; Tue, 16 Mar 2021 11:37:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0236.hostedemail.com [216.40.44.236]) by kanga.kvack.org (Postfix) with ESMTP id 8B8798D0014 for ; Tue, 16 Mar 2021 11:37:33 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 46AD54DC3 for ; Tue, 16 Mar 2021 15:37:33 +0000 (UTC) X-FDA: 77926141986.14.E6BE357 Received: from mail-qk1-f177.google.com (mail-qk1-f177.google.com [209.85.222.177]) by imf02.hostedemail.com (Postfix) with ESMTP id 21DF840F8C20 for ; Tue, 16 Mar 2021 15:37:31 +0000 (UTC) Received: by mail-qk1-f177.google.com with SMTP id a9so35591229qkn.13 for ; Tue, 16 Mar 2021 08:37:31 -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=SADjSKEOkix4t8p9x6JY890dWdHLGsY9Rc7Lg6faQoU=; b=rM8fq07zA9C4bo9WSbloq+ek277Q5kGSB7HNIy5MooE0Bf/vReCLqO4IviXlNiZ2aw gFCQU9fv/bm/p05hS5ZbsOFJ+grHxZU2+2COb0cuhEMZurcChMHtmgh/wQBzpehMLhBI 7u5utpXXm68vTqK72bGlfjCek7+nFC7VbUauxGyzLmY+68pwX4dfEOm3HM+kkzlwOZZu aoK9mYEyMOmLn4nf4iF05Zkme8X9tDhtgVeDxLr1SpsYTE+PyelRbgcrL7W9/EtqeXLw mXP1Rs1RBVP+kUdU5RkduPWn1/dpECrMQGZzo+5ioaoNCumIxQ9jdLWS/KWgOAgCUwcf 4gPA== 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=SADjSKEOkix4t8p9x6JY890dWdHLGsY9Rc7Lg6faQoU=; b=YHluF0aqqyr3tL0EPlroUNXddqKbFxUOoTE9KsH83DzLyy3v3+YPfTSsfeowfDHGmQ MrsbnT1AUQGWQoQCpYyewqnyGOYP6xzQRmMLucS1auR0Z+3yMzxCDMlVuGC3qgh0FuSq rW68a5BEgkxjoOGJaf0k1H9vkonfxXhbL4+qWWlhU732oT+3M7BIjOsK2jxwElgKNbvP vy9Abmd3tjReYs8e9x6WzsSJuhV72Zj9IAENCpQTDe4Xec0WcaszONJUv7Mohl2DI2s+ CQaVpBisZ0T+D7SH+aQVU6EyiXC91sg17Ok8FOU6T8YOBqBhD+YIlYvplHolr9ABLFJz c6uw== X-Gm-Message-State: AOAM533tP8vLv6l1IgWjj2pZGqj6r9c9yBlOlehLXSSGTe7JOKmQxS6t /p51vMLrfGBLxkBBJfOJwAY= X-Google-Smtp-Source: ABdhPJy7GZTEmdCMo498WUqWo9a2uGPWdWpqsedqeFm0EtTYld1vhYQOY8G7RBbK3kSdSt6fd4aawQ== X-Received: by 2002:a37:7b41:: with SMTP id w62mr195775qkc.256.1615909051073; Tue, 16 Mar 2021 08:37:31 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:1ee]) by smtp.gmail.com with ESMTPSA id h11sm10255114qtp.24.2021.03.16.08.37.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Mar 2021 08:37:30 -0700 (PDT) From: Dan Schatzberg To: Cc: Jens Axboe , Tejun Heo , Zefan Li , Johannes Weiner , Andrew Morton , Michal Hocko , Vladimir Davydov , Hugh Dickins , Shakeel Butt , Roman Gushchin , Muchun Song , Alex Shi , Alexander Duyck , Chris Down , Yafang Shao , Wei Yang , 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) Subject: [PATCH 3/3] loop: Charge i/o to mem and blk cg Date: Tue, 16 Mar 2021 08:36:52 -0700 Message-Id: <20210316153655.500806-4-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210316153655.500806-1-schatzberg.dan@gmail.com> References: <20210316153655.500806-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 X-Stat-Signature: exih4g3grgsn43sjgi14w6gn57zhqp3h X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 21DF840F8C20 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf02; identity=mailfrom; envelope-from=""; helo=mail-qk1-f177.google.com; client-ip=209.85.222.177 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615909051-235567 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 --- drivers/block/loop.c | 61 +++++++++++++++++++++++++------------- drivers/block/loop.h | 3 +- include/linux/memcontrol.h | 11 +++++++ kernel/cgroup/cgroup.c | 1 + mm/memcontrol.c | 1 + 5 files changed, 56 insertions(+), 21 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 5c080af73caa..6cf3086a2e75 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -77,6 +77,7 @@ #include #include #include +#include #include "loop.h" @@ -515,8 +516,6 @@ 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); } @@ -577,8 +576,6 @@ 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); @@ -586,7 +583,6 @@ 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); @@ -927,7 +923,7 @@ 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; }; @@ -944,7 +940,7 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) spin_lock_irq(&lo->lo_work_lock); - if (!cmd->css) + if (!cmd->blkcg_css) goto queue_work; node = &lo->worker_tree.rb_node; @@ -952,10 +948,10 @@ 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; @@ -967,13 +963,18 @@ 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); @@ -1297,7 +1298,7 @@ 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); @@ -2102,13 +2103,18 @@ 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; @@ -2120,13 +2126,28 @@ 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) { @@ -2205,7 +2226,7 @@ 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 0c04d39a7967..fd5dd961d01f 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1187,6 +1187,17 @@ static inline struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) return NULL; } +static inline struct mem_cgroup *get_mem_cgroup_from_page(struct page *page) +{ + 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 9153b20e5cc6..94c88f7221c5 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 9a1b23ed3412..f05501669e29 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;