From mboxrd@z Thu Jan 1 00:00:00 1970 From: colyli@suse.de Subject: [PATCH 3/4] bcache: use delayed kworker fo asynchronous devices registration Date: Mon, 15 Jun 2020 00:53:32 +0800 Message-ID: <20200614165333.124999-4-colyli@suse.de> References: <20200614165333.124999-1-colyli@suse.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200614165333.124999-1-colyli@suse.de> Sender: linux-block-owner@vger.kernel.org To: axboe@kernel.dk Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org, Coly Li , Hannes Reinecke List-Id: linux-bcache@vger.kernel.org From: Coly Li This patch changes the asynchronous registration kworker to a delayed kworker. There is probability queue_work() queues the async registration kworker to the same CPU (even though very little), then the process which writing sysfs interface to reigster bcache device may won't return immeidately. queue_delayed_work() in this patch will delay 10 jiffies before insert the kworker to run queue, which makes sure the registering process may always returns to user space in time. Fixes: 9e23ccf8f0a22 ("bcache: asynchronous devices registration") Signed-off-by: Coly Li Cc: Hannes Reinecke --- drivers/md/bcache/super.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 904ea9bbb5c4..a6e79083010a 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -2380,7 +2381,7 @@ static bool bch_is_open(struct block_device *bdev) } struct async_reg_args { - struct work_struct reg_work; + struct delayed_work reg_work; char *path; struct cache_sb *sb; struct cache_sb_disk *sb_disk; @@ -2391,7 +2392,7 @@ static void register_bdev_worker(struct work_struct *work) { int fail = false; struct async_reg_args *args = - container_of(work, struct async_reg_args, reg_work); + container_of(work, struct async_reg_args, reg_work.work); struct cached_dev *dc; dc = kzalloc(sizeof(*dc), GFP_KERNEL); @@ -2421,7 +2422,7 @@ static void register_cache_worker(struct work_struct *work) { int fail = false; struct async_reg_args *args = - container_of(work, struct async_reg_args, reg_work); + container_of(work, struct async_reg_args, reg_work.work); struct cache *ca; ca = kzalloc(sizeof(*ca), GFP_KERNEL); @@ -2449,11 +2450,12 @@ static void register_cache_worker(struct work_struct *work) static void register_device_aync(struct async_reg_args *args) { if (SB_IS_BDEV(args->sb)) - INIT_WORK(&args->reg_work, register_bdev_worker); + INIT_DELAYED_WORK(&args->reg_work, register_bdev_worker); else - INIT_WORK(&args->reg_work, register_cache_worker); + INIT_DELAYED_WORK(&args->reg_work, register_cache_worker); - queue_work(system_wq, &args->reg_work); + /* 10 jiffies is enough for a delay */ + queue_delayed_work(system_wq, &args->reg_work, 10); } static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, -- 2.25.0 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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 A5C4FC433E0 for ; Sun, 14 Jun 2020 16:53:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F0C3206D7 for ; Sun, 14 Jun 2020 16:53:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727036AbgFNQxt (ORCPT ); Sun, 14 Jun 2020 12:53:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:47062 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726982AbgFNQxs (ORCPT ); Sun, 14 Jun 2020 12:53:48 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 2C6D5AE00; Sun, 14 Jun 2020 16:53:51 +0000 (UTC) From: colyli@suse.de To: axboe@kernel.dk Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org, Coly Li , Hannes Reinecke Subject: [PATCH 3/4] bcache: use delayed kworker fo asynchronous devices registration Date: Mon, 15 Jun 2020 00:53:32 +0800 Message-ID: <20200614165333.124999-4-colyli@suse.de> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200614165333.124999-1-colyli@suse.de> References: <20200614165333.124999-1-colyli@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-bcache-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org Message-ID: <20200614165332.DQvklQ03ofZKaAlsswH4mi75TpZRXn9Lt4DW3sFJdR8@z> From: Coly Li This patch changes the asynchronous registration kworker to a delayed kworker. There is probability queue_work() queues the async registration kworker to the same CPU (even though very little), then the process which writing sysfs interface to reigster bcache device may won't return immeidately. queue_delayed_work() in this patch will delay 10 jiffies before insert the kworker to run queue, which makes sure the registering process may always returns to user space in time. Fixes: 9e23ccf8f0a22 ("bcache: asynchronous devices registration") Signed-off-by: Coly Li Cc: Hannes Reinecke --- drivers/md/bcache/super.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 904ea9bbb5c4..a6e79083010a 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -2380,7 +2381,7 @@ static bool bch_is_open(struct block_device *bdev) } struct async_reg_args { - struct work_struct reg_work; + struct delayed_work reg_work; char *path; struct cache_sb *sb; struct cache_sb_disk *sb_disk; @@ -2391,7 +2392,7 @@ static void register_bdev_worker(struct work_struct *work) { int fail = false; struct async_reg_args *args = - container_of(work, struct async_reg_args, reg_work); + container_of(work, struct async_reg_args, reg_work.work); struct cached_dev *dc; dc = kzalloc(sizeof(*dc), GFP_KERNEL); @@ -2421,7 +2422,7 @@ static void register_cache_worker(struct work_struct *work) { int fail = false; struct async_reg_args *args = - container_of(work, struct async_reg_args, reg_work); + container_of(work, struct async_reg_args, reg_work.work); struct cache *ca; ca = kzalloc(sizeof(*ca), GFP_KERNEL); @@ -2449,11 +2450,12 @@ static void register_cache_worker(struct work_struct *work) static void register_device_aync(struct async_reg_args *args) { if (SB_IS_BDEV(args->sb)) - INIT_WORK(&args->reg_work, register_bdev_worker); + INIT_DELAYED_WORK(&args->reg_work, register_bdev_worker); else - INIT_WORK(&args->reg_work, register_cache_worker); + INIT_DELAYED_WORK(&args->reg_work, register_cache_worker); - queue_work(system_wq, &args->reg_work); + /* 10 jiffies is enough for a delay */ + queue_delayed_work(system_wq, &args->reg_work, 10); } static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, -- 2.25.0