From patchwork Thu Feb 29 09:57:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13576936 Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B316E63CAC; Thu, 29 Feb 2024 10:03:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709201006; cv=none; b=Y2a9nCLyMRiUAWv2dpVqPYJQNN7R2O8eT2vZ6gp4GaP/a1z67x1qg3d6LRphUkJfITr3g27qGmOgw/l1Kfx1y/t+Mm6JY4WtOBwS5+ndCbrWy5lHu0prsaYpAIgUtCLL1wJFLKJRJhNIeFYj6JvsMF+q59l9hs98oNcxwJl6Y9Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709201006; c=relaxed/simple; bh=AdfUaPu0zOXRGxRzUsboVvYzUsy/7UX1uK/3ejRkSc8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=j9ciX+nCt+HWefOuw3N6xRx4OtfMy8AfHxPaVKfcoP+DHLwVsI0MuZ6AzKtPmVGkrNQelR1EBXhaPPamAvdxQmNBcsxHJ8Hxkt/Qw7dr9INQzSmYHccoblfYucPJGqiC/YCpQW+/e1tI1y10UKtNW4hn/5RsGkwhwqhaRSB6f5E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4Tlmxw3CBvz4f3khh; Thu, 29 Feb 2024 18:03:16 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id B03671A0232; Thu, 29 Feb 2024 18:03:21 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP1 (Coremail) with SMTP id cCh0CgAX5g5hVuBlFsMHFg--.11578S14; Thu, 29 Feb 2024 18:03:21 +0800 (CST) From: Yu Kuai To: xni@redhat.com, paul.e.luse@linux.intel.com, song@kernel.org, neilb@suse.com, shli@fb.com Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH md-6.9 v4 10/11] md/raid1: factor out the code to manage sequential IO Date: Thu, 29 Feb 2024 17:57:13 +0800 Message-Id: <20240229095714.926789-11-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240229095714.926789-1-yukuai1@huaweicloud.com> References: <20240229095714.926789-1-yukuai1@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-raid@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: cCh0CgAX5g5hVuBlFsMHFg--.11578S14 X-Coremail-Antispam: 1UD129KBjvJXoWxZF45XFW8tF4kGF4kuFy8Krg_yoW5KFyDpa 1avwn3XrWkXr9xu3y3Jr4UCryS9w1fJF48GFZ7A34FgrySqrWUta18KrW3Zr97J393J34U X3Z3GrW7C3WkCrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPI14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVW8JVW5JwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr 0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUQ SdkUUUUU= X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ From: Yu Kuai There is no functional change for now, make read_balance() cleaner and prepare to fix problems and refactor the handler of sequential IO. Co-developed-by: Paul Luse Signed-off-by: Paul Luse Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni --- drivers/md/raid1.c | 71 ++++++++++++++++++++++++---------------------- 1 file changed, 37 insertions(+), 34 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index f6e75c123e5a..17c2201d5d2b 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -705,6 +705,31 @@ static int choose_slow_rdev(struct r1conf *conf, struct r1bio *r1_bio, return bb_disk; } +static bool is_sequential(struct r1conf *conf, int disk, struct r1bio *r1_bio) +{ + /* TODO: address issues with this check and concurrency. */ + return conf->mirrors[disk].next_seq_sect == r1_bio->sector || + conf->mirrors[disk].head_position == r1_bio->sector; +} + +/* + * If buffered sequential IO size exceeds optimal iosize, check if there is idle + * disk. If yes, choose the idle disk. + */ +static bool should_choose_next(struct r1conf *conf, int disk) +{ + struct raid1_info *mirror = &conf->mirrors[disk]; + int opt_iosize; + + if (!test_bit(Nonrot, &mirror->rdev->flags)) + return false; + + opt_iosize = bdev_io_opt(mirror->rdev->bdev) >> 9; + return opt_iosize > 0 && mirror->seq_start != MaxSector && + mirror->next_seq_sect > opt_iosize && + mirror->next_seq_sect - opt_iosize >= mirror->seq_start; +} + /* * This routine returns the disk from which the requested read should * be done. There is a per-array 'next expected sequential IO' sector @@ -768,43 +793,21 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect pending = atomic_read(&rdev->nr_pending); dist = abs(this_sector - conf->mirrors[disk].head_position); /* Don't change to another disk for sequential reads */ - if (conf->mirrors[disk].next_seq_sect == this_sector - || dist == 0) { - int opt_iosize = bdev_io_opt(rdev->bdev) >> 9; - struct raid1_info *mirror = &conf->mirrors[disk]; - - /* - * If buffered sequential IO size exceeds optimal - * iosize, check if there is idle disk. If yes, choose - * the idle disk. read_balance could already choose an - * idle disk before noticing it's a sequential IO in - * this disk. This doesn't matter because this disk - * will idle, next time it will be utilized after the - * first disk has IO size exceeds optimal iosize. In - * this way, iosize of the first disk will be optimal - * iosize at least. iosize of the second disk might be - * small, but not a big deal since when the second disk - * starts IO, the first disk is likely still busy. - */ - if (test_bit(Nonrot, &rdev->flags) && opt_iosize > 0 && - mirror->seq_start != MaxSector && - mirror->next_seq_sect > opt_iosize && - mirror->next_seq_sect - opt_iosize >= - mirror->seq_start) { - /* - * Add 'pending' to avoid choosing this disk if - * there is other idle disk. - */ - pending++; - /* - * If there is no other idle disk, this disk - * will be chosen. - */ - sequential_disk = disk; - } else { + if (is_sequential(conf, disk, r1_bio)) { + if (!should_choose_next(conf, disk)) { best_disk = disk; break; } + /* + * Add 'pending' to avoid choosing this disk if + * there is other idle disk. + */ + pending++; + /* + * If there is no other idle disk, this disk + * will be chosen. + */ + sequential_disk = disk; } if (min_pending > pending) {