From patchwork Thu Feb 17 04:02:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Wensheng X-Patchwork-Id: 12749283 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 375F0C433EF for ; Thu, 17 Feb 2022 03:47:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229995AbiBQDrU (ORCPT ); Wed, 16 Feb 2022 22:47:20 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:38166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229831AbiBQDrS (ORCPT ); Wed, 16 Feb 2022 22:47:18 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5501EC0506; Wed, 16 Feb 2022 19:47:04 -0800 (PST) Received: from dggeme756-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Jzghz3n30zbnZq; Thu, 17 Feb 2022 11:45:55 +0800 (CST) Received: from localhost.localdomain (10.175.127.227) by dggeme756-chm.china.huawei.com (10.3.19.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.21; Thu, 17 Feb 2022 11:47:01 +0800 From: Zhang Wensheng To: , , Subject: [PATCH -next v2] block: update io_ticks when io hang Date: Thu, 17 Feb 2022 12:02:45 +0800 Message-ID: <20220217040245.3886752-1-zhangwensheng5@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggeme756-chm.china.huawei.com (10.3.19.102) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org When the inflight IOs are slow and no new IOs are issued, we expect iostat could manifest the IO hang problem. However after commit 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting"), io_tick and time_in_queue will not be updated until the end of IO, and the avgqu-sz and %util columns of iostat will be zero. Because it has using stat.nsecs accumulation to express time_in_queue which is not suitable to change, and may %util will express the status better when io hang occur. To fix io_ticks, we use update_io_ticks and inflight to update io_ticks when diskstats_show and part_stat_show been called. Fixes: 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting") Signed-off-by: Zhang Wensheng --- block/genhd.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- v2: * add part_stat_lock() & part_stat_unlock() to protect update_io_ticks(). v1: https://www.spinics.net/lists/linux-block/msg78931.html diff --git a/block/genhd.c b/block/genhd.c index 626c8406f21a..781dc78f97d8 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -913,12 +913,17 @@ ssize_t part_stat_show(struct device *dev, struct disk_stats stat; unsigned int inflight; - part_stat_read_all(bdev, &stat); if (queue_is_mq(q)) inflight = blk_mq_in_flight(q, bdev); else inflight = part_in_flight(bdev); + if (inflight) { + part_stat_lock(); + update_io_ticks(bdev, jiffies, true); + part_stat_unlock(); + } + part_stat_read_all(bdev, &stat); return sprintf(buf, "%8lu %8lu %8llu %8u " "%8lu %8lu %8llu %8u " @@ -1174,12 +1179,17 @@ static int diskstats_show(struct seq_file *seqf, void *v) xa_for_each(&gp->part_tbl, idx, hd) { if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) continue; - part_stat_read_all(hd, &stat); if (queue_is_mq(gp->queue)) inflight = blk_mq_in_flight(gp->queue, hd); else inflight = part_in_flight(hd); + if (inflight) { + part_stat_lock(); + update_io_ticks(hd, jiffies, true); + part_stat_unlock(); + } + part_stat_read_all(hd, &stat); seq_printf(seqf, "%4d %7d %pg " "%lu %lu %lu %u " "%lu %lu %lu %u "