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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFE8CC433FE for ; Sat, 19 Feb 2022 03:02:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241240AbiBSDDB (ORCPT ); Fri, 18 Feb 2022 22:03:01 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:50936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241235AbiBSDC7 (ORCPT ); Fri, 18 Feb 2022 22:02:59 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 874B9109A76; Fri, 18 Feb 2022 19:02:38 -0800 (PST) Received: from dggeme756-chm.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4K0tcm53vwzdZMM; Sat, 19 Feb 2022 11:01:28 +0800 (CST) Received: from [10.174.176.103] (10.174.176.103) 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; Sat, 19 Feb 2022 11:02:36 +0800 Message-ID: <52ed098e-db59-f20e-6536-bef48d473317@huawei.com> Date: Sat, 19 Feb 2022 11:02:36 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Subject: Re: [PATCH -next v2] block: update io_ticks when io hang From: "zhangwensheng (E)" To: CC: , References: <20220217064247.4041435-1-zhangwensheng5@huawei.com> In-Reply-To: <20220217064247.4041435-1-zhangwensheng5@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.103] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggeme756-chm.china.huawei.com (10.3.19.102) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org friendly ping... 在 2022/2/17 14:42, Zhang Wensheng 写道: > 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 "