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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id C777FC4167B for ; Sun, 1 Jan 2023 07:18:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0E2708E0002; Sun, 1 Jan 2023 02:18:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0924A8E0001; Sun, 1 Jan 2023 02:18:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EC3AF8E0002; Sun, 1 Jan 2023 02:18:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id DD0568E0001 for ; Sun, 1 Jan 2023 02:18:31 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id AA26B1A053A for ; Sun, 1 Jan 2023 07:18:31 +0000 (UTC) X-FDA: 80305377222.22.34EAA39 Received: from r3-24.sinamail.sina.com.cn (r3-24.sinamail.sina.com.cn [202.108.3.24]) by imf25.hostedemail.com (Postfix) with ESMTP id 88292A0006 for ; Sun, 1 Jan 2023 07:18:27 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf25.hostedemail.com: domain of hdanton@sina.com designates 202.108.3.24 as permitted sender) smtp.mailfrom=hdanton@sina.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1672557509; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dMPggdSX+EFx1XLArvUnrzH/1v3vt40jEtN0oqwMep8=; b=gRPvMqkKGTmQSu3KFGAFZ8alXrgnJqa7FhBka/boYMcHkCwDd+Ri+plR6b/ddjsaxLlxdS aU5XRTJkAaC3wiRqMeeCtN7Fy8ZIwyTrO+8+SotCHtELItQXNdcnK3yBRG60nEQ4SrTq9b itAvCYOaEypHpDVMhVu0T7/Z3Jk5tro= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf25.hostedemail.com: domain of hdanton@sina.com designates 202.108.3.24 as permitted sender) smtp.mailfrom=hdanton@sina.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1672557509; a=rsa-sha256; cv=none; b=4RbygWhPKmzGgIVUcPm8JZK1Wm//4U0lXlm8dFu5Wj+HaF6vbhrDcRFr1/WNVi0Z3XvVWk AdNpZu0yHpSE4P0vHgqTNBukQbeu9Gu1jkKWGMXDPIXswEA5fNM9qcrfBe+SgXu6Fk6V6+ 2DCmlwS/b4rACRCsXcRrF69i/AenAJQ= Received: from unknown (HELO localhost.localdomain)([114.249.57.238]) by sina.com (172.16.97.23) with ESMTP id 63B133110002AE12; Sun, 1 Jan 2023 15:15:31 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com X-SMAIL-MID: 26060954919318 From: Hillf Danton To: Sergei Shtepa Cc: axboe@kernel.dk, corbet@lwn.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 17/21] block, blksnap: snapshot image block device Date: Sun, 1 Jan 2023 15:18:13 +0800 Message-Id: <20230101071813.3329-1-hdanton@sina.com> In-Reply-To: <20221209142331.26395-18-sergei.shtepa@veeam.com> References: <20221209142331.26395-1-sergei.shtepa@veeam.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 88292A0006 X-Stat-Signature: sffu5q6py6sgg9q4mkbyyzsu14ss9fzo X-Rspam-User: X-HE-Tag: 1672557507-835937 X-HE-Meta: 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 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: On 9 Dec 2022 15:23:27 +0100 Sergei Shtepa > Provides the operation of block devices of snapshot images. Read and > write operations are redirected to the regions of difference blocks for > block device (struct diff_area). > > Signed-off-by: Sergei Shtepa > --- Thanks for your patchset. > +static int snapimage_kthread_worker_fn(void *param) > +{ > + struct snapimage *snapimage = param; > + struct bio *bio; > + int ret = 0; > + > + while (!kthread_should_stop()) { > + bio = get_bio_from_queue(snapimage); > + if (!bio) { > + schedule_timeout_interruptible(HZ / 100); > + continue; > + } Given the wake_up_process() below, s$HZ / 100$HZ * 1000$ to avoid unnecessary wakeups [1]. And because of no signal handling added, use schedule_timeout_idle() instead. [1] https://lore.kernel.org/lkml/20210419085027.761150-2-elver@google.com/ > + > + snapimage_process_bio(snapimage, bio); > + } > + > + while ((bio = get_bio_from_queue(snapimage))) > + snapimage_process_bio(snapimage, bio); > + > + return ret; > +} > + > +static void snapimage_submit_bio(struct bio *bio) > +{ > + struct snapimage *snapimage = bio->bi_bdev->bd_disk->private_data; > + gfp_t gfp = GFP_NOIO; > + > + if (bio->bi_opf & REQ_NOWAIT) > + gfp |= GFP_NOWAIT; > + if (snapimage->is_ready) { > + spin_lock(&snapimage->queue_lock); > + bio_list_add(&snapimage->queue, bio); > + spin_unlock(&snapimage->queue_lock); > + > + wake_up_process(snapimage->worker); > + } else > + bio_io_error(bio); > +}