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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 EE956C433ED for ; Tue, 6 Apr 2021 09:09:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C44676139C for ; Tue, 6 Apr 2021 09:09:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240655AbhDFJJx (ORCPT ); Tue, 6 Apr 2021 05:09:53 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:64570 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233626AbhDFJJo (ORCPT ); Tue, 6 Apr 2021 05:09:44 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1617700173; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=F4jdbffDeZDNKhypu4nbWbPE4bfUYUk0a5UryZXysDE=; b=Iwu+Ro1lRqaealaSfacsMl5UVB0nTjYpoqS0JVZfyChIxRRGycdsYzeV1hi2u7CskKqGmf5i oFbL83gDRkcB+6d9NKjvbcnbUOZ3m7X3V8+MoTfJIo4xYpORCi3Hjn73kMIp96rqOW5T06PB D6Y19wzlA02SEuGN3aocaPcLdtY= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-east-1.postgun.com with SMTP id 606c254cc06dd10a2d3fbeb2 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 06 Apr 2021 09:09:32 GMT Sender: stummala=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 0D61EC433C6; Tue, 6 Apr 2021 09:09:32 +0000 (UTC) Received: from codeaurora.org (unknown [202.46.22.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: stummala) by smtp.codeaurora.org (Postfix) with ESMTPSA id 44B04C43463; Tue, 6 Apr 2021 09:09:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 44B04C43463 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=stummala@codeaurora.org From: Sahitya Tummala To: Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net Cc: Sahitya Tummala , linux-kernel@vger.kernel.org Subject: [PATCH v2] f2fs: fix the periodic wakeups of discard thread Date: Tue, 6 Apr 2021 14:39:16 +0530 Message-Id: <1617700156-19719-1-git-send-email-stummala@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <20210316093406.GC8562@codeaurora.org> References: <20210316093406.GC8562@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix the unnecessary periodic wakeups of discard thread that happens under below two conditions - 1. When f2fs is heavily utilized over 80%, the current discard policy sets the max sleep timeout of discard thread as 50ms (DEF_MIN_DISCARD_ISSUE_TIME). But this is set even when there are no pending discard commands to be issued. 2. In the issue_discard_thread() path when there are no pending discard commands, it fails to reset the wait_ms to max timeout value. Signed-off-by: Sahitya Tummala --- v2: - Fix the second scenario mentioned above in commit text fs/f2fs/segment.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index d7076796..59efec5 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -1112,6 +1112,8 @@ static void __init_discard_policy(struct f2fs_sb_info *sbi, struct discard_policy *dpolicy, int discard_type, unsigned int granularity) { + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info; + /* common policy */ dpolicy->type = discard_type; dpolicy->sync = true; @@ -1131,7 +1133,9 @@ static void __init_discard_policy(struct f2fs_sb_info *sbi, dpolicy->ordered = true; if (utilization(sbi) > DEF_DISCARD_URGENT_UTIL) { dpolicy->granularity = 1; - dpolicy->max_interval = DEF_MIN_DISCARD_ISSUE_TIME; + if (atomic_read(&dcc->discard_cmd_cnt)) + dpolicy->max_interval = + DEF_MIN_DISCARD_ISSUE_TIME; } } else if (discard_type == DPOLICY_FORCE) { dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME; @@ -1747,8 +1751,15 @@ static int issue_discard_thread(void *data) set_freezable(); do { - __init_discard_policy(sbi, &dpolicy, DPOLICY_BG, - dcc->discard_granularity); + if (sbi->gc_mode == GC_URGENT_HIGH || + !f2fs_available_free_memory(sbi, DISCARD_CACHE)) + __init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1); + else + __init_discard_policy(sbi, &dpolicy, DPOLICY_BG, + dcc->discard_granularity); + + if (!atomic_read(&dcc->discard_cmd_cnt)) + wait_ms = dpolicy.max_interval; wait_event_interruptible_timeout(*q, kthread_should_stop() || freezing(current) || @@ -1775,10 +1786,6 @@ static int issue_discard_thread(void *data) if (!atomic_read(&dcc->discard_cmd_cnt)) continue; - if (sbi->gc_mode == GC_URGENT_HIGH || - !f2fs_available_free_memory(sbi, DISCARD_CACHE)) - __init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1); - sb_start_intwrite(sbi->sb); issued = __issue_discard_cmd(sbi, &dpolicy); -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.