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 lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 57C27EB64D9 for ; Tue, 4 Jul 2023 10:53:26 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1qGdeq-00072b-LJ; Tue, 04 Jul 2023 10:53:21 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qGdel-00072R-Jh for linux-f2fs-devel@lists.sourceforge.net; Tue, 04 Jul 2023 10:53:16 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=In-Reply-To:Content-Type:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=/vdJu810T88gjWr0Pp0vyzm5kb4JMUb5SU9d9S62fLQ=; b=OZLOuPmPUbPE8fhkPzudxxz+ZX JGRNnwrXiFVtsx1TPfoi6ghzw2otupbQGgG7LDHpUKHkt9wU6xH3zCrNjDjJFeR4basmyBgCkBmAm QYJ4RZOFZnEOPWFfutVQwoXlq3p8eGYEDSXdukVKZjyJneiNLAD26p07YtTzzSY9QHrs=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To :From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=/vdJu810T88gjWr0Pp0vyzm5kb4JMUb5SU9d9S62fLQ=; b=nTUvEzZoDk+VUhf68sy5s3IPFi qNiFIhaib3VCum2M5ZH7cflMe1B8R+bclw715uZFJ87c4oWGR4E/UvARJO6b1fNxjRgZzS7UIEk3n lcMJeIRyg5ukvyqAZFgNOF2X3HWLifixx1iHqaL+wU0VLHfR1tQhcXGxx6X9/sk+tJMc=; Received: from dfw.source.kernel.org ([139.178.84.217]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1qGdei-005aAu-5j for linux-f2fs-devel@lists.sourceforge.net; Tue, 04 Jul 2023 10:53:16 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C1F8E611D3; Tue, 4 Jul 2023 10:53:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12DE0C433C7; Tue, 4 Jul 2023 10:53:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688467986; bh=die6ZmES6fy82wymKtHjkHnfAFbNdCjAo4pk5803uh0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YDTeWjlX0uF87RsqVfyyR7iW1vpr923L1RUUcpt3zHoVrnWZ6MeuhkUEgfv2DJwfO sEwXvWtCGAugJRpdMEEGR2LCGjUuAZskU+YFk8COvYIz6drfU+FWVDXlYFkCdcWw3r asGB5jrEY+sTpyoeBB+oZsdLs526ap81iiAa4dToCL1cOPBtyKsnYWCFl8g3ESOH5f tFZHkgB7qK1E1Iuxy1AkGZLxhY7C/KmATLtcwf1hwIkY/ahdW9R2itFkW3f49ywH8e Mpaydkm/yU8GPOad7FOx4T7PfD6oaVBqe/WGiaInGBrSuNoBXuaoNe1D4Zkzl1AyCj 4QJCvYZ+p//fw== Date: Tue, 4 Jul 2023 03:53:04 -0700 From: Jaegeuk Kim To: Chao Yu Message-ID: References: <20230613203947.2745943-1-jaegeuk@kernel.org> <50d5fa8c-4fe9-8a03-be78-0b5383e55b62@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <50d5fa8c-4fe9-8a03-be78-0b5383e55b62@kernel.org> X-Headers-End: 1qGdei-005aAu-5j Subject: Re: [f2fs-dev] [PATCH v2] f2fs: do not issue small discard commands during checkpoint X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On 07/03, Chao Yu wrote: > On 2023/6/15 0:10, Jaegeuk Kim wrote: > > If there're huge # of small discards, this will increase checkpoint latency > > insanely. Let's issue small discards only by trim. > > > > Signed-off-by: Jaegeuk Kim > > --- > > > > Change log from v1: > > - move the skip logic to avoid dangling objects > > > > fs/f2fs/segment.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > > index 8c7af8b4fc47..0457d620011f 100644 > > --- a/fs/f2fs/segment.c > > +++ b/fs/f2fs/segment.c > > @@ -2193,7 +2193,7 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi, > > len = next_pos - cur_pos; > > if (f2fs_sb_has_blkzoned(sbi) || > > - (force && len < cpc->trim_minlen)) > > + !force || len < cpc->trim_minlen) > > goto skip; > > Sorry for late reply. > > We have a configuration for such case, what do you think of setting > max_small_discards to zero? otherwise, w/ above change, max_small_discards > logic may be broken? > > What: /sys/fs/f2fs//max_small_discards > Date: November 2013 > Contact: "Jaegeuk Kim" > Description: Controls the issue rate of discard commands that consist of small > blocks less than 2MB. The candidates to be discarded are cached until > checkpoint is triggered, and issued during the checkpoint. > By default, it is disabled with 0. > > Or, if we prefer to disable small_discards by default, what about below change: I think small_discards is fine, but need to avoid long checkpoint latency only. > > From eb89d9b56e817e3046d7fa17165b12416f09d456 Mon Sep 17 00:00:00 2001 > From: Chao Yu > Date: Mon, 3 Jul 2023 09:06:53 +0800 > Subject: [PATCH] Revert "f2fs: enable small discard by default" > > This reverts commit d618ebaf0aa83d175658aea5291e0c459d471d39 in order > to disable small discard by default, so that if there're huge number of > small discards, it will decrease checkpoint's latency obviously. > > Also, this patch reverts 9ac00e7cef10 ("f2fs: do not issue small discard > commands during checkpoint"), due to it breaks small discard feature which > may be configured via sysfs entry max_small_discards. > > Fixes: 9ac00e7cef10 ("f2fs: do not issue small discard commands during checkpoint") > Signed-off-by: Chao Yu > --- > fs/f2fs/segment.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 14c822e5c9c9..0a313368f18b 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -2193,7 +2193,7 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi, > len = next_pos - cur_pos; > > if (f2fs_sb_has_blkzoned(sbi) || > - !force || len < cpc->trim_minlen) > + (force && len < cpc->trim_minlen)) > goto skip; > > f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos, > @@ -2269,7 +2269,7 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi) > atomic_set(&dcc->queued_discard, 0); > atomic_set(&dcc->discard_cmd_cnt, 0); > dcc->nr_discards = 0; > - dcc->max_discards = MAIN_SEGS(sbi) << sbi->log_blocks_per_seg; > + dcc->max_discards = 0; > dcc->max_discard_request = DEF_MAX_DISCARD_REQUEST; > dcc->min_discard_issue_time = DEF_MIN_DISCARD_ISSUE_TIME; > dcc->mid_discard_issue_time = DEF_MID_DISCARD_ISSUE_TIME; > -- > 2.40.1 > > > > > f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos, _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel