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 B8A7FC77B6E for ; Thu, 13 Apr 2023 15:56:20 +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 1pmzJ6-0000i6-Ur; Thu, 13 Apr 2023 15:56:20 +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 1pmzJ5-0000i0-U7 for linux-f2fs-devel@lists.sourceforge.net; Thu, 13 Apr 2023 15:56:19 +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=ZKMymnsHzzvtAWJBhDLgE92UHvxzXWzQiZwEiEk6HMA=; b=YEujCQbbFYO4OrXKo+h28IprYr ggKjgBzTgZ/r85ReO7/Ex6CU7wf+kP+J9CHIjewTFd03Bs4EDYji6RAVYJTOhl8JZVh28LcrhyfBH 3OW0LJyvMMG60vlVPmjBmJuog6RyjREpRJXLfA+AWaH0JHLRU3CAsqYTTOG3ePRFCR54=; 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=ZKMymnsHzzvtAWJBhDLgE92UHvxzXWzQiZwEiEk6HMA=; b=EVWEzfs1oi+Niv16WqVlzzAa+l Ub90VSDePAlI3WGFGiGRTqbPCus+GE03XsQPbq5rc5m2m6HXgMnw5rI5pafVtopMtYkDjH+FRwAXc Ls4VGSxbn+dMOUFfbk/EpkUc9piSPwhC5bBl/E6E5nZPydvNv2qexhKIio7Jp72+cwBQ=; Received: from dfw.source.kernel.org ([139.178.84.217]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1pmzJ3-0006e6-UL for linux-f2fs-devel@lists.sourceforge.net; Thu, 13 Apr 2023 15:56:18 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 81D6C6166F for ; Thu, 13 Apr 2023 15:56:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBCC2C433D2; Thu, 13 Apr 2023 15:56:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681401371; bh=y9HpfTYL9kBGW9nfkCYmmN01yB0vDwslZmn1dH6LDMM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VqE64g/PJEYVfQcBGeksGFjuR3EvZPwS/EinIsxQcsfBM73rq4Th93YsTxznoEmnf su+xOrU4DV5cICXTolbQWoOAwqgq92uVM9rRpp9qc85CGr1GvPP8MB2pa38oZYJSiM 4nq7qo3KWtCgIkcAEnVGiNB0BYJ0xADoEOfeqph8sSpbUEesLv3nvNzFFr0n6sB0Xo l1aQyofDq+4l6EQ41OMwLQA5vp8GeO6EGQleRwBOyjUToOGxk6vUrGOU6ExXT43YBo McGa8gRj5ByUvaiY7d8Of6dGOhApDw2cTXsxw2MVD7sS8CqJpiUFX69sFbQ5VShy8g yNaK7zq1A+69w== Date: Thu, 13 Apr 2023 08:56:10 -0700 From: Jaegeuk Kim To: Chao Yu Message-ID: References: <20230324071028.336982-1-chao@kernel.org> <6c9abd05-297a-ea4f-fd5c-9f4d9fb488ab@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <6c9abd05-297a-ea4f-fd5c-9f4d9fb488ab@kernel.org> X-Headers-End: 1pmzJ3-0006e6-UL Subject: Re: [f2fs-dev] [PATCH] f2fs: fix to trigger a checkpoint in the end of foreground garbage collection 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 04/13, Chao Yu wrote: > On 2023/4/11 7:21, Jaegeuk Kim wrote: > > On 04/10, Chao Yu wrote: > > > On 2023/4/5 23:55, Jaegeuk Kim wrote: > > > > On 04/05, Chao Yu wrote: > > > > > On 2023/4/5 5:39, Jaegeuk Kim wrote: > > > > > > Can we do like this? > > > > > > > > > > > > From 9a58f0e59364241aa31b555cfe793d278e39b0dc Mon Sep 17 00:00:00 2001 > > > > > > From: Jaegeuk Kim > > > > > > Date: Tue, 4 Apr 2023 14:36:00 -0700 > > > > > > Subject: [PATCH] f2fs: do checkpoint when there's not enough free sections > > > > > > > > > > > > We didn't do checkpoint in FG_GC case, which may cause losing to reclaim prefree > > > > > > sctions in time. > > > > > > > > > > > > Fixes: 6f8d4455060d ("f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc") > > > > > > Signed-off-by: Chao Yu > > > > > > Signed-off-by: Jaegeuk Kim > > > > > > --- > > > > > > fs/f2fs/gc.c | 24 +++++++++++------------- > > > > > > 1 file changed, 11 insertions(+), 13 deletions(-) > > > > > > > > > > > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > > > > > > index 56c53dbe05c9..f1d0dd9c5a6c 100644 > > > > > > --- a/fs/f2fs/gc.c > > > > > > +++ b/fs/f2fs/gc.c > > > > > > @@ -1806,6 +1806,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > > > > > }; > > > > > > unsigned int skipped_round = 0, round = 0; > > > > > > unsigned int upper_secs; > > > > > > + bool stop_gc = false; > > > > > > trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc, > > > > > > gc_control->nr_free_secs, > > > > > > @@ -1876,19 +1877,15 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > > > > > (gc_type == FG_GC) ? sec_freed : 0, 0)) { > > > > > > if (gc_type == FG_GC && sec_freed < gc_control->nr_free_secs) > > > > > > goto go_gc_more; > > > > > > - goto stop; > > > > > > - } > > > > > > - > > > > > > - /* FG_GC stops GC by skip_count */ > > > > > > - if (gc_type == FG_GC) { > > > > > > + stop_gc = true; > > > > > > > > > > I guess below condition is for emergency recycle of prefree segments during > > > > > foreground GC, in order to avoid exhausting free sections due to to many > > > > > metadata allocation during CP. > > > > > > > > > > if (free_sections(sbi) <= upper_secs + NR_GC_CHECKPOINT_SECS && > > > > > prefree_segments(sbi)) { > > > > > > > > > > But for common case, free_sections() is close to reserved_segments(), and > > > > > upper_secs + NR_GC_CHECKPOINT_SECS value may be far smaller than free_sections(), > > > > > so checkpoint may not be trggered as expected, IIUC. > > > > > > > > > > So it's fine to just trigger CP in the end of foreground garbage collection? > > > > > > > > My major concern is to avoid unnecessary checkpointing given multiple FG_GC > > > > requests were pending in parallel. And, I don't want to add so many combination > > > > which gives so many corner cases, and feel f2fs_gc() needs to call checkpoint > > > > automatically in the worst case scenario only. > > > > > > Alright. > > > > > > > > > > > By the way, do we just need to call checkpoint here including FG_GC as well? > > > > > > I didn't get it, do you mean? > > > > > > - f2fs_balance_fs() > > > - f2fs_gc() creates prefree segments but not call checkpoint to reclaim > > > > > > - f2fs_balance_fs() > > > - f2fs_gc() > > > - detect prefree segments created by last f2fs_balance_fs, then call > > > f2fs_write_checkpoint to reclaim > > > > > > Or could you please provide a draft patch? :-P > > > > Testing this. > > > > From ec5f37bbe33110257c04e0ec97a80b0111465b52 Mon Sep 17 00:00:00 2001 > > From: Jaegeuk Kim > > Date: Mon, 10 Apr 2023 14:48:50 -0700 > > Subject: [PATCH] f2fs: refactor f2fs_gc to call checkpoint in urgent condition > > > > The major change is to call checkpoint, if there's not enough space while having > > some prefree segments in FG_GC case. > > I found generic/269 will hang w/ this patch. Yeah, I got 270 as well. I removed it in the tree first, and will check it out later. > > Thanks, > > > > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/gc.c | 26 ++++++++++++-------------- > > 1 file changed, 12 insertions(+), 14 deletions(-) > > > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > > index c748cdfb0501..0a823d2e8b9d 100644 > > --- a/fs/f2fs/gc.c > > +++ b/fs/f2fs/gc.c > > @@ -1829,7 +1829,10 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > goto stop; > > } > > - if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) { > > + /* Let's run FG_GC, if we don't have enough space. */ > > + if (has_not_enough_free_secs(sbi, 0, 0)) { > > + gc_type = FG_GC; > > + > > /* > > * For example, if there are many prefree_segments below given > > * threshold, we can make them free by checkpoint. Then, we > > @@ -1840,8 +1843,6 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > if (ret) > > goto stop; > > } > > - if (has_not_enough_free_secs(sbi, 0, 0)) > > - gc_type = FG_GC; > > } > > /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */ > > @@ -1868,19 +1869,14 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno)) > > sec_freed++; > > - if (gc_type == FG_GC) > > + if (gc_type == FG_GC) { > > sbi->cur_victim_sec = NULL_SEGNO; > > - if (gc_control->init_gc_type == FG_GC || > > - !has_not_enough_free_secs(sbi, > > - (gc_type == FG_GC) ? sec_freed : 0, 0)) { > > - if (gc_type == FG_GC && sec_freed < gc_control->nr_free_secs) > > - goto go_gc_more; > > - goto stop; > > - } > > - > > - /* FG_GC stops GC by skip_count */ > > - if (gc_type == FG_GC) { > > + if (!has_not_enough_free_secs(sbi, sec_freed, 0)) { > > + if (sec_freed < gc_control->nr_free_secs) > > + goto go_gc_more; > > + goto stop; > > + } > > if (sbi->skipped_gc_rwsem) > > skipped_round++; > > round++; > > @@ -1889,6 +1885,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > ret = f2fs_write_checkpoint(sbi, &cpc); > > goto stop; > > } > > + } else if (!has_not_enough_free_secs(sbi, 0, 0)) { > > + goto stop; > > } > > __get_secs_required(sbi, NULL, &upper_secs, NULL); _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel