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 4AC5BC77B61 for ; Thu, 13 Apr 2023 09:15:59 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1pmt3c-0008OG-Rg; Thu, 13 Apr 2023 09:15:57 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pmt3b-0008Ns-Hd for linux-f2fs-devel@lists.sourceforge.net; Thu, 13 Apr 2023 09:15:55 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: 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=CcIo6Ibh1NoQkBmW0ILLk8sApm9b0+vkYgQMR+cgeYM=; b=IMmItXjXDxBzRTidMS2gzDqTju vxYNP2zihrE0mxBvk17JOCuKuhW7e5n5YR19O0Zef949MtnTnAXs3dBInkSVomOI/hH/JmY0i5q45 Rs2YHEKFCBatesCUYo3fYMoU7XdgKCCwYUhEnkfOdUvcUUr625qAjsCtCvRy7KF5Ahzs=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: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=CcIo6Ibh1NoQkBmW0ILLk8sApm9b0+vkYgQMR+cgeYM=; b=L+NfHvtv5Vz0eq3DFv1sieB477 nZRUX01pDQXhvKB3rQ5UUlXyoX9RpaXaZ79rQuCb+nfWWGEDBauuurh+v4rkCCCfYUTB3pMkbpvXT ti5jRchBCNp2jMqdOc2aENMWcMoTQImsWXw2J/DfVe3ttiGWa9poqUaL8XfFjYMVf8ZI=; 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 1pmt3b-0008O6-0U for linux-f2fs-devel@lists.sourceforge.net; Thu, 13 Apr 2023 09:15:55 +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 946B463CCA for ; Thu, 13 Apr 2023 09:15:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45994C433D2; Thu, 13 Apr 2023 09:15:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681377349; bh=yvu+LldXJrLBPxrSdY63YC5/guSRhjJdIzg4/OHP/P0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=OyNeI8+5L8xkAbYU6xSKs0OaSv8rdj0nKzfMPpxHo8cBA5HJ1tCedu2eleeoxcYaY 0UffZNl+ycUA4bhyM+bD4X2lB7vVfOMYq1R+Am/ekQBeL/Ocr6uteqbVJ6ARAvCjqK XfTmz8q2EhXDQb1ST4oxUltjO79NaNNoAkxA7nGZX/1a0dI8cDw2jSwXeUEEBObSUe E0yKQ3/FDJP3Z09Ij+qDOql5lsfeCZmad8qpsCiO+ZIafM2rwG0BzmXFY3QPQElCMa MQQ5TeZxjOSbhJGth5WUqnnBnwqdZ2BaTTuMeDSwo1wncrAtwxs+7Hno0xuKbRY0NR 8Yo2kU+Ze1vmQ== Message-ID: <6c9abd05-297a-ea4f-fd5c-9f4d9fb488ab@kernel.org> Date: Thu, 13 Apr 2023 17:15:46 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Content-Language: en-US To: Jaegeuk Kim References: <20230324071028.336982-1-chao@kernel.org> From: Chao Yu In-Reply-To: X-Headers-End: 1pmt3b-0008O6-0U 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net 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. 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