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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1ED43C433EF for ; Wed, 11 May 2022 16:48:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344954AbiEKQr7 (ORCPT ); Wed, 11 May 2022 12:47:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233496AbiEKQrx (ORCPT ); Wed, 11 May 2022 12:47:53 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C46956B7DB for ; Wed, 11 May 2022 09:47:51 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 548A8B825C6 for ; Wed, 11 May 2022 16:47:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01B9BC340EE; Wed, 11 May 2022 16:47:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652287669; bh=QV99+jPkDYyME6XjoOoBh86aocJlMkd03PUpuxghXhg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=d3sl9dOocU/YK6sMmndolIRFpxJwqf/LFrkAdlgcyV06pzsCuo5ymAevGwHKPmytP Q57XCI6TGrqIfLwZ0w7MZQBKNxk1kdo/VPl7V1BCD9I54f7oM2P6/GtyrYNprK8Spe Cde0RiHXp+YlCDXOSPRnp40ZdmGMlyQvxM1K6YfkkkIQ4dhK114q2lZDmaAf0LGsvw MbJC9didHWeL/w1TEvbDeJ8039ZE9n0Vv8nYFJzPyGYYkZ8txi8Q8l8/6a01fXw+l9 YcayFT/rh6KD/7GeIyj4j0mv+z8sNYNLbqi6gUciNGwRdHPxz9M+oPaUJBTHNBFy9C Ix8c2aYpfTcKQ== Date: Wed, 11 May 2022 09:47:47 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH 4/5] f2fs: do not stop GC when requiring a free section Message-ID: References: <20220506232032.1264078-1-jaegeuk@kernel.org> <20220506232032.1264078-4-jaegeuk@kernel.org> <77e870dd-fd7a-f58e-79fb-d0e5b8fbfc16@kernel.org> <42c23c83-1914-e8dd-c765-df3d6d872532@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42c23c83-1914-e8dd-c765-df3d6d872532@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/11, Chao Yu wrote: > On 2022/5/10 0:55, Jaegeuk Kim wrote: > > On 05/08, Chao Yu wrote: > > > On 2022/5/7 7:20, Jaegeuk Kim wrote: > > > > The f2fs_gc uses a bitmap to indicate pinned sections, but when disabling > > > > chckpoint, we call f2fs_gc() with NULL_SEGNO which selects the same dirty > > > > segment as a victim all the time, resulting in checkpoint=disable failure, > > > > for example. Let's pick another one, if we fail to collect it. > > > > > > > > Signed-off-by: Jaegeuk Kim > > > > --- > > > > fs/f2fs/f2fs.h | 1 + > > > > fs/f2fs/file.c | 12 ++++++++---- > > > > fs/f2fs/gc.c | 11 +++++++---- > > > > fs/f2fs/segment.c | 3 ++- > > > > fs/f2fs/super.c | 3 ++- > > > > include/trace/events/f2fs.h | 11 ++++++++--- > > > > 6 files changed, 28 insertions(+), 13 deletions(-) > > > > > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > > > index d49b9b476592..27871f6efb01 100644 > > > > --- a/fs/f2fs/f2fs.h > > > > +++ b/fs/f2fs/f2fs.h > > > > @@ -1282,6 +1282,7 @@ struct f2fs_gc_control { > > > > bool no_bg_gc; /* check the space and stop bg_gc */ > > > > bool should_migrate_blocks; /* should migrate blocks */ > > > > bool err_gc_skipped; /* return EAGAIN if GC skipped */ > > > > + unsigned int nr_free_secs; /* # of free sections to do GC */ > > > > }; > > > > /* For s_flag in struct f2fs_sb_info */ > > > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > > > index 0e7d101c3e65..7072c2b86b2f 100644 > > > > --- a/fs/f2fs/file.c > > > > +++ b/fs/f2fs/file.c > > > > @@ -1650,7 +1650,8 @@ static int expand_inode_data(struct inode *inode, loff_t offset, > > > > struct f2fs_gc_control gc_control = { .victim_segno = NULL_SEGNO, > > > > .init_gc_type = FG_GC, > > > > .should_migrate_blocks = false, > > > > - .err_gc_skipped = true }; > > > > + .err_gc_skipped = true, > > > > + .nr_free_secs = 0 }; > > > > pgoff_t pg_start, pg_end; > > > > loff_t new_size = i_size_read(inode); > > > > loff_t off_end; > > > > @@ -2453,7 +2454,8 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg) > > > > struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > > > > struct f2fs_gc_control gc_control = { .victim_segno = NULL_SEGNO, > > > > .no_bg_gc = false, > > > > - .should_migrate_blocks = false }; > > > > + .should_migrate_blocks = false, > > > > + .nr_free_secs = 0 }; > > > > __u32 sync; > > > > int ret; > > > > @@ -2494,7 +2496,8 @@ static int __f2fs_ioc_gc_range(struct file *filp, struct f2fs_gc_range *range) > > > > .init_gc_type = range->sync ? FG_GC : BG_GC, > > > > .no_bg_gc = false, > > > > .should_migrate_blocks = false, > > > > - .err_gc_skipped = range->sync }; > > > > + .err_gc_skipped = range->sync, > > > > + .nr_free_secs = 0 }; > > > > u64 end; > > > > int ret; > > > > @@ -2940,7 +2943,8 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg) > > > > struct f2fs_gc_control gc_control = { > > > > .init_gc_type = FG_GC, > > > > .should_migrate_blocks = true, > > > > - .err_gc_skipped = true }; > > > > + .err_gc_skipped = true, > > > > + .nr_free_secs = 0 }; > > > > int ret; > > > > if (!capable(CAP_SYS_ADMIN)) > > > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > > > > index ec3f6f876e76..f63576ff1c2d 100644 > > > > --- a/fs/f2fs/gc.c > > > > +++ b/fs/f2fs/gc.c > > > > @@ -147,6 +147,7 @@ static int gc_thread_func(void *data) > > > > gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC; > > > > gc_control.no_bg_gc = foreground; > > > > + gc_control.nr_free_secs = foreground ? 1 : 0; > > > > > > if init_gc_type is BG_GC, sec_freed won't increase for background GC due to > > > below statement: > > > > > > if (gc_type == FG_GC && > > > get_valid_blocks(sbi, segno, false) == 0) > > > seg_freed++; > > > > > > It may cause gc thread migrates lots of segments in each round? > > > > BG_GC include two cases, f2fs_balance_fs and gc thread for GC_MERGE, both of > > which are no_bg_gc=true. So, I think this would be enough. Other cases that sets > > nr_free_secs to 1 should be FG_GC only. > > What I mean is, in below check condition, for BG_GC cases, > if !has_not_enough_free_secs(sbi, sec_freed, 0) is true, since sec_freed will > never be increased due to above condition, so it will goto gc_more label all > the time, result in looping until migrating all dirty segments. I mean gc_control->nr_free_secs should be 0. > > Thanks, > > > > > > > > > if ((gc_control->init_gc_type == FG_GC || > > > !has_not_enough_free_secs(sbi, sec_freed, 0))) { > > > if (sec_freed < gc_control->nr_free_secs) > > > goto gc_more; > > > goto stop; > > > } > > > > > > > /* if return value is not zero, no victim was selected */ > > > > if (f2fs_gc(sbi, &gc_control)) > > > > @@ -1776,6 +1777,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > > > unsigned int skipped_round = 0, round = 0; > > > > trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc, > > > > + gc_control->nr_free_secs, > > > > get_pages(sbi, F2FS_DIRTY_NODES), > > > > get_pages(sbi, F2FS_DIRTY_DENTS), > > > > get_pages(sbi, F2FS_DIRTY_IMETA), > > > > @@ -1848,11 +1850,12 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) > > > > if (gc_type == FG_GC) > > > > sbi->cur_victim_sec = NULL_SEGNO; > > > > - if (gc_control->init_gc_type == FG_GC) > > > > - goto stop; > > > > - > > > > - if (!has_not_enough_free_secs(sbi, sec_freed, 0)) > > > > + if ((gc_control->init_gc_type == FG_GC || > > > > + !has_not_enough_free_secs(sbi, sec_freed, 0))) { > > > > + if (sec_freed < gc_control->nr_free_secs) > > > > + goto gc_more; > > > > goto stop; > > > > + } > > > > if (skipped_round <= MAX_SKIP_GC_COUNT || skipped_round * 2 < round) { > > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > > > > index bc63f0572c64..d6b9231ab0e1 100644 > > > > --- a/fs/f2fs/segment.c > > > > +++ b/fs/f2fs/segment.c > > > > @@ -528,7 +528,8 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need) > > > > .init_gc_type = BG_GC, > > > > .no_bg_gc = true, > > > > .should_migrate_blocks = false, > > > > - .err_gc_skipped = false }; > > > > + .err_gc_skipped = false, > > > > + .nr_free_secs = 1 }; > > > > > > .init_gc_type is BG_GC, so !has_not_enough_free_secs(sbi, sec_freed, 0) condition > > > should be enough to exit? > > > > > > if ((gc_control->init_gc_type == FG_GC || > > > !has_not_enough_free_secs(sbi, sec_freed, 0))) { > > > if (sec_freed < gc_control->nr_free_secs) > > > goto gc_more; > > > goto stop; > > > } > > > > > > Thanks, > > > > > > > f2fs_down_write(&sbi->gc_lock); > > > > f2fs_gc(sbi, &gc_control); > > > > } > > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > > > > index 8b23fa6fc6b7..5d5b35067c3d 100644 > > > > --- a/fs/f2fs/super.c > > > > +++ b/fs/f2fs/super.c > > > > @@ -2084,7 +2084,8 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) > > > > .victim_segno = NULL_SEGNO, > > > > .init_gc_type = FG_GC, > > > > .should_migrate_blocks = false, > > > > - .err_gc_skipped = true }; > > > > + .err_gc_skipped = true, > > > > + .nr_free_secs = 1 }; > > > > f2fs_down_write(&sbi->gc_lock); > > > > err = f2fs_gc(sbi, &gc_control); > > > > diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h > > > > index 6699174977a3..349679a72301 100644 > > > > --- a/include/trace/events/f2fs.h > > > > +++ b/include/trace/events/f2fs.h > > > > @@ -653,18 +653,21 @@ TRACE_EVENT(f2fs_background_gc, > > > > TRACE_EVENT(f2fs_gc_begin, > > > > TP_PROTO(struct super_block *sb, int gc_type, bool no_bg_gc, > > > > + unsigned int nr_free_secs, > > > > long long dirty_nodes, long long dirty_dents, > > > > long long dirty_imeta, unsigned int free_sec, > > > > unsigned int free_seg, int reserved_seg, > > > > unsigned int prefree_seg), > > > > - TP_ARGS(sb, gc_type, no_bg_gc, dirty_nodes, dirty_dents, dirty_imeta, > > > > + TP_ARGS(sb, gc_type, no_bg_gc, nr_free_secs, dirty_nodes, > > > > + dirty_dents, dirty_imeta, > > > > free_sec, free_seg, reserved_seg, prefree_seg), > > > > TP_STRUCT__entry( > > > > __field(dev_t, dev) > > > > __field(int, gc_type) > > > > __field(bool, no_bg_gc) > > > > + __field(unsigned int, nr_free_secs) > > > > __field(long long, dirty_nodes) > > > > __field(long long, dirty_dents) > > > > __field(long long, dirty_imeta) > > > > @@ -678,6 +681,7 @@ TRACE_EVENT(f2fs_gc_begin, > > > > __entry->dev = sb->s_dev; > > > > __entry->gc_type = gc_type; > > > > __entry->no_bg_gc = no_bg_gc; > > > > + __entry->nr_free_secs = nr_free_secs; > > > > __entry->dirty_nodes = dirty_nodes; > > > > __entry->dirty_dents = dirty_dents; > > > > __entry->dirty_imeta = dirty_imeta; > > > > @@ -687,12 +691,13 @@ TRACE_EVENT(f2fs_gc_begin, > > > > __entry->prefree_seg = prefree_seg; > > > > ), > > > > - TP_printk("dev = (%d,%d), gc_type = %s, no_background_GC = %d, nodes = %lld, " > > > > - "dents = %lld, imeta = %lld, free_sec:%u, free_seg:%u, " > > > > + TP_printk("dev = (%d,%d), gc_type = %s, no_background_GC = %d, nr_free_secs = %u, " > > > > + "nodes = %lld, dents = %lld, imeta = %lld, free_sec:%u, free_seg:%u, " > > > > "rsv_seg:%d, prefree_seg:%u", > > > > show_dev(__entry->dev), > > > > show_gc_type(__entry->gc_type), > > > > __entry->no_bg_gc, > > > > + __entry->nr_free_secs, > > > > __entry->dirty_nodes, > > > > __entry->dirty_dents, > > > > __entry->dirty_imeta,