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 18A9AC433F5 for ; Tue, 17 May 2022 02:19:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238983AbiEQCTk (ORCPT ); Mon, 16 May 2022 22:19:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239488AbiEQCTe (ORCPT ); Mon, 16 May 2022 22:19:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62EB646672 for ; Mon, 16 May 2022 19:19:32 -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 E1111B816D6 for ; Tue, 17 May 2022 02:19:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9506AC385B8; Tue, 17 May 2022 02:19:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652753969; bh=xeelX37aefnabUdkKSV4ux4TQN82HYxRTKBDJaiRmmg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rgxWXfVqB63hCOCApyf9rB6ekVG6ILUT/frUPUTqVWFyK2aPh7vTABdU8OBnXDjYV i/2cLBFdlUxS8EIIy1cY8ny4jR0fS1+Nn0sn/sidjrrbywUTLYhGIWnULJJUsx3iCn PwDlfmq6YYvRsbYjTHMlQNjl6ZSPFnCOciFkPPCeJVPY7LLboNg09ag5t/xGiYtv+x lZ+o/3fv3tqNknpK8mOtLKtpX4ZSKc6B8+ZOxRKe7OyDoLbmyrchwsJsQ6xoysqpiB 0ro+cD2eafu4h8QCD+Rfskw2AtG4TxWLWb85gX/MvxW9poM/JL0ceAA26uAEG23Sy8 1ETlP6h1JRdLg== Message-ID: Date: Tue, 17 May 2022 10:19:25 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [f2fs-dev] [PATCH 4/5 v2] f2fs: do not stop GC when requiring a free section Content-Language: en-US To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net References: <20220506232032.1264078-1-jaegeuk@kernel.org> <20220506232032.1264078-4-jaegeuk@kernel.org> From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/5/17 1:29, Jaegeuk Kim wrote: > On 05/15, Chao Yu wrote: >> On 2022/5/13 4:50, 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 >>> --- >>> >>> Change log from v1: >>> - refactor the code path to avoid ambiguous condition like BG_GC/sec_freed >>> >>> fs/f2fs/f2fs.h | 1 + >>> fs/f2fs/file.c | 12 ++++++++---- >>> fs/f2fs/gc.c | 14 +++++++++----- >>> fs/f2fs/segment.c | 3 ++- >>> fs/f2fs/super.c | 3 ++- >>> include/trace/events/f2fs.h | 11 ++++++++--- >>> 6 files changed, 30 insertions(+), 14 deletions(-) >>> >>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>> index 9920b2d6af8f..492af5b96de1 100644 >>> --- a/fs/f2fs/f2fs.h >>> +++ b/fs/f2fs/f2fs.h >>> @@ -1271,6 +1271,7 @@ 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 d0547bef0851..216081ea8c81 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; >>> @@ -2350,7 +2351,8 @@ 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; >>> @@ -2391,7 +2393,8 @@ 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; >>> @@ -2837,7 +2840,8 @@ 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 e275b72bc65f..10b24b0f13a5 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 return value is not zero, no victim was selected */ >>> if (f2fs_gc(sbi, &gc_control)) >>> @@ -1761,6 +1762,7 @@ 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), >>> @@ -1823,12 +1825,13 @@ 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, >>> - (gc_type == FG_GC) ? sec_freed : 0, 0)) >>> + if (gc_control->init_gc_type == FG_GC || >>> + !has_not_enough_free_secs(sbi, >>> + (gc_type == FG_GC) ? sec_freed : 0, 0)) { >> >> In all gc_control->init_gc_type = BG_GC cases, gc_control->no_bg_gc is true, >> if gc_type = BG_GC, then it should break out due to below condition. >> >> /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */ >> if (gc_type == BG_GC && gc_control->no_bg_gc) { >> ret = -EINVAL; >> goto stop; >> } >> >> Otherwise gc_type should always be FG_GC in >> !has_not_enough_free_secs(sbi, (gc_type == FG_GC) ? sec_freed : 0, 0), right? > > We can have gc_type=BG_GC and gc_control->no_bg_gc=false, which is a normal > background GC path. Okay, actually if gc_type = BG_GC, sec_freed should be zero at the most time. Looks fine to me. Reviewed-by: Chao Yu Thanks, > >> >> Thanks, >> >>> + if (gc_mode == 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) { >>> @@ -1849,6 +1852,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) >>> if (ret) >>> goto stop; >>> } >>> +go_gc_more: >>> segno = NULL_SEGNO; >>> goto gc_more; >>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >>> index 8b4f2b1d2cca..0a4180f64291 100644 >>> --- a/fs/f2fs/segment.c >>> +++ b/fs/f2fs/segment.c >>> @@ -404,7 +404,8 @@ 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 }; >>> f2fs_down_write(&sbi->gc_lock); >>> f2fs_gc(sbi, &gc_control); >>> } >>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c >>> index a28c27eed6d0..63daae67a9d9 100644 >>> --- a/fs/f2fs/super.c >>> +++ b/fs/f2fs/super.c >>> @@ -2080,7 +2080,8 @@ 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 54ec9e543f09..16c67ede85b6 100644 >>> --- a/include/trace/events/f2fs.h >>> +++ b/include/trace/events/f2fs.h >>> @@ -645,18 +645,21 @@ 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) >>> @@ -670,6 +673,7 @@ 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; >>> @@ -679,12 +683,13 @@ 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->gc_type == BG_GC) ? __entry->no_bg_gc : -1, >>> + __entry->nr_free_secs, >>> __entry->dirty_nodes, >>> __entry->dirty_dents, >>> __entry->dirty_imeta,