Messages in this thread Patch in this message | | | Date | Sun, 8 May 2022 23:25:11 +0800 | Subject | Re: [f2fs-dev] [PATCH 4/5] f2fs: do not stop GC when requiring a free section | From | Chao Yu <> |
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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 <jaegeuk@kernel.org> > --- > 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?
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,
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