On 02/19, Chao Yu wrote: > On 2020/2/19 7:27, Jaegeuk Kim wrote: > > On 02/17, Chao Yu wrote: > >> On 2020/2/15 2:58, Jaegeuk Kim wrote: > >>> FG_GC needs to move entire section more quickly. > >>> > >>> Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org> > >>> --- > >>> fs/f2fs/gc.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > >>> index bbf4db3f6bb4..1676eebc8c8b 100644 > >>> --- a/fs/f2fs/gc.c > >>> +++ b/fs/f2fs/gc.c > >>> @@ -1203,7 +1203,7 @@ static int do_garbage_collect(struct f2fs_sb_info > >>> *sbi, > >>> > >>> if (get_valid_blocks(sbi, segno, false) == 0) > >>> goto freed; > >>> - if (__is_large_section(sbi) && > >>> + if (gc_type == BG_GC && __is_large_section(sbi) && > >>> migrated >= sbi->migration_granularity) > >> > >> I knew migrating one large section is a more efficient way, but this can > >> increase long-tail latency of f2fs_balance_fs() occasionally, especially in > >> extreme fragmented space. > > > > FG_GC requires to wait for whole section migration which shows the entire > > latency. > > That will cause long-tail latency for single f2fs_balance_fs() procedure, > which it looks a very long hang when userspace call f2fs syscall, so why > not splitting total elapsed time into several f2fs_balance_fs() to avoid that.
Then, other ops can easily make more dirty segments. The intention of FG_GC is to block everything and make min. free segments as a best shot. > > Thanks, > > > > >> > >> Thanks, > >> > >>> goto skip; > >>> if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi))) > >>> > > . > > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
