Messages in this thread Patch in this message | | | Date | Tue, 28 Jun 2022 15:59:01 +0800 | Subject | Re: [f2fs-dev] [PATCH 2/3] f2fs: run GCs synchronously given user requests | From | Chao Yu <> |
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On 2022/6/23 0:58, Jaegeuk Kim wrote: > On 06/22, Chao Yu wrote: >> On 2022/6/20 6:34, Jaegeuk Kim wrote: >>> On 06/19, Chao Yu wrote: >>>> On 2022/6/18 6:31, Jaegeuk Kim wrote: >>>>> When users set GC_URGENT or GC_MID, they expected to do GCs right away. >>>>> But, there's a condition to bypass it. Let's indicate we need to do now >>>>> in the thread. >>>> >>>> .should_migrate_blocks is used to force migrating blocks in full >>>> section, so what is the condition here? GC should not never select >>>> a full section, right? >>> >>> I think it'll move a full section given .victim_segno is not NULL_SEGNO, >>> as __get_victim will give a dirty segment all the time. wdyt? >> >> However, in gc_thread_fun() victim_segno is NULL_SEGNO all the time. > > What do you mean? The gc_thread thread sets NULL_SEGNO, which prevents > from selecting the full section. But, f2fs_ioc_flush_device will set the > segno to move, and f2fs_resize_fs calls do_garbage_collect directly.
Yes, but I didn't get why this patch updates .should_migrate_blocks for gc_thread_func() case? If this is added to avoid breaking from below condition, I guess it's not necessary, since victim selected from gc_thread_func() will always be dirty, so get_valid_blocks(sbi, segno, true) == BLKS_PER_SEC(sbi) will be false anyway? or am I missing something?
/* * stop BG_GC if there is not enough free sections. * Or, stop GC if the segment becomes fully valid caused by * race condition along with SSR block allocation. */ if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) || (!force_migrate && get_valid_blocks(sbi, segno, true) == BLKS_PER_SEC(sbi))) return submitted;
Thanks,
> >> >> I guess .should_migrate_blocks should only be set to true for >> F2FS_IOC_FLUSH_DEVICE/F2FS_IOC_RESIZE_FS case? rather than GC_URGENT or GC_MID >> case? See commit 7dede88659df ("f2fs: fix to allow migrating fully valid segment"). >> >> Thanks, >> >>> >>>> >>>> Thanks, >>>> >>>>> >>>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> >>>>> --- >>>>> fs/f2fs/gc.c | 8 ++++++-- >>>>> 1 file changed, 6 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >>>>> index d5fb426e0747..f4aa3c88118b 100644 >>>>> --- a/fs/f2fs/gc.c >>>>> +++ b/fs/f2fs/gc.c >>>>> @@ -37,7 +37,6 @@ static int gc_thread_func(void *data) >>>>> unsigned int wait_ms; >>>>> struct f2fs_gc_control gc_control = { >>>>> .victim_segno = NULL_SEGNO, >>>>> - .should_migrate_blocks = false, >>>>> .err_gc_skipped = false }; >>>>> wait_ms = gc_th->min_sleep_time; >>>>> @@ -113,7 +112,10 @@ static int gc_thread_func(void *data) >>>>> sbi->gc_mode == GC_URGENT_MID) { >>>>> wait_ms = gc_th->urgent_sleep_time; >>>>> f2fs_down_write(&sbi->gc_lock); >>>>> + gc_control.should_migrate_blocks = true; >>>>> goto do_gc; >>>>> + } else { >>>>> + gc_control.should_migrate_blocks = false; >>>>> } >>>>> if (foreground) { >>>>> @@ -139,7 +141,9 @@ static int gc_thread_func(void *data) >>>>> if (!foreground) >>>>> stat_inc_bggc_count(sbi->stat_info); >>>>> - sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC; >>>>> + sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC || >>>>> + sbi->gc_mode == GC_URGENT_HIGH || >>>>> + sbi->gc_mode == GC_URGENT_MID; >>>>> /* foreground GC was been triggered via f2fs_balance_fs() */ >>>>> if (foreground)
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