Re: [f2fs-dev] [PATCH 2/3] f2fs: run GCs synchronously given user requests

[Chao Yu]

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?

Thanks,

> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
>   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)