Re: [PATCH] bcache: remove unnecessary code in gc

Re: [PATCH] bcache: remove unnecessary code in gc

[Coly Li]

On 10/6/21 4:04 PM, Li Lei wrote:
> Originally, btree_gc_start() ran in workqueue, it would be called
> simutaneously in different threads, c->gc_mark_valid was used to make
> sure there was only one thread to do GC.
>
> Since gc has been converted to a kthread, there is no need to the check.
>
> Signed-off-by: Li Lei <lilei@szsandstone.com>
> ---
>   drivers/md/bcache/btree.c | 3 ---
>   1 file changed, 3 deletions(-)
>
> diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
> index fe6dce125aba..b18e1fd2c209 100644
> --- a/drivers/md/bcache/btree.c
> +++ b/drivers/md/bcache/btree.c
> @@ -1698,9 +1698,6 @@ static void btree_gc_start(struct cache_set *c)
>   	struct cache *ca;
>   	struct bucket *b;
>
> -	if (!c->gc_mark_valid)
> -		return;
> -

Do you have any performance number for the above change ? I am not sure 
whether the change may offer benefit for bcache gc, correct me if I am 
wrong.

Coly Li

>   	mutex_lock(&c->bucket_lock);
>
>   	c->gc_mark_valid = 0;
> --
> 2.25.1
>
>
>
>