On 2017/10/10 上午10:44, tang.junhui@xxxxxxxxxx wrote:
> From: Tang Junhui <tang.junhui@xxxxxxxxxx>
>
> I try to execute the following command to trigger gc thread:
> [root@localhost internal]# echo 1 > trigger_gc
> But it does not work, I debug the code in gc_should_run(), It works only
> if in invalidating or sectors_to_gc < 0. So set sectors_to_gc to -1 to
> meet the condition when we trigger gc by manual command.
>
> Signed-off-by: Tang Junhui <tang.junhui@xxxxxxxxxx>
Hi Junhui,
This patch is in mainline kernel v4.14 already, there is the upstream
patch head,
commit 0b43f49dc4d6d3789e936731dc16af94cb57d568
Author: Tang Junhui <tang.junhui@xxxxxxxxxx>
Date: Wed Sep 6 14:25:55 2017 +0800
bcache: gc does not work when triggering by manual command
I try to execute the following command to trigger gc thread:
[root@localhost internal]# echo 1 > trigger_gc
But it does not work, I debug the code in gc_should_run(), It works only
if in invalidating or sectors_to_gc < 0. So set sectors_to_gc to -1 to
meet the condition when we trigger gc by manual command.
(Code comments aded by Coly Li)
Signed-off-by: Tang Junhui <tang.junhui@xxxxxxxxxx>
Reviewed-by: Coly Li <colyli@xxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> ---
> drivers/md/bcache/sysfs.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
> index b3ff57d..bef776d 100644
> --- a/drivers/md/bcache/sysfs.c
> +++ b/drivers/md/bcache/sysfs.c
> @@ -614,8 +614,16 @@ STORE(__bch_cache_set)
> bch_cache_accounting_clear(&c->accounting);
> }
>
> - if (attr == &sysfs_trigger_gc)
> + if (attr == &sysfs_trigger_gc) {
> + /*
> + * Satisfy the gc condition by setting sectors_to_gc under 0,
> + * sectors_to_gc may also be decreased under 0 in
> + * bch_data_insert_start() and gc would be triggered again,
> + * but the race is rare, and harmless, so we can ignore it
> + */
> + atomic_set(&c->sectors_to_gc, -1);
> wake_up_gc(c);
> + }
>
> if (attr == &sysfs_prune_cache) {
> struct shrink_control sc;
>
--
Coly Li
