On Thu, 6 Feb 2014 15:17:26 +0100, Andreas Rohner wrote:
> This patch adds a flag, that enables the GC to skip the timeout in
> certain situations. For example if the cleaning of some segments
> was deferred to a later time, then no real progress has been
> made. Apart from reading a few summary blocks, no data was read or
> written to disk. In this situation it makes sense to skip the
> normal timeout once and immediately try to clean the next set of
> segments.
>
> Unfortunately it is not possible, to directly continue the cleaning
> loop, because this would lead to an unresponsive GC process.
> Therefore the timeout is simply set to 0 seconds.
>
> Signed-off-by: Andreas Rohner <andreas.rohner@xxxxxxx>
> ---
> sbin/cleanerd/cleanerd.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/sbin/cleanerd/cleanerd.c b/sbin/cleanerd/cleanerd.c
> index 4c9f69b..3506c20 100644
> --- a/sbin/cleanerd/cleanerd.c
> +++ b/sbin/cleanerd/cleanerd.c
> @@ -141,6 +141,7 @@ const static struct option long_option[] = {
> * @running: running state
> * @fallback: fallback state
> * @retry_cleaning: retrying reclamation for protected segments
> + * @no_timeout: the next timeout will be 0 seconds
> * @ncleansegs: number of semgents cleaned per cycle
> * @cleaning_interval: cleaning interval
> * @target: target time for sleeping
> @@ -169,6 +170,7 @@ struct nilfs_cleanerd {
> int running;
> int fallback;
> int retry_cleaning;
> + int no_timeout;
> int shutdown;
> long ncleansegs;
> struct timeval cleaning_interval;
> @@ -896,7 +898,7 @@ static int nilfs_cleanerd_recalc_interval(struct nilfs_cleanerd *cleanerd,
> interval = nilfs_cleanerd_cleaning_interval(cleanerd);
> /* timercmp() does not work for '>=' or '<='. */
> /* curr >= target */
> - if (!timercmp(&curr, &cleanerd->target, <)) {
> + if (!timercmp(&curr, &cleanerd->target, <) || cleanerd->no_timeout) {
> cleanerd->timeout.tv_sec = 0;
> cleanerd->timeout.tv_usec = 0;
> timeradd(&curr, interval, &cleanerd->target);
> @@ -1428,6 +1430,7 @@ static int nilfs_cleanerd_clean_segments(struct nilfs_cleanerd *cleanerd,
> nilfs_cleanerd_progress(cleanerd, stat.deferred_segs);
> cleanerd->fallback = 0;
> cleanerd->retry_cleaning = 0;
> + cleanerd->no_timeout = 1;
>
> *ndone = stat.deferred_segs;
> } else {
> @@ -1501,6 +1504,8 @@ static int nilfs_cleanerd_clean_loop(struct nilfs_cleanerd *cleanerd)
> nilfs_cleanerd_clean_check_pause(cleanerd);
>
> while (!cleanerd->shutdown) {
> + cleanerd->no_timeout = 0;
> +
> if (sigprocmask(SIG_BLOCK, &sigset, NULL) < 0) {
> syslog(LOG_ERR, "cannot set signal mask: %m");
> return -1;
> --
> 1.8.5.3
This one looks good to me.
Regards,
Ryusuke Konishi
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