| Message ID | 20180127142406.89741-2-colyli@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/27/2018 06:23 AM, Coly Li wrote: > dc->writeback_rate_update_seconds can be set via sysfs and its value can > be set to [1, ULONG_MAX]. It does not make sense to set such a large > value, 60 seconds is long enough value considering the default 5 seconds > works well for long time. > > Because dc->writeback_rate_update is a special delayed work, it re-arms > itself inside the delayed work routine update_writeback_rate(). When > stopping it by cancel_delayed_work_sync(), there should be a timeout to > wait and make sure the re-armed delayed work is stopped too. A small max > value of dc->writeback_rate_update_seconds is also helpful to decide a > reasonable small timeout. > > This patch limits sysfs interface to set dc->writeback_rate_update_seconds > in range of [1, 60] seconds, and replaces the hand-coded number by macros. > > Signed-off-by: Coly Li <colyli@suse.de> > Reviewed-by: Hannes Reinecke <hare@suse.com> [snip] > --- > drivers/md/bcache/sysfs.c | 3 +++ > drivers/md/bcache/writeback.c | 2 +- > drivers/md/bcache/writeback.h | 3 +++ > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c > index b4184092c727..a74a752c9e0f 100644 > --- a/drivers/md/bcache/sysfs.c > +++ b/drivers/md/bcache/sysfs.c > @@ -215,6 +215,9 @@ STORE(__cached_dev) > sysfs_strtoul_clamp(writeback_rate, > dc->writeback_rate.rate, 1, INT_MAX); > > + sysfs_strtoul_clamp(writeback_rate_update_seconds, > + dc->writeback_rate_update_seconds, > + 1, WRITEBACK_RATE_UPDATE_SECS_MAX); > d_strtoul_nonzero(writeback_rate_update_seconds); Doesn't the above line need to be removed for this to work? Mike
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index b4184092c727..a74a752c9e0f 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -215,6 +215,9 @@ STORE(__cached_dev) sysfs_strtoul_clamp(writeback_rate, dc->writeback_rate.rate, 1, INT_MAX); + sysfs_strtoul_clamp(writeback_rate_update_seconds, + dc->writeback_rate_update_seconds, + 1, WRITEBACK_RATE_UPDATE_SECS_MAX); d_strtoul_nonzero(writeback_rate_update_seconds); d_strtoul(writeback_rate_i_term_inverse); d_strtoul_nonzero(writeback_rate_p_term_inverse); diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index 51306a19ab03..0ade883b6316 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -652,7 +652,7 @@ void bch_cached_dev_writeback_init(struct cached_dev *dc) dc->writeback_rate.rate = 1024; dc->writeback_rate_minimum = 8; - dc->writeback_rate_update_seconds = 5; + dc->writeback_rate_update_seconds = WRITEBACK_RATE_UPDATE_SECS_DEFAULT; dc->writeback_rate_p_term_inverse = 40; dc->writeback_rate_i_term_inverse = 10000; diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h index 66f1c527fa24..587b25599856 100644 --- a/drivers/md/bcache/writeback.h +++ b/drivers/md/bcache/writeback.h @@ -8,6 +8,9 @@ #define MAX_WRITEBACKS_IN_PASS 5 #define MAX_WRITESIZE_IN_PASS 5000 /* *512b */ +#define WRITEBACK_RATE_UPDATE_SECS_MAX 60 +#define WRITEBACK_RATE_UPDATE_SECS_DEFAULT 5 + /* * 14 (16384ths) is chosen here as something that each backing device * should be a reasonable fraction of the share, and not to blow up