LGTM-- in my staging branch. Reviewed-by: Michael Lyle <mlyle@xxxxxxxx> On 02/05/2018 08:20 PM, 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. > > Changelog: > v2: fix a rebase typo in v4, which is pointed out by Michael Lyle. > v1: initial version. > > Signed-off-by: Coly Li <colyli@xxxxxxx> > Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> > Cc: Michael Lyle <mlyle@xxxxxxxx> > --- > drivers/md/bcache/sysfs.c | 4 +++- > drivers/md/bcache/writeback.c | 2 +- > drivers/md/bcache/writeback.h | 3 +++ > 3 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c > index c524305cc9a7..4a6a697e1680 100644 > --- a/drivers/md/bcache/sysfs.c > +++ b/drivers/md/bcache/sysfs.c > @@ -218,7 +218,9 @@ STORE(__cached_dev) > sysfs_strtoul_clamp(writeback_rate, > dc->writeback_rate.rate, 1, INT_MAX); > > - d_strtoul_nonzero(writeback_rate_update_seconds); > + sysfs_strtoul_clamp(writeback_rate_update_seconds, > + dc->writeback_rate_update_seconds, > + 1, WRITEBACK_RATE_UPDATE_SECS_MAX); > 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 58218f7e77c3..f1d2fc15abcc 100644 > --- a/drivers/md/bcache/writeback.c > +++ b/drivers/md/bcache/writeback.c > @@ -655,7 +655,7 @@ 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
