On 2020/11/5 22:19, Dongdong Tao wrote: > From: dongdong tao <dongdong.tao@xxxxxxxxxxxxx> > > commit 9aaf51654672 ("bcache: make cutoff_writeback and > cutoff_writeback_sync tunable") intend to make these two option > configurable by user, but these two are still read-only. > > Signed-off-by: dongdong tao <dongdong.tao@xxxxxxxxxxxxx> > --- > drivers/md/bcache/sysfs.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c > index 554e3afc9b68..81f4a681705c 100644 > --- a/drivers/md/bcache/sysfs.c > +++ b/drivers/md/bcache/sysfs.c > @@ -102,8 +102,8 @@ read_attribute(writeback_keys_done); > read_attribute(writeback_keys_failed); > read_attribute(io_errors); > read_attribute(congested); > -read_attribute(cutoff_writeback); > -read_attribute(cutoff_writeback_sync); > +rw_attribute(cutoff_writeback); > +rw_attribute(cutoff_writeback_sync); > rw_attribute(congested_read_threshold_us); > rw_attribute(congested_write_threshold_us); > > @@ -902,6 +902,8 @@ STORE(__bch_cache_set) > sysfs_strtoul_bool(copy_gc_enabled, c->copy_gc_enabled); > sysfs_strtoul_bool(idle_max_writeback_rate, > c->idle_max_writeback_rate_enabled); > + sysfs_strtoul_clamp(cutoff_writeback, bch_cutoff_writeback, 1, 100); > + sysfs_strtoul_clamp(cutoff_writeback_sync, bch_cutoff_writeback_sync, 1, 100); > NACK, we only support the default value. Commit 9aaf51654672 ("bcache: make cutoff_writeback and cutoff_writeback_sync tunable") clearly announced the purpose was for research and experiment. Coly Li