On 2020/11/5 22:19, Dongdong Tao wrote:
> From: dongdong tao <dongdong....@canonical.com>
>
> 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....@canonical.com>
> ---
> 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
