On 2026/10/10 18:16, illofspeed wrote:
> dmz_reclaim_work() re-arms its DMZ_IDLE_PERIOD poll only when
> dmz_should_reclaim() returns false at the start of a pass. After a pass
> it calls dmz_schedule_reclaim(), which queues the work only if reclaim
> is needed right now. When a pass ends while the target is still busy and
> has enough free zones, nothing is queued at all. Once the target goes
> idle, nothing re-evaluates dmz_should_reclaim() until new I/O arrives or
> user space sends a "reclaim" message, so the random or cache zones that
> filled up under load stay full.
>
> Seen on md RAID5 members on 27 TB host-managed drives: after heavy
> writes the random zones stayed full for hours on idle targets; the
> workaround was a timer sending "dmsetup message <dev> 0 reclaim". With
> this patch the emptied and filled zones were reclaimed within minutes of
> the targets going idle, without the timer.
>
> After a pass, requeue the work immediately if reclaim is still needed,
> otherwise re-arm the idle poll.
>
> Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target")
> Assisted-by: LLM
> Signed-off-by: illofspeed <[email protected]>
Patch looks OK to me, but same comment as patch 1 about your SoB name. Please
confirm.
> ---
> drivers/md/dm-zoned-reclaim.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/dm-zoned-reclaim.c b/drivers/md/dm-zoned-reclaim.c
> index 2bcc163d209..7feb2628bd0 100644
> --- a/drivers/md/dm-zoned-reclaim.c
> +++ b/drivers/md/dm-zoned-reclaim.c
> @@ -557,7 +557,16 @@ static void dmz_reclaim_work(struct work_struct *work)
> }
> }
>
> - dmz_schedule_reclaim(zrc);
> + /*
> + * Keep the worker alive: when a pass ends while the target is busy
> + * with enough free zones, dmz_schedule_reclaim() queues nothing and
> + * the idle poll is never re-armed, so zones filled under load are not
> + * reclaimed once the target goes idle.
> + */
> + if (dmz_should_reclaim(zrc, dmz_reclaim_percentage(zrc)))
> + mod_delayed_work(zrc->wq, &zrc->work, 0);
> + else
> + mod_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);
> }
>
> /*
--
Damien Le Moal
Western Digital Research
