Messages in this thread | | | Date | Thu, 04 Dec 2014 18:14:08 +0200 | From | Tanya Brokhman <> | Subject | Re: [PATCH 2/6] UBI: Fastmap: Ensure that only one fastmap work is scheduled |
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On 11/24/2014 3:20 PM, Richard Weinberger wrote: > If the WL pool runs out of PEBs we schedule a fastmap write > to refill it as soon as possible. > Ensure that only one at a time is scheduled otherwise we might end in > a fastmap write storm because writing the fastmap can schedule another > write if bitflips are detected. >
Reviewed-by: Tanya Brokhman <tlinder@codeaurora.org>
> Signed-off-by: Richard Weinberger <richard@nod.at> > --- > drivers/mtd/ubi/ubi.h | 4 +++- > drivers/mtd/ubi/wl.c | 8 +++++++- > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h > index f80ffab..04c4c05 100644 > --- a/drivers/mtd/ubi/ubi.h > +++ b/drivers/mtd/ubi/ubi.h > @@ -427,6 +427,7 @@ struct ubi_debug_info { > * @fm_size: fastmap size in bytes > * @fm_sem: allows ubi_update_fastmap() to block EBA table changes > * @fm_work: fastmap work queue > + * @fm_work_scheduled: non-zero if fastmap work was scheduled > * > * @used: RB-tree of used physical eraseblocks > * @erroneous: RB-tree of erroneous used physical eraseblocks > @@ -438,7 +439,7 @@ struct ubi_debug_info { > * @pq_head: protection queue head > * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from, > * @move_to, @move_to_put @erase_pending, @wl_scheduled, @works, > - * @erroneous, and @erroneous_peb_count fields > + * @erroneous, @erroneous_peb_count, and @fm_work_scheduled fields > * @move_mutex: serializes eraseblock moves > * @work_sem: used to wait for all the scheduled works to finish and prevent > * new works from being submitted > @@ -533,6 +534,7 @@ struct ubi_device { > void *fm_buf; > size_t fm_size; > struct work_struct fm_work; > + int fm_work_scheduled; > > /* Wear-leveling sub-system's stuff */ > struct rb_root used; > diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c > index 834f6fe..7f135df 100644 > --- a/drivers/mtd/ubi/wl.c > +++ b/drivers/mtd/ubi/wl.c > @@ -149,6 +149,9 @@ static void update_fastmap_work_fn(struct work_struct *wrk) > { > struct ubi_device *ubi = container_of(wrk, struct ubi_device, fm_work); > ubi_update_fastmap(ubi); > + spin_lock(&ubi->wl_lock); > + ubi->fm_work_scheduled = 0; > + spin_unlock(&ubi->wl_lock); > } > > /** > @@ -660,7 +663,10 @@ static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi) > /* We cannot update the fastmap here because this > * function is called in atomic context. > * Let's fail here and refill/update it as soon as possible. */ > - schedule_work(&ubi->fm_work); > + if (!ubi->fm_work_scheduled) { > + ubi->fm_work_scheduled = 1; > + schedule_work(&ubi->fm_work); > + } > return NULL; > } else { > pnum = pool->pebs[pool->used++]; >
Thanks, Tanya Brokhman -- Qualcomm Israel, on behalf of Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
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