Messages in this thread | | | Date | Mon, 20 Jun 2022 08:00:38 +0200 | Subject | Re: [PATCH 3/4] scsi: pm8001: Use non-atomic bitmap ops for tag alloc + free | From | Hannes Reinecke <> |
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On 6/10/22 18:46, John Garry wrote: > In pm8001_tag_alloc() we don't require atomic set_bit() as we are already > in atomic context. In pm8001_tag_free() we should use the same host > spinlock to protect clearing the tag (and then don't require the atomic > clear_bit()). > > Signed-off-by: John Garry <john.garry@huawei.com> > --- > drivers/scsi/pm8001/pm8001_sas.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c > index 3a863d776724..8e3f2f9ddaac 100644 > --- a/drivers/scsi/pm8001/pm8001_sas.c > +++ b/drivers/scsi/pm8001/pm8001_sas.c > @@ -66,7 +66,11 @@ static int pm8001_find_tag(struct sas_task *task, u32 *tag) > void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag) > { > void *bitmap = pm8001_ha->tags; > - clear_bit(tag, bitmap); > + unsigned long flags; > + > + spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags); > + __clear_bit(tag, bitmap); > + spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags); > } > This spin lock is pretty much pointless; clear_bit() is always atomic.
Cheers,
Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
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