Re: [PATCH 3/4] scsi: ufs: use WQ_HIGHPRI for gating work

From: jaegeuk
Date: Tue Oct 20 2020 - 14:27:11 EST


On 10/20, Can Guo wrote:
> On 2020-10-06 06:36, Jaegeuk Kim wrote:
> > From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> >
> > Must have WQ_MEM_RECLAIM
> > ``WQ_MEM_RECLAIM``
> > All wq which might be used in the memory reclaim paths **MUST**
> > have this flag set. The wq is guaranteed to have at least one
> > execution context regardless of memory pressure.
> >
>
> The commit msg is not telling the same story as the change/title does.

This message explains why we need to keep WQ_MEM_RECLAIM when adding WQ_HIGHPRI.

Thanks,

>
> Regards,
>
> Can Guo.
>
> > Cc: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > Cc: Avri Altman <avri.altman@xxxxxxx>
> > Cc: Can Guo <cang@xxxxxxxxxxxxxx>
> > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> > ---
> > drivers/scsi/ufs/ufshcd.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 0bb07b50bd23e..76e95963887be 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -1849,7 +1849,7 @@ static void ufshcd_init_clk_gating(struct ufs_hba
> > *hba)
> > snprintf(wq_name, ARRAY_SIZE(wq_name), "ufs_clk_gating_%d",
> > hba->host->host_no);
> > hba->clk_gating.clk_gating_workq = alloc_ordered_workqueue(wq_name,
> > - WQ_MEM_RECLAIM);
> > + WQ_MEM_RECLAIM | WQ_HIGHPRI);
> >
> > hba->clk_gating.is_enabled = true;