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Date:   Tue, 20 Oct 2020 11:27:07 -0700
From:   jaegeuk@kernel.org
To:     Can Guo <cang@codeaurora.org>
Cc:     linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com, Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>
Subject: Re: [PATCH 3/4] scsi: ufs: use WQ_HIGHPRI for gating work
Message-ID: <20201020182707.GA1087816@google.com>
References: <20201005223635.2922805-1-jaegeuk@kernel.org>
 <20201005223635.2922805-3-jaegeuk@kernel.org>
 <5c383fd90a0e97dbd1fffc35574133c9@codeaurora.org>
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On 10/20, Can Guo wrote:
> On 2020-10-06 06:36, Jaegeuk Kim wrote:
> > From: Jaegeuk Kim <jaegeuk@google.com>
> > 
> > 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@samsung.com>
> > Cc: Avri Altman <avri.altman@wdc.com>
> > Cc: Can Guo <cang@codeaurora.org>
> > Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
> > ---
> >  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;