Re: [PATCH 1/2] memory: samsung: exynos5422-dmc: Adjust polling interval and uptreshold

[Lukasz Luba]

On 7/10/20 1:45 PM, Krzysztof Kozlowski wrote:
> On Fri, Jul 10, 2020 at 09:34:45AM +0100, Lukasz Luba wrote:
> > Hi Chanwoo,
> >
> > On 7/9/20 5:08 AM, Chanwoo Choi wrote:
> > > Hi Lukasz,
> > >
> > > On 7/9/20 12:34 AM, Lukasz Luba wrote:
> > > > In order to react faster and make better decisions under some workloads,
> > > > benchmarking the memory subsystem behavior, adjust the polling interval
> > > > and upthreshold value used by the simple_ondemand governor.
> > > >
> > > > Reported-by: Willy Wolff <willy.mh.wolff.ml@xxxxxxxxx>
> > > > Signed-off-by: Lukasz Luba <lukasz.luba@xxxxxxx>
> > > > ---
> > > >    drivers/memory/samsung/exynos5422-dmc.c | 4 ++--
> > > >    1 file changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
> > > > index 93e9c2429c0d..e03ee35f0ab5 100644
> > > > --- a/drivers/memory/samsung/exynos5422-dmc.c
> > > > +++ b/drivers/memory/samsung/exynos5422-dmc.c
> > > > @@ -1466,10 +1466,10 @@ static int exynos5_dmc_probe(struct platform_device *pdev)
> > > >    		 * Setup default thresholds for the devfreq governor.
> > > >    		 * The values are chosen based on experiments.
> > > >    		 */
> > > > -		dmc->gov_data.upthreshold = 30;
> > > > +		dmc->gov_data.upthreshold = 10;
> > > >    		dmc->gov_data.downdifferential = 5;
> > > > -		exynos5_dmc_df_profile.polling_ms = 500;
> > > > +		exynos5_dmc_df_profile.polling_ms = 100;
> > > >    	}
> > >
> > > Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> >
> > Thank you for the review. Do you think this patch could go through
> > your tree together with your patches?
> >
> > I don't know Krzysztof's opinion about the patch 2/2, but
> > I would expect, assuming the patch itself is correct, he would
> > like to take it into his next/dt branch.
>
> In the cover letter you mentioned that this is a follow up for the
> Chanwoo's patchset. But are these patches really depending on it? Can
> they be picked up independently?


They are not heavily dependent on Chanwoo's patches.
Yes, they can be picked up independently.
I just wanted to mention that the patch 1/2 was produced on the
code base which had already applied Chanwoo's patch for DMC.
If you like to take both 1/2 and 2/2 into your tree, it's good.

Thank you for having a look on this.

Regards,
Lukasz


> The DTS patch must go through arm soc, so I will take it. If it really
> depends on driver changes, then it has to wait for next release.
>
> Best regards,
> Krzysztof