Re: [LKP] [lkp] [locking/mutexes] cb4bbc457b: -40.0% unixbench.score

2016-01-24 Thread Paul E. McKenney
On Mon, Jan 25, 2016 at 09:23:59AM +0800, Huang, Ying wrote:
> Davidlohr Bueso  writes:
> 
> > On Fri, 22 Jan 2016, kernel test robot wrote:
> >
> >>FYI, we noticed the below changes on
> >>
> >>https://github.com/0day-ci/linux
> >> Ding-Tianhong/locking-mutexes-don-t-spin-on-owner-when-wait-list-is-not-NULL/20160121-173317
> >>commit cb4bbc457bfed6194ffab1b10c7be73b3f16ca2d ("locking/mutexes: don't 
> >>spin on owner when wait list is not NULL.")
> >
> > I'm not sure why this would even be reported, as this patch has not been 
> > accepted
> > or acked or nothin', by anyone.
> 
> Sorry for bothering.  The purpose is FYI as in the original report
> email.  We test patches posted to LKML, if we found some changes related
> to the patch, we will send out a report.  Hope the reviewer could
> take that as information for his/her review if the report isn't totally
> nonsense.

For me, the 0day reports on LKML postings have been quite helpful.  They
give the submitter immediate feedback on a number of issues, thus reducing
the number of rounds of review.

Thanx, Paul



Re: [LKP] [lkp] [locking/mutexes] cb4bbc457b: -40.0% unixbench.score

2016-01-24 Thread Huang, Ying
Davidlohr Bueso  writes:

> On Fri, 22 Jan 2016, kernel test robot wrote:
>
>>FYI, we noticed the below changes on
>>
>>https://github.com/0day-ci/linux
>> Ding-Tianhong/locking-mutexes-don-t-spin-on-owner-when-wait-list-is-not-NULL/20160121-173317
>>commit cb4bbc457bfed6194ffab1b10c7be73b3f16ca2d ("locking/mutexes: don't spin 
>>on owner when wait list is not NULL.")
>
> I'm not sure why this would even be reported, as this patch has not been 
> accepted
> or acked or nothin', by anyone.

Sorry for bothering.  The purpose is FYI as in the original report
email.  We test patches posted to LKML, if we found some changes related
to the patch, we will send out a report.  Hope the reviewer could
take that as information for his/her review if the report isn't totally
nonsense.

> In this particular case that raw performance drop
> is because spinning is pretty much disabled by Ding's change. Totally 
> expected for
> the kind of workload unixbench triggers.

The report is just raw performance data, it still need people to explain
it.  Thanks a lot for your explanation.

> All this does is hurt lkml-searchability.

Sorry, I don't understand this.  You could still search the original
patch.  Could you explain a little?

Best Regards,
Huang, Ying

> Thanks,
> Davidlohr
> ___
> LKP mailing list
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Re: [lkp] [locking/mutexes] cb4bbc457b: -40.0% unixbench.score

2016-01-21 Thread Davidlohr Bueso

On Fri, 22 Jan 2016, kernel test robot wrote:


FYI, we noticed the below changes on

https://github.com/0day-ci/linux 
Ding-Tianhong/locking-mutexes-don-t-spin-on-owner-when-wait-list-is-not-NULL/20160121-173317
commit cb4bbc457bfed6194ffab1b10c7be73b3f16ca2d ("locking/mutexes: don't spin on 
owner when wait list is not NULL.")


I'm not sure why this would even be reported, as this patch has not been 
accepted
or acked or nothin', by anyone. In this particular case that raw performance 
drop
is because spinning is pretty much disabled by Ding's change. Totally expected 
for
the kind of workload unixbench triggers.

All this does is hurt lkml-searchability.

Thanks,
Davidlohr