Date: Sat, 27 Aug 2016 19:05:01 -0700 From: Adrian Chadd <adrian@freebsd.org> To: Slawa Olhovchenkov <slw@zxy.spb.ru> Cc: Bruce Simpson <bms@fastmail.net>, Ryan Stone <rysto32@gmail.com>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, Ryan Stone <rstone@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org> Subject: Re: svn commit: r304436 - in head: . sys/netinet Message-ID: <CAJ-VmokC-8hW6uJaORLFQmb_nHdevHbVbBGVS3xGghs3jOKofg@mail.gmail.com> In-Reply-To: <20160827004617.GJ88122@zxy.spb.ru> References: <8ac23bd1-dcb3-7c64-f195-5039f9af0eaf@fastmail.net> <20160821000400.GY8192@zxy.spb.ru> <20160826144926.GE88122@zxy.spb.ru> <3dba1b70-54cc-0bb1-5cc8-8c56cd750bec@fastmail.net> <20160826151324.GF88122@zxy.spb.ru> <CAJ-Vmomg6ejJdZessaUU3DF%2BV%2BsQd=hMZwo_pDYpa4XjoB_ZcA@mail.gmail.com> <20160826213613.GH88122@zxy.spb.ru> <CAJ-VmomRDdg5EUUiAHOyVBzitd8cZ8bPGCrU9btnveWeW-_85g@mail.gmail.com> <20160826220255.GI88122@zxy.spb.ru> <CAJ-VmomFuh07_vBi%2BzdNrPs3%2BDni1AtYh_VNKbnACydbCxr7gw@mail.gmail.com> <20160827004617.GJ88122@zxy.spb.ru>
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On 26 August 2016 at 17:46, Slawa Olhovchenkov <slw@zxy.spb.ru> wrote:
> On Fri, Aug 26, 2016 at 04:55:34PM -0700, Adrian Chadd wrote:
>
>> Hi,
>>
>> I use the kernel lock profiling debugging,
>
> I am already have 100% utilise all CPU cores, I think this is drop
> performance?
>
>> but you can use dtrace to
>> get an idea:
>>
>> dtrace -n 'lockstat:::adaptive-block { @[stack()] = sum(arg1); }'
>
> How to interpret results (how to distinct lock contention from lock
> cost/overhead (LOCK CMPXCGQ is very expensive))?
well, paste the results? :)
the lock is expensive because it's contended. :)
-a
>> (https://wiki.freebsd.org/DTrace/One-Liners)
>>
>>
>>
>> -adrian
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