Re: [-mm] Add an owner to the mm_struct (v8)

[Balbir Singh <balbir@linux.vnet.ibm.com>]

Paul Menage wrote:
> On Tue, Apr 8, 2008 at 12:05 AM, Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
>> Paul Menage wrote:
>>  > On Mon, Apr 7, 2008 at 11:52 PM, Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
>>  >>  I agree, but like I said earlier, this was the easily available ready made
>>  >>  application I found. Do you know of any other highly threaded micro benchmark?
>>  >>
>>  >
>>  > How about a simple program that creates N threads that just sleep,
>>  > then has the main thread exit?
>>  >
>>
>>  That is not really representative of anything. I have that program handy. How do
>>  we measure the impact on throughput?
> 
> It's very representative of how much additional overhead in terms of
> mm->owner churn there is in a large multi-threaded application
> exiting, which is the thing that you're trying to optimize with the
> delayed thread group leader checks.
> 

I see almost no overhead after the notification change optimization (notify only
if owner belongs to a different cgroup).

My program creates n processes with k threads each and forces the thread group
leader to exit. For my experiment I created 10 processes with 800 threads each
(NOTE: you need to change ulimit -s for this to work).

I am going to remove the delay_group_leader() optimization and submit v9.

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

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