Messages in this thread | | | Date | Thu, 10 Apr 2008 14:39:27 +0530 | From | Balbir Singh <> | Subject | Re: [-mm] Add an owner to the mm_struct (v8) |
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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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