Re: [PATCH 1/2] cgroup: Set CGRP_RELEASABLE when adding to a cgroup

[Michael Bohan <mbohan@codeaurora.org>]

On 1/27/2011 5:30 PM, Paul Menage wrote:
> On Thu, Jan 27, 2011 at 5:17 PM, Bryan Huntsman<bryanh@codeaurora.org>  wrote:
>>
>> Tested-by: Mike Bohan<mbohan@codeaurora.org>
>>
>> I'm responding on Mike's behalf and adding him to this thread.  This
>> patch improves launch time of a test app from ~700ms to ~250ms on MSM,
>> with much lower variance across tests.  We also see UI latency
>> improvements, but have not quantified the gains.
>>
>
> Is this attached to the wrong patch? I'd thought that it was the other
> patch (removing the rcu_synchronize()) that's the performance booster.
> This one is more about preserving the semantics of the notification
> API.

You are correct. "[PATCH 2/2] cgroup: Remove call to synchronize_rcu in 
cgroup_attach_task" improved the performance.

To be more correct, I tested this patch (eg. "cgroup: Set 
CGRP_RELEASABLE when adding to a cgroup") to the degree that it didn't 
appear to cause any stability or functional regressions when performing 
the simple benchmark procedure described above. I did also test "[PATCH 
2/2] cgroup: Remove call to synchronize_rcu in cgroup_attach_task" 
independently of this patch to verify that it alone improved the 
performance.

Thanks,
Mike

-- 
Employee of Qualcomm Innovation Center, Inc.
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