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Date: Wed, 19 Jan 2011 21:25:54 +0530
From: Ciju Rajan K <ciju@linux.vnet.ibm.com>
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To: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>,
        lkml <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
        Bharata B Rao <bharata@linux.vnet.ibm.com>,
        Srivatsa Vaddagiri <vatsa@in.ibm.com>,
        Ciju Rajan K <ciju@linux.vnet.ibm.com>
Subject: Re: [RFC][PATCH 0/2 v1.0]sched: updating /proc/schedstat
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>>
>> This patch set removes only those fields which are currently not in use.
>> If you observe the fields of /proc/schedstat the following fields are not
>> being updated.
> 
> Ah... I misunderstood the meaning of `unused' and complained based on too
> old kernel's source. Sorry.> 

> I confirmed that these fields are actually not treated by upstream kernel
> at all. So I think it's OK if any userland tools are updated synchronized
> with this change.

Thanks for verifying it.

 Does its benefit is more than its cost? In my
> understanding, its benefit is improving readability and reducing some memory
> footprint, and its cost is changing all userspace tools referring /proc/schedstat.

In my opinion we should go ahead with updating /proc/schedstat. 
As I mentioned earlier, we can have an updated script for 
http://eaglet.rain.com/rick/linux/schedstat/ 

> 
> # Unfortunately I don't know how much it costs.

The changes required in the userspace would be very small. 
Its just a matter of re-ordering the values. I also can't think
of much complicated scenario than this.

-Ciju
>