From: Shailabh Nagar <nagar@watson.ibm.com>
To: Jes Sorensen <jes@trained-monkey.org>
Cc: Matt Helsley <matthltc@us.ibm.com>, Andrew Morton <akpm@osdl.org>,
Jay Lan <jlan@engr.sgi.com>, LKML <linux-kernel@vger.kernel.org>,
elsa-devel@lists.sourceforge.net, lse-tech@lists.sourceforge.net,
CKRM-Tech <ckrm-tech@lists.sourceforge.net>,
Paul Jackson <pj@sgi.com>, Erik Jacobson <erikj@sgi.com>,
Jack Steiner <steiner@sgi.com>, John Hesterberg <jh@sgi.com>
Subject: Re: [Lse-tech] Re: [ckrm-tech] Re: [PATCH 00/01] Move Exit Connectors
Date: Fri, 06 Jan 2006 16:45:05 +0000 [thread overview]
Message-ID: <43BE9E91.9060302@watson.ibm.com> (raw)
In-Reply-To: <yq08xttybrx.fsf@jaguar.mkp.net>
Jes Sorensen wrote:
>>>>>>"Matt" == Matt Helsley <matthltc@us.ibm.com> writes:
>
>
> Matt> Right. I forgot to repeat what I mentioned in the parent email
> Matt> -- that this patch is intended to be applied on top of
> Matt> Shailabh's patches.
>
> Matt> The first patch I posted (01/01) is intended for plain
> Matt> 2.6.15. Before proposing 01/01 for -mm I've been trying to see
> Matt> if there are any problems with the value of tsk->exit_signal
> Matt> before exit_mm() -- hence the "[RFC]" in the subject line of
> Matt> that one.
>
> Matt,
>
> Any chance one of you could put up a set of current patches somewhere?
I'll upload the delay accounting patches to a newly created lse-tech package.
> I am trying to make heads and tails of them and it's pretty hard as I
> haven't been on lse-tech for long and the lse-tech mailing list
> archives are useless due to the 99 to 1 SPAM ratio ;-(
>
> I am quite concerned about that lock your patches put into struct
> task_struct through struct task_delay_info. Have you done any
> measurements on how this impacts performance on highly threaded apps
> on larger system?
I don't expect the lock contention to be high. The lock is held for a
very short time (across two additions/increments). Moreover, it gets
contended only when the stats are being read (either through /proc or connectors).
Since the reading of stats won't be that frequent (the utility of these
numbers is to influence the I/O priority/rss limit etc. which won't be done
at a very small granularity anyway), I wouldn't expect a problem.
But its better to take some measurements anyway. Any suggestions on a
benchmark ?
> IMHO it seems to make more sense to use something like Jack's proposed
> task_notifier code to lock-less collect the data into task local data
> structures and then take the data from there and ship off to userland
> through netlink or similar like you are doing?
>
> I am working on modifying Jack's patch to carry task local data and
> use it for not just accounting but other areas that need optional
> callbacks (optional in the sense that it's a feature that can be
> enabled or disabled). Looking at Shailabh's delayacct_blkio() changes
> it seems that it would be really easy to fit those into that
> framework.
>
> Guess I should post some of this code .....
Please do. If this accounting can fit into some other framework, thats fine too.
-- Shailabh
> Cheers,
> Jes
>
next prev parent reply other threads:[~2006-01-06 16:44 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-03 23:16 [Patch 0/6] Per-task delay accounting Shailabh Nagar
2006-01-03 23:23 ` [Patch 1/6] Delay accounting: timespec diff Shailabh Nagar
2006-01-03 23:26 ` [Patch 2/6] Delay accounting: Initialization, kernel boot option Shailabh Nagar
2006-01-03 23:28 ` [Patch 3/6] Delay accounting: Sync block I/O delays Shailabh Nagar
2006-01-03 23:30 ` [Patch 4/6] Delay accounting: Swap in delays Shailabh Nagar
2006-01-03 23:31 ` [Patch 5/6] Delay accounting: /proc interface Shailabh Nagar
2006-01-03 23:33 ` [Patch 6/6] Delay accounting: Connector interface Shailabh Nagar
2006-01-04 0:21 ` Greg KH
2006-01-04 0:42 ` Shailabh Nagar
2006-01-04 0:51 ` Greg KH
2006-01-04 7:49 ` [Lse-tech] " Shailabh Nagar
2006-01-04 19:04 ` Jay Lan
2006-01-04 21:31 ` Shailabh Nagar
2006-01-04 22:40 ` [ckrm-tech] " Matt Helsley
2006-01-04 23:17 ` Andrew Morton
2006-01-05 18:42 ` [PATCH 00/01] Move Exit Connectors Matt Helsley
2006-01-05 19:17 ` [PATCH 01/01][RFC] " Matt Helsley
2006-01-05 19:20 ` [PATCH 00/01] " Matt Helsley
2006-01-05 23:10 ` Andrew Morton
2006-01-06 0:06 ` [ckrm-tech] " Matt Helsley
2006-01-06 8:57 ` [Lse-tech] " Jes Sorensen
2006-01-06 16:45 ` Shailabh Nagar [this message]
2006-01-11 10:36 ` Jes Sorensen
2006-01-11 12:56 ` John Hesterberg
2006-01-11 13:50 ` Jes Sorensen
2006-01-11 21:02 ` Matt Helsley
2006-01-11 21:39 ` John Hesterberg
2006-01-11 22:42 ` Matt Helsley
2006-01-12 10:01 ` Jes Sorensen
2006-01-12 23:20 ` Matt Helsley
2006-01-13 9:35 ` Jes Sorensen
2006-01-14 7:23 ` Matt Helsley
2006-01-12 3:29 ` Keith Owens
2006-01-12 5:04 ` Paul E. McKenney
2006-01-12 5:38 ` Keith Owens
2006-01-12 6:19 ` Keith Owens
2006-01-12 6:51 ` Paul E. McKenney
2006-01-12 7:50 ` Keith Owens
2006-01-12 15:17 ` Paul E. McKenney
2006-01-17 17:26 ` Paul E. McKenney
2006-01-17 23:57 ` Keith Owens
2006-01-18 2:49 ` Paul E. McKenney
2006-01-18 2:55 ` Lee Revell
2006-01-18 6:29 ` Paul E. McKenney
2006-01-12 5:26 ` Matt Helsley
2006-01-12 5:45 ` Keith Owens
2006-01-12 9:51 ` Jes Sorensen
2006-01-12 23:01 ` Matt Helsley
2006-01-13 9:59 ` Jes Sorensen
2006-01-13 10:38 ` Jes Sorensen
2006-01-13 23:22 ` Matt Helsley
2006-01-12 23:49 ` Matt Helsley
2006-01-05 0:01 ` [ckrm-tech] Re: [Patch 6/6] Delay accounting: Connector interface Shailabh Nagar
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