From: Andrea Arcangeli <aarcange@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
Paul Turner <pjt@google.com>,
Suresh Siddha <suresh.b.siddha@intel.com>,
Mike Galbraith <efault@gmx.de>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Lai Jiangshan <laijs@cn.fujitsu.com>,
Dan Smith <danms@us.ibm.com>,
Bharata B Rao <bharata.rao@gmail.com>,
Lee Schermerhorn <Lee.Schermerhorn@hp.com>,
Rik van Riel <riel@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC][PATCH 00/26] sched/numa
Date: Mon, 19 Mar 2012 15:30:02 +0100 [thread overview]
Message-ID: <20120319143002.GQ24602@redhat.com> (raw)
In-Reply-To: <4F673D73.90106@redhat.com>
On Mon, Mar 19, 2012 at 04:06:43PM +0200, Avi Kivity wrote:
> I agree with Peter on this, but perhaps it's because my app will take
> all of 15 minutes to patch. Up front knowledge is better than the
> kernel discovering it on its own.
I agree for qemu those soft bindings are fine.
But how you compute the statistical data is most difficult part, how
you collect them not so important after all.
The scheduler code Peter said is "that's not going to ever happen"
took several weeks of benchmarking and several rewrites to actual
materialize and be super happy about the core algorithm. If it's
simplified and just loops over the CPUs is because when you do
research and invent you can't waste time on actual implementation
details that just slow you down on the next rewrite of the algorithm
as you have to try again. So if my algorithms (abeit in a simplified
form compared to a real full implementation) works better, not having
the background scanning won't help Peter at all and you'll still be
better off with AutoNUMA.
When you focus only on the cost of collecting the information and no
actual discussion was spent yet on how to compute or react to it,
something's wrong... as that's the really interesting part of the code.
The fact the autonuma_balance() is simplified implementation is still
perfectly ok right now, as that's totally hidden kernel internal
thing, not even affecting kABI. Can be improved any time. Plus it's
not like it will backfire, it just won't be running as good as a full
more complex implementation that takes into account all the
runqueues. And implementating that won't be easy at all, there are
simpler things that are more urgent at this point.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2012-03-19 14:30 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-16 14:40 [RFC][PATCH 00/26] sched/numa Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 01/26] mm, mpol: Re-implement check_*_range() using walk_page_range() Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 02/26] mm, mpol: Remove NUMA_INTERLEAVE_HIT Peter Zijlstra
2012-07-06 10:32 ` Johannes Weiner
2012-07-06 14:48 ` Minchan Kim
2012-07-06 15:02 ` Peter Zijlstra
2012-07-06 14:54 ` Kyungmin Park
2012-07-06 15:00 ` Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 03/26] mm, mpol: add MPOL_MF_LAZY Peter Zijlstra
2012-03-23 11:50 ` Mel Gorman
2012-07-06 16:38 ` Rik van Riel
2012-07-06 20:04 ` Lee Schermerhorn
2012-07-06 20:27 ` Rik van Riel
2012-07-09 11:48 ` Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 04/26] mm, mpol: add MPOL_MF_NOOP Peter Zijlstra
2012-07-06 18:40 ` Rik van Riel
2012-03-16 14:40 ` [RFC][PATCH 05/26] mm, mpol: Check for misplaced page Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 06/26] mm: Migrate " Peter Zijlstra
2012-04-03 17:32 ` Dan Smith
2012-03-16 14:40 ` [RFC][PATCH 07/26] mm: Handle misplaced anon pages Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 08/26] mm, mpol: Simplify do_mbind() Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 09/26] sched, mm: Introduce tsk_home_node() Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 10/26] mm, mpol: Make mempolicy home-node aware Peter Zijlstra
2012-03-16 18:34 ` Christoph Lameter
2012-03-16 21:12 ` Peter Zijlstra
2012-03-19 13:53 ` Christoph Lameter
2012-03-19 14:05 ` Peter Zijlstra
2012-03-19 15:16 ` Christoph Lameter
2012-03-19 15:23 ` Peter Zijlstra
2012-03-19 15:31 ` Christoph Lameter
2012-03-19 17:09 ` Peter Zijlstra
2012-03-19 17:28 ` Peter Zijlstra
2012-03-19 19:06 ` Christoph Lameter
2012-03-19 20:28 ` Lee Schermerhorn
2012-03-19 21:21 ` Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 11/26] mm, mpol: Lazy migrate a process/vma Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 12/26] sched, mm: sched_{fork,exec} node assignment Peter Zijlstra
2012-06-15 18:16 ` Tony Luck
2012-06-20 19:12 ` [PATCH] sched: Fix build problems when CONFIG_NUMA=y and CONFIG_SMP=n Luck, Tony
2012-03-16 14:40 ` [RFC][PATCH 13/26] sched: Implement home-node awareness Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 14/26] sched, numa: Numa balancer Peter Zijlstra
2012-07-07 18:26 ` Rik van Riel
2012-07-09 12:05 ` Peter Zijlstra
2012-07-09 12:23 ` Peter Zijlstra
2012-07-09 12:40 ` Peter Zijlstra
2012-07-09 14:50 ` Rik van Riel
2012-07-08 18:35 ` Rik van Riel
2012-07-09 12:25 ` Peter Zijlstra
2012-07-09 14:54 ` Rik van Riel
2012-07-12 22:02 ` Rik van Riel
2012-07-13 14:45 ` Don Morris
2012-07-14 16:20 ` Rik van Riel
2012-03-16 14:40 ` [RFC][PATCH 15/26] sched, numa: Implement hotplug hooks Peter Zijlstra
2012-03-19 12:16 ` Srivatsa S. Bhat
2012-03-19 12:19 ` Peter Zijlstra
2012-03-19 12:27 ` Srivatsa S. Bhat
2012-03-16 14:40 ` [RFC][PATCH 16/26] sched, numa: Abstract the numa_entity Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 17/26] srcu: revert1 Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 18/26] srcu: revert2 Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 19/26] srcu: Implement call_srcu() Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 20/26] mm, mpol: Introduce vma_dup_policy() Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 21/26] mm, mpol: Introduce vma_put_policy() Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 22/26] mm, mpol: Split and explose some mempolicy functions Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 23/26] sched, numa: Introduce sys_numa_{t,m}bind() Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 24/26] mm, mpol: Implement numa_group RSS accounting Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 25/26] sched, numa: Only migrate long-running entities Peter Zijlstra
2012-07-08 18:34 ` Rik van Riel
2012-07-09 12:26 ` Peter Zijlstra
2012-07-09 14:53 ` Rik van Riel
2012-07-09 14:55 ` Peter Zijlstra
2012-03-16 14:40 ` [RFC][PATCH 26/26] sched, numa: A few debug bits Peter Zijlstra
2012-03-16 18:25 ` [RFC] AutoNUMA alpha6 Andrea Arcangeli
2012-03-19 18:47 ` Peter Zijlstra
2012-03-19 19:02 ` Andrea Arcangeli
2012-03-20 23:41 ` Dan Smith
2012-03-21 1:00 ` Andrea Arcangeli
2012-03-21 2:12 ` Andrea Arcangeli
2012-03-21 4:01 ` Dan Smith
2012-03-21 12:49 ` Andrea Arcangeli
2012-03-21 22:05 ` Dan Smith
2012-03-21 22:52 ` Andrea Arcangeli
2012-03-21 23:13 ` Dan Smith
2012-03-21 23:41 ` Andrea Arcangeli
2012-03-22 0:17 ` Andrea Arcangeli
2012-03-22 13:58 ` Dan Smith
2012-03-22 14:27 ` Andrea Arcangeli
2012-03-22 18:49 ` Andrea Arcangeli
2012-03-22 18:56 ` Dan Smith
2012-03-22 19:11 ` Andrea Arcangeli
2012-03-23 14:15 ` Andrew Theurer
2012-03-23 16:01 ` Andrea Arcangeli
2012-03-25 13:30 ` Andrea Arcangeli
2012-03-21 7:12 ` Ingo Molnar
2012-03-21 12:08 ` Andrea Arcangeli
2012-03-21 7:53 ` Ingo Molnar
2012-03-21 12:17 ` Andrea Arcangeli
2012-03-19 9:57 ` [RFC][PATCH 00/26] sched/numa Avi Kivity
2012-03-19 11:12 ` Peter Zijlstra
2012-03-19 11:30 ` Peter Zijlstra
2012-03-19 11:39 ` Peter Zijlstra
2012-03-19 11:42 ` Avi Kivity
2012-03-19 11:59 ` Peter Zijlstra
2012-03-19 12:07 ` Avi Kivity
2012-03-19 12:09 ` Peter Zijlstra
2012-03-19 12:16 ` Avi Kivity
2012-03-19 20:03 ` Peter Zijlstra
2012-03-20 10:18 ` Avi Kivity
2012-03-20 10:48 ` Peter Zijlstra
2012-03-20 10:52 ` Avi Kivity
2012-03-20 11:07 ` Peter Zijlstra
2012-03-20 11:48 ` Avi Kivity
2012-03-19 12:20 ` Peter Zijlstra
2012-03-19 12:24 ` Avi Kivity
2012-03-19 15:44 ` Avi Kivity
2012-03-19 13:40 ` Andrea Arcangeli
2012-03-19 20:06 ` Peter Zijlstra
2012-03-19 13:04 ` Andrea Arcangeli
2012-03-19 13:26 ` Peter Zijlstra
2012-03-19 13:57 ` Andrea Arcangeli
2012-03-19 14:06 ` Avi Kivity
2012-03-19 14:30 ` Andrea Arcangeli [this message]
2012-03-19 18:42 ` Peter Zijlstra
2012-03-20 22:18 ` Rik van Riel
2012-03-21 16:50 ` Andrea Arcangeli
2012-04-02 16:34 ` Pekka Enberg
2012-04-02 16:55 ` Rik van Riel
2012-04-02 16:54 ` Pekka Enberg
2012-04-02 17:12 ` Pekka Enberg
2012-04-02 17:23 ` Pekka Enberg
2012-03-19 14:07 ` Peter Zijlstra
2012-03-19 14:34 ` Andrea Arcangeli
2012-03-19 18:41 ` Peter Zijlstra
2012-03-19 19:13 ` Peter Zijlstra
2012-03-19 14:07 ` Andrea Arcangeli
2012-03-19 19:05 ` Peter Zijlstra
2012-03-19 13:26 ` Peter Zijlstra
2012-03-19 14:16 ` Andrea Arcangeli
2012-03-19 13:29 ` Peter Zijlstra
2012-03-19 14:19 ` Andrea Arcangeli
2012-03-19 13:39 ` Peter Zijlstra
2012-03-19 14:20 ` Andrea Arcangeli
2012-03-19 20:17 ` Christoph Lameter
2012-03-19 20:28 ` Ingo Molnar
2012-03-19 20:43 ` Christoph Lameter
2012-03-19 21:34 ` Ingo Molnar
2012-03-20 0:05 ` Linus Torvalds
2012-03-20 7:31 ` Ingo Molnar
2012-03-21 22:53 ` Nish Aravamudan
2012-03-22 9:45 ` Peter Zijlstra
2012-03-22 10:34 ` Ingo Molnar
2012-03-24 1:41 ` Nish Aravamudan
2012-03-26 11:42 ` Peter Zijlstra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120319143002.GQ24602@redhat.com \
--to=aarcange@redhat.com \
--cc=Lee.Schermerhorn@hp.com \
--cc=a.p.zijlstra@chello.nl \
--cc=akpm@linux-foundation.org \
--cc=avi@redhat.com \
--cc=bharata.rao@gmail.com \
--cc=danms@us.ibm.com \
--cc=efault@gmx.de \
--cc=hannes@cmpxchg.org \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@elte.hu \
--cc=paulmck@linux.vnet.ibm.com \
--cc=pjt@google.com \
--cc=riel@redhat.com \
--cc=suresh.b.siddha@intel.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).