From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>,
Rik van Riel <riel@surriel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Michael Ellerman <mpe@ellerman.id.au>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Benjamin Herrenschmidt <benh@au1.ibm.com>
Subject: Re: [PATCH 2/2] sched/topology: Expose numa_mask set/clear functions to arch
Date: Fri, 31 Aug 2018 04:53:50 -0700 [thread overview]
Message-ID: <20180831115350.GC8437@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180831112639.GA24142@hirez.programming.kicks-ass.net>
* Peter Zijlstra <peterz@infradead.org> [2018-08-31 13:26:39]:
> On Fri, Aug 31, 2018 at 01:12:53PM +0200, Peter Zijlstra wrote:
> > NAK, not until you've fixed every cpu_to_node() user in the kernel to
> > deal with that mask changing.
>
> Also, what happens if userspace reads that information; uses libnuma and
> then you go and shift the world underneath their feet?
>
> > This is absolutely insane.
>
The topology events are suppose to be very rare.
>From whatever small experiments I have done till now, unless tasks are
bound to both cpu and memory, they seem to be coping well with topology
updates. I know things weren't optimal after a topology change but they
worked. Now after 051f3ca02e46 "Introduce NUMA identity node sched
domain", systems stall. I am only exploring at ways to keep them working
as much as they were before that commit.
--
Thanks and Regards
Srikar Dronamraju
WARNING: multiple messages have this Message-ID (diff)
From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>,
Rik van Riel <riel@surriel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Michael Ellerman <mpe@ellerman.id.au>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Benjamin Herrenschmidt <benh@au1.ibm.com>
Subject: Re: [PATCH 2/2] sched/topology: Expose numa_mask set/clear functions to arch
Date: Fri, 31 Aug 2018 04:53:50 -0700 [thread overview]
Message-ID: <20180831115350.GC8437@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180831112639.GA24142@hirez.programming.kicks-ass.net>
* Peter Zijlstra <peterz@infradead.org> [2018-08-31 13:26:39]:
> On Fri, Aug 31, 2018 at 01:12:53PM +0200, Peter Zijlstra wrote:
> > NAK, not until you've fixed every cpu_to_node() user in the kernel to
> > deal with that mask changing.
>
> Also, what happens if userspace reads that information; uses libnuma and
> then you go and shift the world underneath their feet?
>
> > This is absolutely insane.
>
The topology events are suppose to be very rare.
From whatever small experiments I have done till now, unless tasks are
bound to both cpu and memory, they seem to be coping well with topology
updates. I know things weren't optimal after a topology change but they
worked. Now after 051f3ca02e46 "Introduce NUMA identity node sched
domain", systems stall. I am only exploring at ways to keep them working
as much as they were before that commit.
--
Thanks and Regards
Srikar Dronamraju
next prev parent reply other threads:[~2018-08-31 12:55 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <reply-to=<20180808081942.GA37418@linux.vnet.ibm.com>
2018-08-10 17:00 ` [PATCH 1/2] sched/topology: Set correct numa topology type Srikar Dronamraju
2018-08-10 17:00 ` [PATCH 2/2] sched/topology: Expose numa_mask set/clear functions to arch Srikar Dronamraju
2018-08-29 8:02 ` Peter Zijlstra
2018-08-31 10:27 ` Srikar Dronamraju
2018-08-31 11:12 ` Peter Zijlstra
2018-08-31 11:26 ` Peter Zijlstra
2018-08-31 11:53 ` Srikar Dronamraju [this message]
2018-08-31 11:53 ` Srikar Dronamraju
2018-08-31 12:05 ` Peter Zijlstra
2018-08-31 12:08 ` Peter Zijlstra
2018-08-21 11:02 ` [PATCH 1/2] sched/topology: Set correct numa topology type Srikar Dronamraju
2018-08-21 13:59 ` Peter Zijlstra
2018-09-10 10:06 ` [tip:sched/core] sched/topology: Set correct NUMA " tip-bot for Srikar Dronamraju
2018-08-08 7:09 [PATCH] sched/topology: Use Identity node only if required Srikar Dronamraju
2018-08-08 7:58 ` Peter Zijlstra
2018-08-08 8:19 ` Srikar Dronamraju
2018-08-08 8:43 ` Peter Zijlstra
2018-08-08 9:30 ` Peter Zijlstra
2018-08-10 16:45 ` Srikar Dronamraju
2018-08-29 8:43 ` Peter Zijlstra
2018-08-29 8:57 ` Peter Zijlstra
2018-08-31 10:22 ` Srikar Dronamraju
2018-08-31 10:22 ` Srikar Dronamraju
2018-08-31 10:41 ` Peter Zijlstra
2018-08-31 11:26 ` Srikar Dronamraju
2018-08-31 12:06 ` 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=20180831115350.GC8437@linux.vnet.ibm.com \
--to=srikar@linux.vnet.ibm.com \
--cc=benh@au1.ibm.com \
--cc=heiko.carstens@de.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mgorman@techsingularity.net \
--cc=mingo@kernel.org \
--cc=mpe@ellerman.id.au \
--cc=peterz@infradead.org \
--cc=riel@surriel.com \
--cc=suravee.suthikulpanit@amd.com \
--cc=tglx@linutronix.de \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.