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 11:54 UTC|newest]
Thread overview: 24+ 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 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 10:41 ` Peter Zijlstra
2018-08-31 11:26 ` Srikar Dronamraju
2018-08-31 12:06 ` Peter Zijlstra
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