Re: Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c

From: Bruno Wolff III <bruno@wolff.to>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Josh Boyer <jwboyer@redhat.com>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c
Date: Fri, 18 Jul 2014 08:01:26 -0500	[thread overview]
Message-ID: <20140718130126.GA2401@wolff.to> (raw)
In-Reply-To: <20140718101633.GP9918@twins.programming.kicks-ass.net>

On Fri, Jul 18, 2014 at 12:16:33 +0200,
  Peter Zijlstra <peterz@infradead.org> wrote:
>So it looks like the actual domain tree is broken, and not what we
>assumed it was.
>
>Could I bother you to run with the below instead? It should also print
>out the sched domain masks so we don't need to guess about them.

The full dmesg output is at:
https://bugzilla.kernel.org/attachment.cgi?id=143381

>(make sure you have CONFIG_SCHED_DEBUG=y otherwise it will not build)
>
>> I also booted with early printk=keepsched_debug as requested by Dietmar.
>
>can you make that: sched_debug ?

I think I've fixed that.

I think the part you are most interested in contains the following:
[    0.252280] smpboot: Total of 4 processors activated (21438.11 BogoMIPS)
[    0.253058] __sdt_alloc: allocated f255b020 with cpus: 
[    0.253146] __sdt_alloc: allocated f255b0e0 with cpus: 
[    0.253227] __sdt_alloc: allocated f255b120 with cpus: 
[    0.253308] __sdt_alloc: allocated f255b160 with cpus: 
[    0.253390] __sdt_alloc: allocated f255b1a0 with cpus: 
[    0.253471] __sdt_alloc: allocated f255b1e0 with cpus: 
[    0.253551] __sdt_alloc: allocated f255b220 with cpus: 
[    0.253632] __sdt_alloc: allocated f255b260 with cpus: 
[    0.254009] __sdt_alloc: allocated f255b2a0 with cpus: 
[    0.254092] __sdt_alloc: allocated f255b2e0 with cpus: 
[    0.254181] __sdt_alloc: allocated f255b320 with cpus: 
[    0.254262] __sdt_alloc: allocated f255b360 with cpus: 
[    0.254350] build_sched_domain: cpu: 0 level: SMT cpu_map: 0-3 tl->mask: 0,2
[    0.254433] build_sched_domain: cpu: 0 level: MC cpu_map: 0-3 tl->mask: 0
[    0.254516] build_sched_domain: cpu: 0 level: DIE cpu_map: 0-3 tl->mask: 0-3
[    0.254600] build_sched_domain: cpu: 1 level: SMT cpu_map: 0-3 tl->mask: 1,3
[    0.254683] build_sched_domain: cpu: 1 level: MC cpu_map: 0-3 tl->mask: 1
[    0.254766] build_sched_domain: cpu: 1 level: DIE cpu_map: 0-3 tl->mask: 0-3
[    0.254850] build_sched_domain: cpu: 2 level: SMT cpu_map: 0-3 tl->mask: 0,2
[    0.254932] build_sched_domain: cpu: 2 level: MC cpu_map: 0-3 tl->mask: 2
[    0.255005] build_sched_domain: cpu: 2 level: DIE cpu_map: 0-3 tl->mask: 0-3
[    0.255091] build_sched_domain: cpu: 3 level: SMT cpu_map: 0-3 tl->mask: 1,3
[    0.255176] build_sched_domain: cpu: 3 level: MC cpu_map: 0-3 tl->mask: 3
[    0.255260] build_sched_domain: cpu: 3 level: DIE cpu_map: 0-3 tl->mask: 0-3
[    0.256006] build_sched_groups: got group f255b020 with cpus: 
[    0.256089] build_sched_groups: got group f255b120 with cpus: 
[    0.256171] build_sched_groups: got group f255b1a0 with cpus: 
[    0.256252] build_sched_groups: got group f255b2a0 with cpus: 
[    0.256333] build_sched_groups: got group f255b2e0 with cpus: 
[    0.256414] build_sched_groups: got group f255b320 with cpus: 
[    0.256495] build_sched_groups: got group f255b360 with cpus: 
[    0.256576] build_sched_groups: got group f255b0e0 with cpus: 
[    0.256657] build_sched_groups: got group f255b160 with cpus: 
[    0.256740] build_sched_groups: got group f255b1e0 with cpus: 
[    0.256821] build_sched_groups: FAIL
[    0.257004] build_sched_groups: got group f255b1a0 with cpus: 0
[    0.257087] build_sched_groups: FAIL
[    0.257167] build_sched_groups: got group f255b1e0 with cpus: 1