linux-kernel - Re: [PATCH v2] x86/power: Fix 'nosmt' vs. hibernation triple fault during resume

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Date:   Wed, 29 May 2019 20:02:47 +0200 (CEST)
From:   Jiri Kosina <jikos@...nel.org>
To:     Josh Poimboeuf <jpoimboe@...hat.com>
cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Pavel Machek <pavel@....cz>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Peter Zijlstra <peterz@...radead.org>, x86@...nel.org,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] x86/power: Fix 'nosmt' vs. hibernation triple fault
 during resume

On Wed, 29 May 2019, Jiri Kosina wrote:

> The target kernel only onlines the CPUs which were online at the time of 
> hibernation (and are therefore in frozen_cpus mask).

Hm, there is a catch though. After resume, the SMT siblings are now in hlt 
instead of mwait.

Which means that the resumed kernel has to do one more online/offline 
cycle for them, to push them to mwait again.

Bah.

I'll send v3 shortly, so please don't apply v2 just yet.

-- 
Jiri Kosina
SUSE Labs