[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <YzRyaLRqWd6YSgeJ@zn.tnic>
Date: Wed, 28 Sep 2022 18:12:24 +0200
From: Borislav Petkov <bp@...en8.de>
To: Juergen Gross <jgross@...e.com>
Cc: xen-devel@...ts.xenproject.org, x86@...nel.org,
linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH v3 08/10] x86/mtrr: let cache_aps_delayed_init replace
mtrr_aps_delayed_init
On Wed, Sep 28, 2022 at 03:43:56PM +0200, Juergen Gross wrote:
> Would you feel better with adding a new enum member CPUHP_AP_CACHECTRL_ONLINE?
>
> This would avoid a possible source of failure during resume in case no slot
> for CPUHP_AP_ONLINE_DYN is found (quite improbable, but in theory possible).
Let's keep that in the bag for the time when we get to cross that bridge.
> You wouldn't want to do that there, as there are multiple places where
> pm_sleep_enable_secondary_cpus() is being called.
We want all of them, I'd say. They're all some sort of suspend AFAICT.
But yes, if we get to do it, that would need a proper audit.
> Additionally not all cases are coming in via
> pm_sleep_enable_secondary_cpus(), as there is e.g. a call of
> suspend_enable_secondary_cpus() from kernel_kexec(), which wants to
> have the same handling.
Which means, more hairy.
> arch_thaw_secondary_cpus_begin() and arch_thaw_secondary_cpus_end() are
> the functions to mark start and end of the special region where the
> delayed MTRR setup should happen.
Yap, it seems like the best solution at the moment. Want me to do a
proper patch and test it on real hw?
:-)
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
Powered by blists - more mailing lists