From: Thomas Gleixner <tglx@kernel.org>
To: "Chang S. Bae" <chang.seok.bae@intel.com>, linux-kernel@vger.kernel.org
Cc: x86@kernel.org, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, peterz@infradead.org,
david.kaplan@amd.com
Subject: Re: [PATCH 1/7] stop_machine: Introduce stop_machine_nmi()
Date: Fri, 30 Jan 2026 11:02:33 +0100 [thread overview]
Message-ID: <87wm0zl8p2.ffs@tglx> (raw)
In-Reply-To: <00ad5958-dc5f-4d18-ad24-9de607912bf8@intel.com>
On Thu, Jan 29 2026 at 09:07, Chang S. Bae wrote:
> On 1/28/2026 12:02 AM, Thomas Gleixner wrote:
>> And this wants to become
>>
>> if (IS_ENABLED(CONFIG_STOMP_MACHINE_NMI) && msdata->use_nmi)
>> err = stop_this_cpu_nmi(msdata);
>> else
>> err = msdata->fn(msdata->data);
>
> Although that config option is very clear and makes tons of sense, the
> latter reads like a (silent) fallback path for a stop_machine_nmi()
> invocation with CONFIG_STOMP_MACHINE_NMI=n.
>
> Maybe this might be clear to reject the NMI option right away with
> something like:
>
> stop_machine_cpuslocked_nmi(...)
> {
> if (!IS_ENABLED(CONFIG_STOMP_MACHINE_NMI))
> return -EOPNOTSUPP;
> ...
> };
That function should not be exposed at all when the config switch is
off. Hide it behind #ifdef CONFIG...
It really should not be used in generic code at all.
Thanks,
tglx
next prev parent reply other threads:[~2026-01-30 10:02 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-25 1:42 [PATCH 0/7] x86/microcode: Refactor NMI-based rendezvous mechanism to stop-machine Chang S. Bae
2026-01-25 1:42 ` [PATCH 1/7] stop_machine: Introduce stop_machine_nmi() Chang S. Bae
2026-01-26 11:51 ` kernel test robot
2026-01-27 14:49 ` Borislav Petkov
2026-01-27 19:15 ` Chang S. Bae
2026-01-27 15:49 ` Borislav Petkov
2026-01-27 16:00 ` Kaplan, David
2026-01-27 20:49 ` Borislav Petkov
2026-01-28 1:31 ` Kaplan, David
2026-01-28 16:35 ` Borislav Petkov
2026-01-29 12:17 ` Borislav Petkov
2026-01-29 15:47 ` Chang S. Bae
2026-02-02 10:54 ` Borislav Petkov
2026-02-06 2:14 ` Chang S. Bae
2026-03-04 16:33 ` Borislav Petkov
2026-01-28 8:02 ` Thomas Gleixner
2026-01-29 17:07 ` Chang S. Bae
2026-01-30 10:02 ` Thomas Gleixner [this message]
2026-01-25 1:42 ` [PATCH 2/7] x86/apic: Implement self-NMI support Chang S. Bae
2026-01-28 8:05 ` Thomas Gleixner
2026-01-29 16:32 ` Chang S. Bae
2026-01-25 1:42 ` [PATCH 3/7] x86/nmi: Support stop_machine_nmi() handler Chang S. Bae
2026-01-25 1:42 ` [PATCH 4/7] x86/microcode: Distinguish NMI control path on stop-machine callback Chang S. Bae
2026-01-28 8:11 ` Thomas Gleixner
2026-01-29 16:32 ` Chang S. Bae
2026-01-25 1:42 ` [PATCH 5/7] x86/microcode: Use stop-machine NMI facility Chang S. Bae
2026-01-25 1:42 ` [PATCH 6/7] x86/nmi: Reference stop-machine static key for offline microcode handler Chang S. Bae
2026-01-25 1:42 ` [PATCH 7/7] x86/microcode: Remove microcode_nmi_handler_enable Chang S. Bae
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=87wm0zl8p2.ffs@tglx \
--to=tglx@kernel.org \
--cc=bp@alien8.de \
--cc=chang.seok.bae@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=david.kaplan@amd.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=x86@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox