From: Nathan Lynch <nathanl@linux.ibm.com>
To: Christophe Leroy <christophe.leroy@csgroup.eu>,
linuxppc-dev@lists.ozlabs.org
Cc: danielhb413@gmail.com, tyreld@linux.ibm.com,
ldufour@linux.ibm.com, aneesh.kumar@linux.ibm.com
Subject: Re: [PATCH 2/3] powerpc/cpuhp: BUG -> WARN conversion in offline path
Date: Mon, 20 Sep 2021 09:39:36 -0500 [thread overview]
Message-ID: <87mto7nwev.fsf@linux.ibm.com> (raw)
In-Reply-To: <47f36467-ae04-6472-741a-0851506a2d73@csgroup.eu>
Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 20/09/2021 à 15:55, Nathan Lynch a écrit :
>> If, due to bugs elsewhere, we get into unregister_cpu_online() with a CPU
>> that isn't marked hotpluggable, we can emit a warning and return an
>> appropriate error instead of crashing.
>
> Is it only a bug situation, or is it something that can happen in real
> life ?
>
> If it can happen in real life, kernels with panic_on_warn will still be
> impacted.
I only found this by inspection, and it can happen only due to a bug in
CPU device registration at boot. The flag must not be set if the
platform or CPU can't support going offline.
next prev parent reply other threads:[~2021-09-20 14:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-20 13:55 [PATCH 0/3] CPU DLPAR/hotplug for v5.16 Nathan Lynch
2021-09-20 13:55 ` [PATCH 1/3] powerpc/pseries/cpuhp: cache node corrections Nathan Lynch
2021-09-20 23:59 ` Daniel Henrique Barboza
2021-09-20 13:55 ` [PATCH 2/3] powerpc/cpuhp: BUG -> WARN conversion in offline path Nathan Lynch
2021-09-20 14:26 ` Christophe Leroy
2021-09-20 14:39 ` Nathan Lynch [this message]
2021-09-21 0:05 ` Daniel Henrique Barboza
2021-09-20 13:55 ` [PATCH 3/3] powerpc/pseries/cpuhp: delete add/remove_by_count code Nathan Lynch
2021-09-20 21:50 ` kernel test robot
2021-09-21 0:18 ` Daniel Henrique Barboza
2021-09-21 0:43 ` Nathan Lynch
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=87mto7nwev.fsf@linux.ibm.com \
--to=nathanl@linux.ibm.com \
--cc=aneesh.kumar@linux.ibm.com \
--cc=christophe.leroy@csgroup.eu \
--cc=danielhb413@gmail.com \
--cc=ldufour@linux.ibm.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=tyreld@linux.ibm.com \
/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;
as well as URLs for NNTP newsgroup(s).