From: Igor Mammedov <imammedo@redhat.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org, drjones@redhat.com,
toshi.kani@hp.com, prarit@redhat.com,
kirill.shutemov@linux.intel.com, JBeulich@suse.com,
peterz@infradead.org, paul.gortmaker@windriver.com,
seiji.aguchi@hds.com, bp@suse.de, hpa@zytor.com,
mingo@redhat.com, x86@kernel.org, tglx@linutronix.de,
riel@redhat.com
Subject: Re: [PATCH] abort secondary CPU bring-up gracefully if do_boot_cpu timed out on cpu_callin_mask
Date: Thu, 6 Mar 2014 10:10:09 +0100 [thread overview]
Message-ID: <20140306101009.34ba6c3c@nial.usersys.redhat.com> (raw)
In-Reply-To: <20140306070832.GA1277@gmail.com>
On Thu, 6 Mar 2014 08:08:32 +0100
Ingo Molnar <mingo@kernel.org> wrote:
>
> * Igor Mammedov <imammedo@redhat.com> wrote:
>
> > Master CPU may timeout before cpu_callin_mask is set and cancel
> > booting CPU, but being onlined CPU still continues to boot, sets
> > cpu_active_mask (CPU_STARTING notifiers) and spins in
> > check_tsc_sync_target() for master cpu to arrive. Following attempt
> > to online another cpu hangs in stop_machine, initiated from here:
>
> The changelog needs to prominently contain a description of the
> practical relevance of this patch: has the hang triggered on any
> system and under what circumstances, and did the patch resolve the
> hang, etc.?
Hang is observed on virtual machines during CPU hotplug,
especially in big guests with many CPUs. (It happens more
often if host is over-committed).
Similar patch is carried in RHEL6 since 2012 and it fixes
issue there, when applied to upstream kernel it also fixes
issue.
>
> Thanks,
>
> Ingo
Thanks,
Igor.
next prev parent reply other threads:[~2014-03-06 10:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 14:45 Igor Mammedov
2014-03-06 7:08 ` Ingo Molnar
2014-03-06 9:10 ` Igor Mammedov [this message]
2014-03-06 13:32 ` Ingo Molnar
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=20140306101009.34ba6c3c@nial.usersys.redhat.com \
--to=imammedo@redhat.com \
--cc=JBeulich@suse.com \
--cc=bp@suse.de \
--cc=drjones@redhat.com \
--cc=hpa@zytor.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=paul.gortmaker@windriver.com \
--cc=peterz@infradead.org \
--cc=prarit@redhat.com \
--cc=riel@redhat.com \
--cc=seiji.aguchi@hds.com \
--cc=tglx@linutronix.de \
--cc=toshi.kani@hp.com \
--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
Powered by JetHome