mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Borislav Petkov <bp@alien8.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>,
	Waiman Long <longman@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	SRINIVAS <srinivas.eeda@oracle.com>
Subject: Re: Question about qspinlock nest
Date: Fri, 11 Jan 2019 18:36:48 +0100	[thread overview]
Message-ID: <20190111173648.GH4729@zn.tnic> (raw)
In-Reply-To: <20190111091638.GK30894@hirez.programming.kicks-ass.net>

On Fri, Jan 11, 2019 at 10:16:38AM +0100, Peter Zijlstra wrote:
> > Not for debug exception, for MCE exception handler I found below two:
> > 
> > do_machine_check->mce_report_event->schedule_work

That has been the case at least since 2009. We probably never hit it or
I've never seen a deadlock caused by it.

> > do_machine_check->force_sig->force_sig_info

This does:

        ist_begin_non_atomic(regs);
        local_irq_enable();

before forcing the signal. And there's blurb above
ist_begin_non_atomic() why it is OK to schedule when the exception came
from usermode.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

  reply	other threads:[~2019-01-11 17:37 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-10  8:02 Zhenzhong Duan
2019-01-10 14:43 ` Waiman Long
2019-01-10 18:25   ` James Morse
2019-01-10 19:23     ` Waiman Long
2019-01-10 20:12     ` Peter Zijlstra
2019-01-11 18:32       ` James Morse
2019-01-14 13:16         ` Peter Zijlstra
2019-01-14 13:54           ` James Morse
2019-01-14 21:07             ` Waiman Long
2019-01-18 10:02             ` Peter Zijlstra
2019-01-18 10:24               ` Borislav Petkov
2019-01-18 14:50               ` Waiman Long
2019-01-18 20:06                 ` Peter Zijlstra
2019-01-18 21:30                   ` Waiman Long
     [not found]   ` <2eca6f60-3e8b-a389-27cb-8adbd9676607@oracle.com>
2019-01-11  9:16     ` Peter Zijlstra
2019-01-11 17:36       ` Borislav Petkov [this message]
2019-01-11 16:59     ` Waiman Long
2019-01-10 20:03 ` Peter Zijlstra
2019-01-14  9:25 Zhenzhong Duan

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=20190111173648.GH4729@zn.tnic \
    --to=bp@alien8.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=longman@redhat.com \
    --cc=peterz@infradead.org \
    --cc=srinivas.eeda@oracle.com \
    --cc=zhenzhong.duan@oracle.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

Powered by JetHome