linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Michal Hocko <mhocko@kernel.org>
To: Qian Cai <cai@lca.pw>
Cc: David Hildenbrand <david@redhat.com>,
	akpm@linux-foundation.org, sergey.senozhatsky.work@gmail.com,
	pmladek@suse.com, rostedt@goodmis.org, peterz@infradead.org,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH -next v5] mm/hotplug: silence a lockdep splat with printk()
Date: Mon, 20 Jan 2020 08:22:55 +0100	[thread overview]
Message-ID: <20200120072255.GB18451@dhcp22.suse.cz> (raw)
In-Reply-To: <587CD165-FAA4-4369-9F30-CB8F9C03F062@lca.pw>

On Fri 17-01-20 11:35:08, Qian Cai wrote:
> 
> 
> > On Jan 17, 2020, at 11:27 AM, David Hildenbrand <david@redhat.com> wrote:
> > 
> > the "int" should go onto the next line as well
> > [...]
> 
> Yes.
> 
> > apart from that looks good to me. I hope we won't have a whac-a-mole
> > with printk() (including WARN_ON() etc?) under the zone lock. This all
> > screams for a better fix.
> 
> WARN_ON() is normally not a concern. Once it happens here, we will
> figure out the reason why it happens in the first place and shut it
> off there instead.

It is very much the same concern as any other printk which might
deadlock. It is true this is WARN_ONCE so the likelyhood is much
smaller. But you know, probability is not going to help you if you are
unlucky ;)

-- 
Michal Hocko
SUSE Labs


      reply	other threads:[~2020-01-20  7:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-17 16:19 Qian Cai
2020-01-17 16:27 ` David Hildenbrand
2020-01-17 16:35   ` Qian Cai
2020-01-20  7:22     ` Michal Hocko [this message]

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=20200120072255.GB18451@dhcp22.suse.cz \
    --to=mhocko@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=cai@lca.pw \
    --cc=david@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=peterz@infradead.org \
    --cc=pmladek@suse.com \
    --cc=rostedt@goodmis.org \
    --cc=sergey.senozhatsky.work@gmail.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