public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Andrea Arcangeli <aarcange@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Avi Kivity <avi@redhat.com>, kvm <kvm@vger.kernel.org>,
	Ingo Molnar <mingo@elte.hu>
Subject: Re: mmu_notifiers: turn off lockdep around mm_take_all_locks
Date: Wed, 8 Jul 2009 01:30:14 +0200	[thread overview]
Message-ID: <20090707233014.GQ11736@random.random> (raw)
In-Reply-To: <1246996825.5197.34.camel@laptop>

On Tue, Jul 07, 2009 at 10:00:25PM +0200, Peter Zijlstra wrote:
> It does feel slightly weird to explicitly overflow that preempt count
> though.

That is actually fixable there without adding more bits to preempt
count, just call a global preempt_disable after lockdep_off and call a
spinlock version that doesn't preempt_disable (or preempt_enable after
every spin_lock..).

> But sure, something like the below would disable lockdep for the
> critical bits.. really don't like it though, but the alternative is
> modifying the rmap locking and I don't like that either :/

Once we add that, I guess we can also remove the spin_lock_nest_lock.

      reply	other threads:[~2009-07-07 23:30 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-07 18:06 mmu_notifiers: turn off lockdep around mm_take_all_locks Marcelo Tosatti
2009-07-07 18:15 ` Peter Zijlstra
2009-07-07 18:18   ` Avi Kivity
2009-07-07 18:37     ` Marcelo Tosatti
2009-07-07 19:04       ` Peter Zijlstra
2009-07-07 19:25         ` Linus Torvalds
2009-07-07 20:00           ` Peter Zijlstra
2009-07-07 23:30             ` Andrea Arcangeli [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=20090707233014.GQ11736@random.random \
    --to=aarcange@redhat.com \
    --cc=avi@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=mtosatti@redhat.com \
    --cc=peterz@infradead.org \
    --cc=torvalds@linux-foundation.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