LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Christoph Lameter <clameter@sgi.com>
To: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>,
	Benjamin Gilbert <bgilbert@cs.cmu.edu>,
	linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
	Gautham shenoy <ego@in.ibm.com>, Andrew Morton <akpm@osdl.org>,
	Pekka Enberg <penberg@cs.helsinki.fi>
Subject: Re: [patch -mm] slab: use CPU_LOCK_[ACQUIRE|RELEASE]
Date: Wed, 10 Jan 2007 10:20:28 -0800 (PST)	[thread overview]
Message-ID: <Pine.LNX.4.64.0701101012460.21379@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20070109150615.GF9563@osiris.boeblingen.de.ibm.com>

On Tue, 9 Jan 2007, Heiko Carstens wrote:

> -	case CPU_UP_PREPARE:
> +	case CPU_LOCK_ACQUIRE:
>  		mutex_lock(&cache_chain_mutex);
> +		break;

I have got a bad feeling about upcoming deadlock problems when looking at 
the mutex_lock / unlock code in cpuup_callback in slab.c. Branches 
that just obtain a lock or release a lock? I hope there is some 
control of  what happens between lock acquisition and release?

You are aware that this lock is taken for cache shrinking/destroy, tuning 
of cpu cache sizes, proc output and cache creation? Any of those run on 
the same processor should cause a deadlock.

  reply	other threads:[~2007-01-10 18:21 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-08 17:07 Failure to release lock after CPU hot-unplug canceled Benjamin Gilbert
2007-01-09 12:17 ` Heiko Carstens
2007-01-09 12:27   ` Srivatsa Vaddagiri
2007-01-09 15:03     ` Heiko Carstens
2007-01-09 15:05       ` [patch -mm] call cpu_chain with CPU_DOWN_FAILED if CPU_DOWN_PREPARE failed Heiko Carstens
2007-01-09 15:06       ` [patch -mm] slab: use CPU_LOCK_[ACQUIRE|RELEASE] Heiko Carstens
2007-01-10 18:20         ` Christoph Lameter [this message]
2007-01-11  2:30           ` Srivatsa Vaddagiri
2007-01-09 16:34       ` Failure to release lock after CPU hot-unplug canceled Benjamin Gilbert

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=Pine.LNX.4.64.0701101012460.21379@schroedinger.engr.sgi.com \
    --to=clameter@sgi.com \
    --cc=akpm@osdl.org \
    --cc=bgilbert@cs.cmu.edu \
    --cc=ego@in.ibm.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=penberg@cs.helsinki.fi \
    --cc=vatsa@in.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).