linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: "Lukáš Czerner" <lczerner@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
	axboe@kernel.dk, jmoyer@redhat.com, Neil Brown <neilb@suse.de>
Subject: Re: [PATCH 1/2 v3] wait: add wait_event_lock_irq() interface
Date: Fri, 30 Nov 2012 12:13:08 -0800	[thread overview]
Message-ID: <20121130121308.54d66bfe.akpm@linux-foundation.org> (raw)
In-Reply-To: <alpine.LFD.2.00.1211301233320.8688@dhcp-1-104.brq.redhat.com>

On Fri, 30 Nov 2012 12:36:35 +0100 (CET)
Lukáš Czerner <lczerner@redhat.com> wrote:

> On Fri, 30 Nov 2012, Andrew Morton wrote:
> 
> > Date: Fri, 30 Nov 2012 02:48:42 -0800
> > From: Andrew Morton <akpm@linux-foundation.org>
> > To: Lukas Czerner <lczerner@redhat.com>
> > Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, axboe@kernel.dk,
> >     jmoyer@redhat.com, Neil Brown <neilb@suse.de>,
> >     David Howells <dhowells@redhat.com>, Ingo Molnar <mingo@elte.hu>,
> >     Peter Zijlstra <a.p.zijlstra@chello.nl>
> > Subject: Re: [PATCH 1/2 v3] wait: add wait_event_lock_irq() interface
> > 
> > On Fri, 30 Nov 2012 11:42:40 +0100 Lukas Czerner <lczerner@redhat.com> wrote:
> > 
> > > New wait_event{_interruptible}_lock_irq{_cmd} macros added. This commit
> > > moves the private wait_event_lock_irq() macro from MD to regular wait
> > > includes, introduces new macro wait_event_lock_irq_cmd() instead of using
> > > the old method with omitting cmd parameter which is ugly and makes a use
> > > of new macros in the MD. It also introduces the _interruptible_ variant.
> > > 
> > > The use of new interface is when one have a special lock to protect data
> > > structures used in the condition, or one also needs to invoke "cmd"
> > > before putting it to sleep.
> > > 
> > > All new macros are expected to be called with the lock taken. The lock
> > > is released before sleep and is reacquired afterwards. We will leave the
> > > macro with the lock held.
> > > 
> > > Note to DM: IMO this should also fix theoretical race on waitqueue while
> > > using simultaneously wait_event_lock_irq() and wait_event() because of
> > > lack of locking around current state setting and wait queue removal.
> > 
> > Does this fix the sparse warning which Fengguang just sent us?
> 
> Which report from Fengguang do you have in mind ? I do not see any
> on linux-kernel today.
> 
> /me going to see what spare reports
> 

On Fri, 30 Nov 2012 16:30:24 +0800
kbuild test robot <fengguang.wu@intel.com> wrote:

> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm
> head:   cfb65dadcd079ad4547407a1584bc6b96bd48bb3
> commit: 2b29cdb6f98c86a1da4ec5335d6247392b7c6551 [35/476] wait: add wait_event_lock_irq() interface
> 
> 
> sparse warnings:
> 
> + drivers/block/drbd/drbd_int.h:2339:9: sparse: preprocessor token __wait_event_lock_irq redefined
> include/linux/wait.h:554:9: this was the original definition
> + drivers/block/drbd/drbd_int.h:2358:9: sparse: preprocessor token wait_event_lock_irq redefined
> include/linux/wait.h:621:9: this was the original definition
> drivers/block/drbd/drbd_interval.h:12:63: sparse: dubious one-bit signed bitfield
> drivers/block/drbd/drbd_interval.h:13:22: sparse: dubious one-bit signed bitfield
> drivers/block/drbd/drbd_int.h:903:39: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1123:69: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1124:70: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1125:59: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1126:63: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1127:60: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1128:71: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1129:65: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1130:66: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1335:74: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1336:50: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1338:51: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1339:58: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1340:54: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1341:62: sparse: attribute 'require_context': unknown attribute
> drivers/block/drbd/drbd_int.h:1435:92: sparse: attribute 'require_context': unknown attribute

  reply	other threads:[~2012-11-30 20:13 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-30 10:42 [PATCH 1/2 v3] wait: add wait_event_lock_irq() interface Lukas Czerner
2012-11-30 10:42 ` [PATCH 2/2 v6] loop: Limit the number of requests in the bio list Lukas Czerner
2012-11-30 13:57   ` Jeff Moyer
2012-11-30 10:48 ` [PATCH 1/2 v3] wait: add wait_event_lock_irq() interface Andrew Morton
2012-11-30 11:36   ` Lukáš Czerner
2012-11-30 20:13     ` Andrew Morton [this message]
2012-12-03  9:21       ` Lukáš Czerner
2012-11-30 21:43 ` Andrew Morton

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=20121130121308.54d66bfe.akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=axboe@kernel.dk \
    --cc=jmoyer@redhat.com \
    --cc=lczerner@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-raid@vger.kernel.org \
    --cc=neilb@suse.de \
    /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).