From: Ingo Molnar <mingo@elte.hu>
To: Roland Dreier <rdreier@cisco.com>
Cc: akpm@osdl.org, Arjan van de Ven <arjan@infradead.org>,
Zach Brown <zach.brown@oracle.com>,
openib-general@openib.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Convert idr's internal locking to _irqsave variant
Date: Wed, 12 Jul 2006 23:14:43 +0200 [thread overview]
Message-ID: <20060712211443.GA10944@elte.hu> (raw)
In-Reply-To: <adaveq2v9gn.fsf@cisco.com>
* Roland Dreier <rdreier@cisco.com> wrote:
> Currently, the code in lib/idr.c uses a bare spin_lock(&idp->lock) to
> do internal locking. This is a nasty trap for code that might call
> idr functions from different contexts; for example, it seems perfectly
> reasonable to call idr_get_new() from process context and idr_remove()
> from interrupt context -- but with the current locking this would lead
> to a potential deadlock.
>
> The simplest fix for this is to just convert the idr locking to use
> spin_lock_irqsave().
>
> In particular, this fixes a very complicated locking issue detected by
> lockdep, involving the ib_ipoib driver's priv->lock and
> dev->_xmit_lock, which get involved with the ib_sa module's
> query_idr.lock.
>
> Cc: Arjan van de Ven <arjan@infradead.org>
> Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Ingo Molnar <mingo@elte.hu>
Ingo
next prev parent reply other threads:[~2006-07-12 21:20 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-11 20:10 ipoib lockdep warning Zach Brown
2006-07-11 21:16 ` Michael S. Tsirkin
2006-07-11 21:40 ` Sean Hefty
2006-07-11 21:50 ` [openib-general] " Zach Brown
2006-07-11 22:54 ` Roland Dreier
2006-07-11 23:27 ` Zach Brown
2006-07-11 23:43 ` Roland Dreier
2006-07-11 23:53 ` Zach Brown
2006-07-12 0:06 ` Roland Dreier
2006-07-12 9:38 ` Ingo Molnar
2006-07-12 11:09 ` Michael S. Tsirkin
2006-07-12 16:31 ` [openib-general] " Sean Hefty
2006-07-12 18:56 ` Roland Dreier
2006-07-13 15:55 ` [PATCH] IB/core: use correct gfp_mask in sa_query Michael S. Tsirkin
2006-07-12 19:06 ` [openib-general] ipoib lockdep warning Roland Dreier
2006-07-12 20:45 ` [PATCH] Convert idr's internal locking to _irqsave variant Roland Dreier
2006-07-12 21:14 ` Ingo Molnar [this message]
2006-07-13 1:30 ` Andrew Morton
2006-07-13 15:42 ` Roland Dreier
2006-07-13 20:54 ` Andrew Morton
2006-07-13 21:03 ` Roland Dreier
2006-07-13 21:05 ` Arjan van de Ven
2006-07-14 0:18 ` Roland Dreier
2006-07-14 6:20 ` Arjan van de Ven
2006-07-13 21:43 ` Andrew Morton
2006-07-14 1:08 ` Roland Dreier
2006-07-14 1:18 ` Andrew Morton
2006-07-14 1:30 ` Andrew Morton
2006-07-17 15:57 ` Roland Dreier
2006-07-12 2:33 ` [openib-general] ipoib lockdep warning Roland Dreier
2006-07-12 6:49 ` Arjan van de Ven
2006-07-12 19:01 ` Roland Dreier
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=20060712211443.GA10944@elte.hu \
--to=mingo@elte.hu \
--cc=akpm@osdl.org \
--cc=arjan@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=openib-general@openib.org \
--cc=rdreier@cisco.com \
--cc=zach.brown@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
all inboxes | Powered by JetHome®