From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] markers: fix unregister bug and reenter bug
Date: Mon, 29 Sep 2008 11:03:20 -0400 [thread overview]
Message-ID: <20080929150320.GA11245@Krystal> (raw)
In-Reply-To: <48E08B05.7030802@cn.fujitsu.com>
Hi Lai,
I'll have to nack this fix :
One fix I already posted makes sure every marker unregister callers call
synchronize_sched() _at some point_ before module unload. It thus makes
sure we can do batch unregistration without doing multiple
synchronize_sched calls.
Also, there is no need to do the synchronize_sched with the marker mutex
held. call_rcu_sched takes care of making sure the previous quiescent
state is over before calling kfree. This means that when we return from
the register/unregister functions, there may still be markers "in
flight" using the old markers. Again, why would it be a problem ?
Thanks,
Mathieu
P.S. : I'll send along the patches I am referring to. Ingo, those should
probably be merged if they are not in -tip already.
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
next prev parent reply other threads:[~2008-09-29 15:03 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-29 8:00 [PATCH] markers: fix unregister bug and reenter bug Lai Jiangshan
2008-09-29 8:27 ` Ingo Molnar
2008-09-29 15:03 ` Mathieu Desnoyers
2008-09-29 15:05 ` [PATCH] Markers : marker_synchronize_unregister() Mathieu Desnoyers
2008-09-30 1:47 ` Lai Jiangshan
[not found] ` <20081002235650.43ca075c.akpm@linux-foundation.org>
2008-10-03 15:52 ` [PATCH] Markers synchronize unregister static inline Mathieu Desnoyers
2008-10-03 17:31 ` Ingo Molnar
2008-09-29 15:06 ` [PATCH] RCU read sched Mathieu Desnoyers
2008-09-30 10:08 ` Ingo Molnar
2008-09-30 13:10 ` Paul E. McKenney
2008-09-30 13:10 ` Paul E. McKenney
2008-09-29 15:08 ` [PATCH] Markers use rcu_read_lock_sched() Mathieu Desnoyers
2008-09-30 10:13 ` Ingo Molnar
2008-09-29 15:09 ` [PATCH] Markers : probe example fix teardown Mathieu Desnoyers
2008-09-29 15:10 ` [PATCH] Markers : documentation " Mathieu Desnoyers
2008-09-29 15:11 ` [PATCH] sputrace : use marker_synchronize_unregister() Mathieu Desnoyers
2008-09-29 15:13 ` Christoph Hellwig
2008-09-30 0:28 ` Jeremy Kerr
2008-09-30 9:55 ` Ingo Molnar
2008-09-30 11:22 ` [Cbe-oss-dev] " Jeremy Kerr
2008-09-30 11:30 ` Ingo Molnar
2008-09-30 11:34 ` Jeremy Kerr
2008-09-29 15:03 ` Mathieu Desnoyers [this message]
2008-09-30 1:40 ` [PATCH] markers: fix unregister bug and reenter bug Lai Jiangshan
2008-09-30 3:38 ` Mathieu Desnoyers
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=20080929150320.GA11245@Krystal \
--to=mathieu.desnoyers@polymtl.ca \
--cc=akpm@linux-foundation.org \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=paulmck@linux.vnet.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