From: Andi Kleen <andi@firstfloor.org>
To: Neil Horman <nhorman@tuxdriver.com>
Cc: Mel Gorman <mel@csn.ul.ie>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
Andi Kleen <andi@firstfloor.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: mmotm 2010-03-09-19-15: Lot of scheduling while atomic warnings related to RCU
Date: Thu, 11 Mar 2010 23:30:48 +0100 [thread overview]
Message-ID: <20100311223048.GI20695@one.firstfloor.org> (raw)
In-Reply-To: <20100310203242.GC3770@hmsreliant.think-freely.org>
> a/lib/kobject_uevent.c~sysctl-fix-up-remaining-references-to-uevent_helper-fix
> +++ a/lib/kobject_uevent.c
> @@ -273,10 +273,11 @@ int kobject_uevent_env(struct kobject *k
> #endif
>
> /* call uevent_helper, usually only enabled during early boot */
> + rcu_read_lock();
> helper = rcu_dereference(uevent_helper);
> if (helper[0])
> retval = uevent_call_helper(subsystem, env);
> -
> + rcu_read_unlock();
> exit:
The data actually has to be copied, there's a helper for this in rcustring.
I'll try to send a patch later.
> loads/unloads while changing uevent_helper. Anywho, should be easy to fix,
> Mel, can you modify the code to copy helper to a private variable, then unlock
> the rcu read side prior to calling uevent_call_helper? I imagine that would be
Yes, except rcustring already has a helper for that :)
-Andi
next prev parent reply other threads:[~2010-03-11 22:30 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-10 3:16 mmotm 2010-03-09-19-15 uploaded akpm
2010-03-10 19:43 ` [PATCH -mmotm] leds: fix net5501 kconfig Randy Dunlap
2010-03-10 19:57 ` mmotm 2010-03-09-19-15: Lot of scheduling while atomic warnings related to RCU Mel Gorman
2010-03-10 20:21 ` Andrew Morton
2010-03-10 20:34 ` Mel Gorman
2010-03-10 20:32 ` Neil Horman
2010-03-11 22:30 ` Andi Kleen [this message]
2010-03-12 0:09 ` nhorman
2010-03-12 11:46 ` Mel Gorman
2010-03-12 15:29 ` Neil Horman
2010-03-12 15:41 ` Mel Gorman
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