mmotm 2010-03-09-19-15: Lot of scheduling while atomic warnings related to RCU
in [Kernel]
|
Prev: [PATCH 5/6] perf tools: Add missing bytes printed in hist_entry__fprintf
Next: [PATCH] firmware class: export nowait to userspace
From: Andi Kleen on 11 Mar 2010 17:40 > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: nhorman on 11 Mar 2010 19:20
On Thu, 11 Mar 2010 17:30:48 -0500, Andi Kleen wrote: > > 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 :) > Yes but the rcustring bits all got reverted, trashing my series :), so its all got to be rediffed anyway Neil > -Andi > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |