Messages in this thread Patch in this message | | | Date | Wed, 27 Feb 2008 16:21:10 -0800 | From | "Paul E. McKenney" <> | Subject | [PATCH] Fix hibernate/resume in presence of PREEMPT_RCU and hotplug |
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Hello!
This fixes a oops encountered when doing hibernate/resume in presence of PREEMPT_RCU. The problem was that the code failed to disable preemption when accessing a per-CPU variable. This is OK when called from code that already has preemption disabled, but such is not the case from the suspend/resume code path.
Reported-by: Dave Young <hidave.darkstar@gmail.com> Tested-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> ---
rcupreempt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff -urpNa -X dontdiff linux-2.6.25-rc3/kernel/rcupreempt.c linux-2.6.25-rc3-rcuoffline/kernel/rcupreempt.c --- linux-2.6.25-rc3/kernel/rcupreempt.c 2008-02-26 16:58:43.000000000 -0800 +++ linux-2.6.25-rc3-rcuoffline/kernel/rcupreempt.c 2008-02-26 17:04:17.000000000 -0800 @@ -702,8 +702,9 @@ void rcu_offline_cpu(int cpu) * fix. */ + local_irq_save(flags); rdp = RCU_DATA_ME(); - spin_lock_irqsave(&rdp->lock, flags); + spin_lock(&rdp->lock); *rdp->nexttail = list; if (list) rdp->nexttail = tail;
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