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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-07-02 18:08:42 +0400
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-07-02 22:39:19 +0400
commitcba6d0d64ee53772b285d0c0c288deefbeaf7775 (patch)
treeb2d3de62d15a77d23708c1af6f188c86f0d87fb9 /arch/um
parent6887a4131da3adaab011613776d865f4bcfb5678 (diff)
downloadlinux-cba6d0d64ee53772b285d0c0c288deefbeaf7775.tar.xz
Revert "rcu: Move PREEMPT_RCU preemption to switch_to() invocation"
This reverts commit 616c310e83b872024271c915c1b9ab505b9efad9. (Move PREEMPT_RCU preemption to switch_to() invocation). Testing by Sasha Levin <levinsasha928@gmail.com> showed that this can result in deadlock due to invoking the scheduler when one of the runqueue locks is held. Because this commit was simply a performance optimization, revert it. Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Sasha Levin <levinsasha928@gmail.com>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/drivers/mconsole_kern.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 88e466b159dc..43b39d61b538 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -705,7 +705,6 @@ static void stack_proc(void *arg)
struct task_struct *from = current, *to = arg;
to->thread.saved_task = from;
- rcu_switch_from(from);
switch_to(from, to, from);
}