diff options
| author |   Alexander Gordeev <agordeev@redhat.com> | 2012-03-09 14:59:59 +0100 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2012-03-09 17:19:09 +0100 |
| commit | 5234ffb9f74cfa8993d174782bc861dd9b7b5bfb (patch) | |
| tree | c3933cd6177cde81a99f0bcdadb333b1233e007d /kernel/irq/handle.c | |
| parent | genirq: No need to check IRQTF_DIED before stopping a thread handler (diff) | |
| download | wireguard-linux-5234ffb9f74cfa8993d174782bc861dd9b7b5bfb.tar.xz wireguard-linux-5234ffb9f74cfa8993d174782bc861dd9b7b5bfb.zip | |
genirq: Get rid of unnecessary IRQTF_DIED flag
Currently IRQTF_DIED flag is set when a IRQ thread handler calls do_exit()
But also PF_EXITING per process flag gets set when a thread exits. This
fix eliminates the duplicate by using PF_EXITING flag.
Also, there is a race condition in exit_irq_thread(). In case a thread's
bit is cleared in desc->threads_oneshot (and the IRQ line gets unmasked),
but before IRQTF_DIED flag is set, a new interrupt might come in and set
just cleared bit again, this time forever. This fix throws IRQTF_DIED flag
away, eliminating the race as a result.
[ tglx: Test THREAD_EXITING first as suggested by Oleg ]
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120309135958.GD2114@dhcp-26-207.brq.redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/irq/handle.c')
| -rw-r--r-- | kernel/irq/handle.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 470d08c82bbe..500aaf67c546 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -60,7 +60,7 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action) * device interrupt, so no irq storm is lurking. If the * RUNTHREAD bit is already set, nothing to do. */ - if (test_bit(IRQTF_DIED, &action->thread_flags) || + if ((action->thread->flags & PF_EXITING) || test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags)) return; |