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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2013-02-22 00:05:07 +0100 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2013-02-22 00:05:07 +0100 |
| commit | 4d4c4e24cf48400a24d33feffc7cca4f4e8cabe1 (patch) | |
| tree | b1d4862302c3cc56a10bed9605c9e9b0379a234b | |
| parent | af7bdbafe3812af406ce07631effd2b96aae2dba (diff) | |
| download | blackbird-op-linux-4d4c4e24cf48400a24d33feffc7cca4f4e8cabe1.tar.gz blackbird-op-linux-4d4c4e24cf48400a24d33feffc7cca4f4e8cabe1.zip | |
irq: Remove IRQ_EXIT_OFFSET workaround
The IRQ_EXIT_OFFSET trick was used to make sure the irq
doesn't get preempted after we substract the HARDIRQ_OFFSET
until we are entirely done with any code in irq_exit().
This workaround was necessary because some archs may call
irq_exit() with irqs enabled and there is still some code
in the end of this function that is not covered by the
HARDIRQ_OFFSET but want to stay non-preemptible.
Now that irq are always disabled in irq_exit(), the whole code
is guaranteed not to be preempted. We can thus remove this hack.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | include/linux/hardirq.h | 2 | ||||
| -rw-r--r-- | kernel/softirq.c | 3 |
2 files changed, 1 insertions, 4 deletions
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 29eb805ea4a6..c1d6555d2567 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -118,10 +118,8 @@ #ifdef CONFIG_PREEMPT_COUNT # define preemptible() (preempt_count() == 0 && !irqs_disabled()) -# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1) #else # define preemptible() 0 -# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET #endif #if defined(CONFIG_SMP) || defined(CONFIG_GENERIC_HARDIRQS) diff --git a/kernel/softirq.c b/kernel/softirq.c index 24a921bcf04f..f42ff97e1f8f 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -343,7 +343,7 @@ void irq_exit(void) account_irq_exit_time(current); trace_hardirq_exit(); - sub_preempt_count(IRQ_EXIT_OFFSET); + sub_preempt_count(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); @@ -353,7 +353,6 @@ void irq_exit(void) tick_nohz_irq_exit(); #endif rcu_irq_exit(); - sched_preempt_enable_no_resched(); #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED local_irq_restore(flags); #endif |
