Commit 5d60d3e7 authored Sep 24, 2013 by Frederic Weisbecker

irq: Improve a bit softirq debugging



do_softirq() has a debug check that verifies that it is not nesting
on softirqs processing, nor miscounting the softirq part of the preempt
count.

But making sure that softirqs processing don't nest is actually a more
generic concern that applies to any caller of __do_softirq().

Do take it one step further and generalize that debug check to
any softirq processing.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Andrew Morton <akpm@linux-foundation.org>

parent be6e1016

kernel/softirq.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -133,7 +133,6 @@ EXPORT_SYMBOL(local_bh_disable);

		static void __local_bh_enable(unsigned int cnt)
		{
		WARN_ON_ONCE(in_irq());
		WARN_ON_ONCE(!irqs_disabled());

		if (softirq_count() == cnt)
		@@ -148,6 +147,7 @@ static void __local_bh_enable(unsigned int cnt)
		*/
		void _local_bh_enable(void)
		{
		WARN_ON_ONCE(in_irq());
		__local_bh_enable(SOFTIRQ_DISABLE_OFFSET);
		}

		@@ -279,6 +279,7 @@ restart:

		account_irq_exit_time(current);
		__local_bh_enable(SOFTIRQ_OFFSET);
		WARN_ON_ONCE(in_interrupt());
		tsk_restore_flags(current, old_flags, PF_MEMALLOC);
		}

		@@ -299,7 +300,6 @@ asmlinkage void do_softirq(void)
		if (pending)
		do_softirq_own_stack();

		WARN_ON_ONCE(softirq_count());
		local_irq_restore(flags);
		}

Admin message