[PATCH 1/1] powerpc: Remove redundant xics badness warning

Brian King brking at linux.vnet.ibm.com
Thu Jul 15 04:48:13 EST 2010

While testing cpu offlining, we are regularly seeing the WARN_ON go off
in xics_ipi_dispatch. It can occur when an IPI gets sent to the CPU while
it is going offline. There is already a similar WARN_ON in the handlers
is not needed in that path. The debugger handler handles this case by
simply ignoring IPIs for offline CPUs, so no warning is needed there.
And the reschedule IPI, which is what is occurring in our test environment,
can be safely ignored, so we can simply remove the WARN_ON from xics_ipi_dispatch.

Signed-off-by: Brian King <brking at linux.vnet.ibm.com>

 arch/powerpc/platforms/pseries/xics.c |    2 --
 1 file changed, 2 deletions(-)

diff -puN arch/powerpc/platforms/pseries/xics.c~powerpc_xics_fix_badness arch/powerpc/platforms/pseries/xics.c
--- linux-2.6/arch/powerpc/platforms/pseries/xics.c~powerpc_xics_fix_badness	2010-07-14 13:47:13.000000000 -0500
+++ linux-2.6-bjking1/arch/powerpc/platforms/pseries/xics.c	2010-07-14 13:47:13.000000000 -0500
@@ -549,8 +549,6 @@ static irqreturn_t xics_ipi_dispatch(int
 	unsigned long *tgt = &per_cpu(xics_ipi_message, cpu);
-	WARN_ON(cpu_is_offline(cpu));
 	mb();	/* order mmio clearing qirr */
 	while (*tgt) {
 		if (test_and_clear_bit(PPC_MSG_CALL_FUNCTION, tgt)) {

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