Patchwork [RFC,2/2] pseries/xics: use cpu_possible_mask rather than cpu_all_mask

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Submitter Nishanth Aravamudan
Date Sept. 27, 2010, 11:17 p.m.
Message ID <1285629463-27699-3-git-send-email-nacc@us.ibm.com>
Download mbox | patch
Permalink /patch/65928/
State Accepted
Commit f56029b5eafda6175be4e5c91ca69c04ccda3661
Headers show

Comments

Nishanth Aravamudan - Sept. 27, 2010, 11:17 p.m.
Current firmware only allows us to send IRQs to the first processor or
all processors. We currently check to see if the passed in mask is equal
to the all_mask, but the firmware is only considering whether the
request is for the equivalent of the possible_mask. Thus, we think the
request is for some subset of CPUs and only assign IRQs to the first CPU
(on systems without irqbalance running) as evidenced by
/proc/interrupts. By using possible_mask instead, we account for this
and proper interleaving of interrupts occurs. Without this change and
"pseries/xics: use cpu_possible_mask rather than cpu_all_mask", IRQs are
all routed to CPU0 on power machines not running irqbalance.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
---
 arch/powerpc/platforms/pseries/xics.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Patch

diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index 93834b0..7c1e342 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -178,7 +178,7 @@  static int get_irq_server(unsigned int virq, const struct cpumask *cpumask,
 	if (!distribute_irqs)
 		return default_server;
 
-	if (!cpumask_equal(cpumask, cpu_all_mask)) {
+	if (!cpumask_subset(cpu_possible_mask, cpumask)) {
 		int server = cpumask_first_and(cpu_online_mask, cpumask);
 
 		if (server < nr_cpu_ids)