[patch 1/4] x86, ioapic: fix potential resume deadlock

From: Suresh Siddha
Date: Mon May 16 2011 - 14:59:35 EST

From: Daniel J Blueman <daniel.blueman@xxxxxxxxx>
Subject: x86, ioapic: fix potential resume deadlock

Fix a potential deadlock when resuming; here the calling function
has disabled interrupts, so we cannot sleep.

Change the memory allocation flag from GFP_KERNEL to GFP_ATOMIC.

TODO: We can do away with this memory allocation during resume by
reusing the ioapic suspend/resume code that uses boot time allocated

Signed-off-by: Daniel J Blueman <daniel.blueman@xxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: stable@xxxxxxxxxx [v2.6.39]
arch/x86/kernel/apic/io_apic.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
--- linux-2.6-tip.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
@@ -621,14 +621,14 @@ struct IO_APIC_route_entry **alloc_ioapi
struct IO_APIC_route_entry **ioapic_entries;

ioapic_entries = kzalloc(sizeof(*ioapic_entries) * nr_ioapics,
if (!ioapic_entries)
return 0;

for (apic = 0; apic < nr_ioapics; apic++) {
ioapic_entries[apic] =
kzalloc(sizeof(struct IO_APIC_route_entry) *
- nr_ioapic_registers[apic], GFP_KERNEL);
+ nr_ioapic_registers[apic], GFP_ATOMIC);
if (!ioapic_entries[apic])
goto nomem;

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