Messages in this thread | | | Date | Mon, 16 May 2011 20:53:09 +0100 | Subject | Re: [patch 1/4] x86, ioapic: fix potential resume deadlock | From | Daniel J Blueman <> |
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On 16 May 2011 19:56, Suresh Siddha <suresh.b.siddha@intel.com> wrote: > From: Daniel J Blueman <daniel.blueman@gmail.com> > 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 > buffers. > > Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> > Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> > Cc: stable@kernel.org [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, > - GFP_KERNEL); > + GFP_ATOMIC); > 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; > }
I just tested this patch series (1-3) and it does addresses the resume allocation failures I was consistently seeing (triggering your warning); it passes nicely with full lock, allocation etc debugging, so looks all good. Tested-by: Daniel J Blueman <daniel.blueman@gmail.com>
Thanks, Suresh!
Daniel -- Daniel J Blueman -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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