linux/arch/powerpc
Nishanth Aravamudan 1cf389df09 powerpc/iommu: Use GFP_KERNEL instead of GFP_ATOMIC in iommu_init_table()
Under heavy (DLPAR?) stress, we tripped this panic() in
arch/powerpc/kernel/iommu.c::iommu_init_table():

	page = alloc_pages_node(nid, GFP_ATOMIC, get_order(sz));
	if (!page)
		panic("iommu_init_table: Can't allocate %ld bytes\n", sz);

Before the panic() we got a page allocation failure for an order-2
allocation. There appears to be memory free, but perhaps not in the
ATOMIC context. I looked through all the call-sites of
iommu_init_table() and didn't see any obvious reason to need an ATOMIC
allocation. Most call-sites in fact have an explicit GFP_KERNEL
allocation shortly before the call to iommu_init_table(), indicating we
are not in an atomic context. There is some indirection for some paths,
but I didn't see any locks indicating that GFP_KERNEL is inappropriate.

With this change under the same conditions, we have not been able to
reproduce the panic.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org>
2013-10-03 17:24:44 +10:00
..
boot powerpc/zImage: make the "OF" wrapper support ePAPR boot 2013-09-25 14:18:44 +10:00
configs powerpc/85xx: Add C293PCIE board support 2013-08-23 19:43:24 -05:00
crypto powerpc: Fix compile of sha1-powerpc-asm.S on 32-bit 2013-03-05 16:56:26 +11:00
include powerpc: Remove ksp_limit on ppc64 2013-09-25 14:15:51 +10:00
kernel powerpc/iommu: Use GFP_KERNEL instead of GFP_ATOMIC in iommu_init_table() 2013-10-03 17:24:44 +10:00
kvm Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-09-06 10:49:42 -07:00
lib powerpc: Restore registers on error exit from csum_partial_copy_generic() 2013-10-03 17:22:42 +10:00
math-emu powerpc/math-emu: Fix load/store indexed emulation 2013-08-14 14:59:57 +10:00
mm powerpc: Fix memory hotplug with sparse vmemmap 2013-10-03 17:21:38 +10:00
net ppc: bpf_jit: can call module_free() from any context 2013-05-20 14:03:50 -07:00
oprofile Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-09-06 10:49:42 -07:00
perf Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-09-06 10:49:42 -07:00
platforms powerpc/pseries: Do not start secondaries in Open Firmware 2013-09-25 14:19:00 +10:00
sysdev IOMMU Updates for Linux v3.12 2013-09-12 11:29:26 -07:00
xmon powerpc/xmon: Fix printing of set of CPUs in xmon 2013-09-05 17:29:19 +10:00
Kconfig Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
Kconfig.debug Merge branch 'kconfig-diet' from Dave Hansen 2013-07-04 11:25:51 -07:00
Makefile powerpc/e500: Set -mcpu flag for 32-bit e500 2013-08-20 20:49:56 -05:00
relocs_check.pl Fix warning typo "CONFIG_RELCOATABLE" 2013-05-29 15:11:30 +02:00