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author | Nishanth Aravamudan <nacc@linux.vnet.ibm.com> | 2013-10-01 14:04:53 -0700 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-10-03 17:24:44 +1000 |
commit | 1cf389df090194a0976dc867b7fffe99d9d490cb (patch) | |
tree | 93e49d6e383d3ababfd7733aad9543566f0a681c /arch/powerpc/kernel/iommu.c | |
parent | d1211af3049f4c9c1d8d4eb8f8098cc4f4f0d0c7 (diff) | |
download | linux-1cf389df090194a0976dc867b7fffe99d9d490cb.tar.bz2 |
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>
Diffstat (limited to 'arch/powerpc/kernel/iommu.c')
-rw-r--r-- | arch/powerpc/kernel/iommu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 0adab06ce5c0..572bb5b95f35 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -661,7 +661,7 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid) /* number of bytes needed for the bitmap */ sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); - page = alloc_pages_node(nid, GFP_ATOMIC, get_order(sz)); + page = alloc_pages_node(nid, GFP_KERNEL, get_order(sz)); if (!page) panic("iommu_init_table: Can't allocate %ld bytes\n", sz); tbl->it_map = page_address(page); |