Messages in this thread Patch in this message | | | From | "Aneesh Kumar K.V" <> | Subject | [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page | Date | Mon, 28 May 2012 20:51:30 +0530 |
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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
The change was introduced by "hugetlb: simplify migrate_huge_page() "
We should use compound page head instead of tail pages in migrate_huge_page().
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> --- mm/memory-failure.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
This is an important bug fix. If we want we can fold it with the not yet merged upstream patch mentioned above in linux-next. The stack trace for the crash is
[ 75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350 [ 75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0 [ 75.338386] Oops: 0002 [#1] SMP [ 75.338386] CPU 1 [ 75.338386] Modules linked in: ... ...
[ 75.338386] Call Trace: [ 75.338386] [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c [ 75.338386] [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c [ 75.338386] [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421 [ 75.338386] [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31 [ 75.338386] [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55 [ 75.338386] [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c [ 75.338386] [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55 [ 75.338386] [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc [ 75.338386] [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27 [ 75.338386] [<ffffffff81100839>] try_to_unmap+0x25/0x3c [ 75.338386] [<ffffffff810641c2>] ? console_unlock+0x210/0x238 [ 75.338386] [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4a45098..53a1495 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags) } /* Keep page count to indicate a given hugepage is isolated. */ - ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true); - put_page(page); + ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true); + put_page(hpage); if (ret) { pr_info("soft offline: %#lx: migration failed %d, type %lx\n", pfn, ret, page->flags); -- 1.7.10
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