Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH] [6/16] HWPOISON: Add basic support for poisoned pages in fault handler v2 | Date | Wed, 27 May 2009 22:12:32 +0200 (CEST) |
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- Add a new VM_FAULT_HWPOISON error code to handle_mm_fault. Right now architectures have to explicitely enable poison page support, so this is forward compatible to all architectures. They only need to add it when they enable poison page support. - Add poison page handling in swap in fault code
v2: Add missing delayacct_clear_flag (Hidehiro Kawai)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
--- include/linux/mm.h | 3 ++- mm/memory.c | 18 +++++++++++++++--- 2 files changed, 17 insertions(+), 4 deletions(-)
Index: linux/mm/memory.c =================================================================== --- linux.orig/mm/memory.c 2009-05-27 21:13:54.000000000 +0200 +++ linux/mm/memory.c 2009-05-27 21:19:19.000000000 +0200 @@ -1315,7 +1315,8 @@ if (ret & VM_FAULT_ERROR) { if (ret & VM_FAULT_OOM) return i ? i : -ENOMEM; - else if (ret & VM_FAULT_SIGBUS) + if (ret & + (VM_FAULT_HWPOISON|VM_FAULT_SIGBUS)) return i ? i : -EFAULT; BUG(); } @@ -2459,8 +2460,15 @@ goto out; entry = pte_to_swp_entry(orig_pte); - if (is_migration_entry(entry)) { - migration_entry_wait(mm, pmd, address); + if (unlikely(non_swap_entry(entry))) { + if (is_migration_entry(entry)) { + migration_entry_wait(mm, pmd, address); + } else if (is_hwpoison_entry(entry)) { + ret = VM_FAULT_HWPOISON; + } else { + print_bad_pte(vma, address, pte, NULL); + ret = VM_FAULT_OOM; + } goto out; } delayacct_set_flag(DELAYACCT_PF_SWAPIN); @@ -2484,6 +2492,10 @@ /* Had to read the page from swap area: Major fault */ ret = VM_FAULT_MAJOR; count_vm_event(PGMAJFAULT); + } else if (PageHWPoison(page)) { + ret = VM_FAULT_HWPOISON; + delayacct_set_flag(DELAYACCT_PF_SWAPIN); + goto out; } lock_page(page); Index: linux/include/linux/mm.h =================================================================== --- linux.orig/include/linux/mm.h 2009-05-27 21:13:54.000000000 +0200 +++ linux/include/linux/mm.h 2009-05-27 21:19:18.000000000 +0200 @@ -702,11 +702,12 @@ #define VM_FAULT_SIGBUS 0x0002 #define VM_FAULT_MAJOR 0x0004 #define VM_FAULT_WRITE 0x0008 /* Special case for get_user_pages */ +#define VM_FAULT_HWPOISON 0x0010 /* Hit poisoned page */ #define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not return page */ #define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */ -#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS) +#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON) /* * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
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