* [PATCH] mm/thp: fix vmas tear down race with thp splitting
@ 2013-12-24 1:54 Wanpeng Li
2013-12-24 15:21 ` Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Wanpeng Li @ 2013-12-24 1:54 UTC (permalink / raw)
To: Andrew Morton
Cc: Kirill A. Shutemov, Sasha Levin, Dave Jones, linux-mm,
linux-kernel, Wanpeng Li
Sasha reports unmap_page_range tears down pmd range which is race with thp
splitting during page reclaim. Transparent huge page will be splitting
during page reclaim. However, split pmd lock which held by __split_trans_huge_lock
can't prevent __split_huge_page_refcount running in parallel. This patch fix
it by hold compound lock to check if __split_huge_page_refcount is running
underneath, in that case zap huge pmd range should be fallback.
[ 265.474585] kernel BUG at mm/huge_memory.c:1440!
[ 265.475129] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 265.476684] Dumping ftrace buffer:
[ 265.477144] (ftrace buffer empty)
[ 265.478398] Modules linked in:
[ 265.478807] CPU: 8 PID: 11344 Comm: trinity-c206 Tainted: G W 3.13.0-rc5-next-20131223-sasha-00015-gec22156-dirty #8
[ 265.480172] task: ffff8801cb573000 ti: ffff8801cbd3a000 task.ti: ffff8801cbd3a000
[ 265.480172] RIP: 0010:[<ffffffff812c7f70>] [<ffffffff812c7f70>] zap_huge_pmd+0x170/0x1f0
[ 265.480172] RSP: 0000:ffff8801cbd3bc78 EFLAGS: 00010246
[ 265.480172] RAX: 015fffff80090018 RBX: ffff8801cbd3bde8 RCX: ffffffffffffff9c
[ 265.480172] RDX: ffffffffffffffff RSI: 0000000000000008 RDI: ffff8800bffd2000
[ 265.480172] RBP: ffff8801cbd3bcb8 R08: 0000000000000000 R09: 0000000000000000
[ 265.480172] R10: 0000000000000001 R11: 0000000000000000 R12: ffffea0002856740
[ 265.480172] R13: ffffea0002d50000 R14: 00007ff915000000 R15: 00007ff930e48fff
[ 265.480172] FS: 00007ff934899700(0000) GS:ffff88014d400000(0000) knlGS:0000000000000000
[ 265.480172] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 265.480172] CR2: 00007ff93428a000 CR3: 000000010babe000 CR4: 00000000000006e0
[ 265.480172] Stack:
[ 265.480172] 00000000000004dd ffff8801ccbfbb60 ffff8801cbd3bcb8 ffff8801cbb15540
[ 265.480172] 00007ff915000000 00007ff930e49000 ffff8801cbd3bde8 00007ff930e48fff
[ 265.480172] ffff8801cbd3bd48 ffffffff812885b6 ffff88005f5d20c0 00007ff915200000
[ 265.480172] Call Trace:
[ 265.480172] [<ffffffff812885b6>] unmap_page_range+0x2c6/0x410
[ 265.480172] [<ffffffff81288801>] unmap_single_vma+0x101/0x120
[ 265.480172] [<ffffffff81288881>] unmap_vmas+0x61/0xa0
[ 265.480172] [<ffffffff8128f730>] exit_mmap+0xd0/0x170
[ 265.480172] [<ffffffff81138860>] mmput+0x70/0xe0
[ 265.480172] [<ffffffff8113c89d>] exit_mm+0x18d/0x1a0
[ 265.480172] [<ffffffff811ea355>] ? acct_collect+0x175/0x1b0
[ 265.480172] [<ffffffff8113ed0f>] do_exit+0x26f/0x520
[ 265.480172] [<ffffffff8113f069>] do_group_exit+0xa9/0xe0
[ 265.480172] [<ffffffff8113f0b7>] SyS_exit_group+0x17/0x20
[ 265.480172] [<ffffffff845f10d0>] tracesys+0xdd/0xe2
[ 265.480172] Code: 0f 0b 66 0f 1f 84 00 00 00 00 00 eb fe 66 0f 1f
44 00 00 48 8b 03 f0 48 81 80 50 03 00 00 00 fe ff ff 49 8b 45 00 f6
c4 40 75 10 <0f> 0b 66 0f 1f 44 00 00 eb fe 66 0f 1f 44 00 00 48 8b 03
f0 48
[ 265.480172] RIP [<ffffffff812c7f70>] zap_huge_pmd+0x170/0x1f0
[ 265.480172] RSP <ffff8801cbd3bc78>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
mm/huge_memory.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7de1bf8..d1e0c80 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1414,6 +1414,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
{
spinlock_t *ptl;
int ret = 0;
+ unsigned long flags;
if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
struct page *page;
@@ -1426,6 +1427,15 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
* operations.
*/
orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);
+ page = pmd_page(orig_pmd);
+ flags = compound_lock_irqsave(page);
+ if (unlikely(!PageHead(page))) {
+ /*
+ * __split_huge_page_refcount run before us
+ */
+ compound_unlock_irqrestore(page, flags);
+ return ret;
+ }
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
if (is_huge_zero_pmd(orig_pmd)) {
@@ -1433,7 +1443,6 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
spin_unlock(ptl);
put_huge_zero_page();
} else {
- page = pmd_page(orig_pmd);
page_remove_rmap(page);
VM_BUG_ON(page_mapcount(page) < 0);
add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
@@ -1442,6 +1451,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
spin_unlock(ptl);
tlb_remove_page(tlb, page);
}
+ compound_unlock_irqrestore(page, flags);
+
pte_free(tlb->mm, pgtable);
ret = 1;
}
--
1.8.3.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] mm/thp: fix vmas tear down race with thp splitting
2013-12-24 1:54 [PATCH] mm/thp: fix vmas tear down race with thp splitting Wanpeng Li
@ 2013-12-24 15:21 ` Sasha Levin
0 siblings, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2013-12-24 15:21 UTC (permalink / raw)
To: Wanpeng Li, Andrew Morton
Cc: Kirill A. Shutemov, Dave Jones, linux-mm, linux-kernel
On 12/23/2013 08:54 PM, Wanpeng Li wrote:
> Sasha reports unmap_page_range tears down pmd range which is race with thp
> splitting during page reclaim. Transparent huge page will be splitting
> during page reclaim. However, split pmd lock which held by __split_trans_huge_lock
> can't prevent __split_huge_page_refcount running in parallel. This patch fix
> it by hold compound lock to check if __split_huge_page_refcount is running
> underneath, in that case zap huge pmd range should be fallback.
>
> [ 265.474585] kernel BUG at mm/huge_memory.c:1440!
> [ 265.475129] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> [ 265.476684] Dumping ftrace buffer:
> [ 265.477144] (ftrace buffer empty)
> [ 265.478398] Modules linked in:
> [ 265.478807] CPU: 8 PID: 11344 Comm: trinity-c206 Tainted: G W 3.13.0-rc5-next-20131223-sasha-00015-gec22156-dirty #8
> [ 265.480172] task: ffff8801cb573000 ti: ffff8801cbd3a000 task.ti: ffff8801cbd3a000
> [ 265.480172] RIP: 0010:[<ffffffff812c7f70>] [<ffffffff812c7f70>] zap_huge_pmd+0x170/0x1f0
> [ 265.480172] RSP: 0000:ffff8801cbd3bc78 EFLAGS: 00010246
> [ 265.480172] RAX: 015fffff80090018 RBX: ffff8801cbd3bde8 RCX: ffffffffffffff9c
> [ 265.480172] RDX: ffffffffffffffff RSI: 0000000000000008 RDI: ffff8800bffd2000
> [ 265.480172] RBP: ffff8801cbd3bcb8 R08: 0000000000000000 R09: 0000000000000000
> [ 265.480172] R10: 0000000000000001 R11: 0000000000000000 R12: ffffea0002856740
> [ 265.480172] R13: ffffea0002d50000 R14: 00007ff915000000 R15: 00007ff930e48fff
> [ 265.480172] FS: 00007ff934899700(0000) GS:ffff88014d400000(0000) knlGS:0000000000000000
> [ 265.480172] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [ 265.480172] CR2: 00007ff93428a000 CR3: 000000010babe000 CR4: 00000000000006e0
> [ 265.480172] Stack:
> [ 265.480172] 00000000000004dd ffff8801ccbfbb60 ffff8801cbd3bcb8 ffff8801cbb15540
> [ 265.480172] 00007ff915000000 00007ff930e49000 ffff8801cbd3bde8 00007ff930e48fff
> [ 265.480172] ffff8801cbd3bd48 ffffffff812885b6 ffff88005f5d20c0 00007ff915200000
> [ 265.480172] Call Trace:
> [ 265.480172] [<ffffffff812885b6>] unmap_page_range+0x2c6/0x410
> [ 265.480172] [<ffffffff81288801>] unmap_single_vma+0x101/0x120
> [ 265.480172] [<ffffffff81288881>] unmap_vmas+0x61/0xa0
> [ 265.480172] [<ffffffff8128f730>] exit_mmap+0xd0/0x170
> [ 265.480172] [<ffffffff81138860>] mmput+0x70/0xe0
> [ 265.480172] [<ffffffff8113c89d>] exit_mm+0x18d/0x1a0
> [ 265.480172] [<ffffffff811ea355>] ? acct_collect+0x175/0x1b0
> [ 265.480172] [<ffffffff8113ed0f>] do_exit+0x26f/0x520
> [ 265.480172] [<ffffffff8113f069>] do_group_exit+0xa9/0xe0
> [ 265.480172] [<ffffffff8113f0b7>] SyS_exit_group+0x17/0x20
> [ 265.480172] [<ffffffff845f10d0>] tracesys+0xdd/0xe2
> [ 265.480172] Code: 0f 0b 66 0f 1f 84 00 00 00 00 00 eb fe 66 0f 1f
> 44 00 00 48 8b 03 f0 48 81 80 50 03 00 00 00 fe ff ff 49 8b 45 00 f6
> c4 40 75 10 <0f> 0b 66 0f 1f 44 00 00 eb fe 66 0f 1f 44 00 00 48 8b 03
> f0 48
> [ 265.480172] RIP [<ffffffff812c7f70>] zap_huge_pmd+0x170/0x1f0
> [ 265.480172] RSP <ffff8801cbd3bc78>
>
> Reported-by: Sasha Levin <sasha.levin@oracle.com>
> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
> ---
Ran a round of testing overnight. While the BUG seems to be gone I'm now getting:
[ 879.815434] BUG: Bad page state in process trinity-c115 pfn:29a00
[ 879.816430] page:ffffea0000a68000 count:0 mapcount:0 mapping: (null) index:
0x7f2f20000
[ 879.817654] page flags: 0x5fffff81084008(uptodate|head|swapbacked|compound_lock)
[ 879.818848] Modules linked in:
[ 879.819340] CPU: 1 PID: 18824 Comm: trinity-c115 Tainted: G W 3.13.0-rc5-n
ext-20131223-sasha-00016-g3010ae9-dirty #13
[ 879.821142] ffffea0000a68000 ffff880188345a58 ffffffff845e014c 0000000000000009
[ 879.822492] ffffea0000a68000 ffff880188345a78 ffffffff8125c301 ffff880188345a78
[ 879.823858] 0000000000000200 ffff880188345ac8 ffffffff8125cd83 ffff880100000000
[ 879.825128] Call Trace:
[ 879.825568] [<ffffffff845e014c>] dump_stack+0x52/0x7f
[ 879.826425] [<ffffffff8125c301>] bad_page+0xf1/0x120
[ 879.827296] [<ffffffff8125cd83>] free_pages_prepare+0x133/0x1f0
[ 879.828276] [<ffffffff8125f254>] __free_pages_ok+0x24/0x150
[ 879.829267] [<ffffffff8125f39b>] free_compound_page+0x1b/0x20
[ 879.830547] [<ffffffff81267ebc>] __put_compound_page+0x1c/0x30
[ 879.831360] [<ffffffff81267f60>] put_compound_page+0x60/0x2e0
[ 879.832284] [<ffffffff8126824b>] release_pages+0x6b/0x230
[ 879.833230] [<ffffffff8129ef46>] free_pages_and_swap_cache+0xa6/0xd0
[ 879.834297] [<ffffffff81285dff>] tlb_flush_mmu+0x6f/0x90
[ 879.835146] [<ffffffff812c8078>] zap_huge_pmd+0x308/0x410
[ 879.836097] [<ffffffff81288526>] unmap_page_range+0x2c6/0x410
[ 879.837034] [<ffffffff81288771>] unmap_single_vma+0x101/0x120
[ 879.838027] [<ffffffff812887f1>] unmap_vmas+0x61/0xa0
[ 879.838892] [<ffffffff8128f6a0>] exit_mmap+0xd0/0x170
[ 879.839794] [<ffffffff81138860>] mmput+0x70/0xe0
[ 879.841079] [<ffffffff8113c89d>] exit_mm+0x18d/0x1a0
[ 879.841565] [<ffffffff811ea355>] ? acct_collect+0x175/0x1b0
[ 879.842411] [<ffffffff8113ed0f>] do_exit+0x26f/0x520
[ 879.843169] [<ffffffff8113f069>] do_group_exit+0xa9/0xe0
[ 879.844033] [<ffffffff8113f0b7>] SyS_exit_group+0x17/0x20
[ 879.844967] [<ffffffff845f1290>] tracesys+0xdd/0xe2
Thanks,
Sasha
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