On 03/11/2014 01:00 PM, Rik van Riel wrote:
On 03/11/2014 12:51 PM, Sasha Levin wrote:
On 03/11/2014 12:28 PM, Mel Gorman wrote:
On Fri, Mar 07, 2014 at 06:27:45PM +0000, Mel Gorman wrote:
This is a completely untested prototype. It rechecks pmd_trans_huge
under the lock and falls through if it hit a parallel split. It's not
perfect because it could decide to fall through just because there was
no prot_numa work to do but it's for illustration purposes. Secondly,
I noted that you are calling invalidate for every pmd range. Is that
not
a lot of invalidations? We could do the same by just tracking the
address
of the first invalidation.
And there were other minor issues. This is still untested but Sasha,
can you try it out please? I discussed this with Rik on IRC for a bit
and
reckon this should be sufficient if the correct race has been
identified.
Any luck with this patch Sasha? It passed basic tests here but I had not
seen the issue trigger either.
Sorry, I've been stuck in my weekend project of getting lockdep to work
with page locks :)
It takes a moment to test, so just to be sure - I should have only this
last patch applied?
Without the one in the original mail?
Indeed, only this patch should do it.
Okay. So just this patch on top of the latest -next shows the following issues:
1. BUG in task_numa_work:
[ 439.417171] BUG: unable to handle kernel paging request at ffff880e17530c00
[ 439.418216] IP: [<ffffffff81299385>] vmacache_find+0x75/0xa0
[ 439.419073] PGD 8904067 PUD 1028fcb067 PMD 1028f10067 PTE 8000000e17530060
[ 439.420340] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 439.420340] Dumping ftrace buffer:
[ 439.420340] (ftrace buffer empty)
[ 439.420340] Modules linked in:
[ 439.420340] CPU: 12 PID: 9937 Comm: trinity-c212 Tainted: G W 3.14.0-rc5-next-20140307-sasha-00009-g3b24300-dirty #137
[ 439.420340] task: ffff880e1a45b000 ti: ffff880e1a490000 task.ti: ffff880e1a490000
[ 439.420340] RIP: 0010:[<ffffffff81299385>] [<ffffffff81299385>] vmacache_find+0x75/0xa0
[ 439.420340] RSP: 0018:ffff880e1a491e68 EFLAGS: 00010286
[ 439.420340] RAX: ffff880e17530c00 RBX: 0000000000000000 RCX: 0000000000000001
[ 439.420340] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff880e1a45b000
[ 439.420340] RBP: ffff880e1a491e68 R08: 0000000000000000 R09: 0000000000000000
[ 439.420340] R10: 0000000000000001 R11: 0000000000000000 R12: ffff880e1ab75000
[ 439.420340] R13: ffff880e1ab75000 R14: 0000000000010000 R15: 0000000000000000
[ 439.420340] FS: 00007f3458c05700(0000) GS:ffff880d2b800000(0000) knlGS:0000000000000000
[ 439.420340] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 439.420340] CR2: ffff880e17530c00 CR3: 0000000e1a472000 CR4: 00000000000006a0
[ 439.420340] Stack:
[ 439.420340] ffff880e1a491e98 ffffffff812a7610 ffffffff8118de40 0000000000000117
[ 439.420340] 00000001000036da ffff880e1a45b000 ffff880e1a491ef8 ffffffff8118de4b
[ 439.420340] ffff880e1a491ec8 ffffffff81269575 ffff880e1ab750a8 ffff880e1a45b000
[ 439.420340] Call Trace:
[ 439.420340] [<ffffffff812a7610>] find_vma+0x20/0x90
[ 439.420340] [<ffffffff8118de40>] ? task_numa_work+0x130/0x360
[ 439.420340] [<ffffffff8118de4b>] task_numa_work+0x13b/0x360
[ 439.420340] [<ffffffff81269575>] ? context_tracking_user_exit+0x195/0x1d0
[ 439.420340] [<ffffffff8116c5be>] task_work_run+0xae/0xf0
[ 439.420340] [<ffffffff8106ffbe>] do_notify_resume+0x8e/0xe0
[ 439.420340] [<ffffffff844b17a2>] int_signal+0x12/0x17
[ 439.420340] Code: 42 10 00 00 00 00 48 c7 42 18 00 00 00 00 eb 38 66 0f 1f 44 00 00 31 d2 48 89 c7 48 63 ca 48 8b 84 cf b8 07 00 00 48 85 c0 74 0b <48> 39 30 77 06 48 3b 70 08 72 12 ff c2 83 fa 04 75 de 66 0f 1f
[ 439.420340] RIP [<ffffffff81299385>] vmacache_find+0x75/0xa0
[ 439.420340] RSP <ffff880e1a491e68>
[ 439.420340] CR2: ffff880e17530c00
2. Similar to the above, but with a different trace:
[ 304.212158] BUG: unable to handle kernel paging request at ffff88020d37f800
[ 304.220420] IP: [<ffffffff81299385>] vmacache_find+0x75/0xa0
[ 304.220420] PGD 8904067 PUD 102effb067 PMD 102ef91067 PTE 800000020d37f060
[ 304.220420] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 304.220420] Dumping ftrace buffer:
[ 304.220420] (ftrace buffer empty)
[ 304.220420] Modules linked in:
[ 304.220420] CPU: 30 PID: 11157 Comm: trinity-c393 Tainted: G B W 3.14.0-rc5-next-20140307-sasha-00009-g3b24300-dirty #137
[ 304.220420] task: ffff881020a90000 ti: ffff88101fda2000 task.ti: ffff88101fda2000
[ 304.260466] RIP: 0010:[<ffffffff81299385>] [<ffffffff81299385>] vmacache_find+0x75/0xa0
[ 304.260466] RSP: 0000:ffff88101fda3da8 EFLAGS: 00010286
[ 304.260466] RAX: ffff88020d37f800 RBX: 00007f7f92f680fc RCX: 0000000000000000
[ 304.260466] RDX: 0000000000000000 RSI: 00007f7f92f680fc RDI: ffff881020a90000
[ 304.260466] RBP: ffff88101fda3da8 R08: 0000000000000001 R09: 0000000000000000
[ 304.260466] R10: 0000000000000000 R11: 0000000000000000 R12: ffff881021358000
[ 304.260466] R13: 0000000000000000 R14: ffff8810213580a8 R15: ffff881021358000
[ 304.260466] FS: 00007f7f92f8d700(0000) GS:ffff880f2ba00000(0000) knlGS:0000000000000000
[ 304.260466] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 304.260466] CR2: ffff88020d37f800 CR3: 000000101fd6b000 CR4: 00000000000006a0
[ 304.260466] Stack:
[ 304.260466] ffff88101fda3dd8 ffffffff812a7610 ffffffff844abd82 00007f7f92f680fc
[ 304.260466] 00007f7f92f680fc 00000000000000a8 ffff88101fda3ef8 ffffffff844abdd6
[ 304.260466] ffff88101fda3e08 ffffffff811a60d6 0000000000000000 ffff881020a90000
[ 304.260466] Call Trace:
[ 304.260466] [<ffffffff812a7610>] find_vma+0x20/0x90
[ 304.260466] [<ffffffff844abd82>] ? __do_page_fault+0x302/0x5d0
[ 304.260466] [<ffffffff844abdd6>] __do_page_fault+0x356/0x5d0
[ 304.260466] [<ffffffff811a60d6>] ? trace_hardirqs_off_caller+0x16/0x1a0
[ 304.260466] [<ffffffff8118ab46>] ? vtime_account_user+0x96/0xb0
[ 304.260466] [<ffffffff844ac4d2>] ? preempt_count_sub+0xe2/0x120
[ 304.260466] [<ffffffff81269567>] ? context_tracking_user_exit+0x187/0x1d0
[ 304.260466] [<ffffffff811a60d6>] ? trace_hardirqs_off_caller+0x16/0x1a0
[ 304.260466] [<ffffffff844ac115>] do_page_fault+0x45/0x70
[ 304.260466] [<ffffffff844ab3c6>] do_async_page_fault+0x36/0x100
[ 304.260466] [<ffffffff844a7f58>] async_page_fault+0x28/0x30
[ 304.260466] Code: 42 10 00 00 00 00 48 c7 42 18 00 00 00 00 eb 38 66 0f 1f 44 00 00 31 d2 48 89 c7 48 63 ca 48 8b 84 cf b8 07 00 00 48 85 c0 74 0b <48> 39 30 77 06 48 3b 70 08 72 12 ff c2 83 fa 04 75 de 66 0f 1f
[ 304.260466] RIP [<ffffffff81299385>] vmacache_find+0x75/0xa0
[ 304.260466] RSP <ffff88101fda3da8>
[ 304.260466] CR2: ffff88020d37f800
3. This one is a new issue. Might be related to something else but it seems related as I've never
saw it before this patch:
[ 560.473342] kernel BUG at mm/mmap.c:439!
[ 560.473766] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 560.474723] Dumping ftrace buffer:
[ 560.475410] (ftrace buffer empty)
[ 560.476098] Modules linked in:
[ 560.476241] CPU: 10 PID: 17037 Comm: trinity-c84 Tainted: G W 3.14.0-rc5-next-20140307-sasha-00009-g3b24300-dirty #137
[ 560.477651] task: ffff880424310000 ti: ffff8803eec4c000 task.ti: ffff8803eec4c000
[ 560.478595] RIP: 0010:[<ffffffff812a6ef5>] [<ffffffff812a6ef5>] validate_mm+0x115/0x140
[ 560.479749] RSP: 0018:ffff8803eec4de98 EFLAGS: 00010296
[ 560.480471] RAX: 0000000000000012 RBX: 00007fff8ae88000 RCX: 0000000000000006
[ 560.481490] RDX: 0000000000000006 RSI: ffff880424310cf0 RDI: 0000000000000282
[ 560.481490] RBP: ffff8803eec4dec8 R08: 0000000000000001 R09: 0000000000000001
[ 560.481490] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8803f61aa000
[ 560.481490] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000048
[ 560.481490] FS: 00007f799ddf6700(0000) GS:ffff880b2b800000(0000) knlGS:0000000000000000
[ 560.481490] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 560.481490] CR2: 0000000004502048 CR3: 00000003f8bcb000 CR4: 00000000000006a0
[ 560.481490] Stack:
[ 560.481490] ffff8803eec4dec8 0000000000000000 ffff8803f61aa000 ffff8800a22fae00
[ 560.481490] 0000000000000000 00007f799d4dc000 ffff8803eec4df28 ffffffff812a8fb7
[ 560.481490] ffffffff00000001 ffff880b21453600 ffff8800a22fae10 ffff8803f61aa008
[ 560.481490] Call Trace:
[ 560.481490] [<ffffffff812a8fb7>] do_munmap+0x307/0x360
[ 560.493775] [<ffffffff812a9056>] ? vm_munmap+0x46/0x80
[ 560.493775] [<ffffffff812a9064>] vm_munmap+0x54/0x80
[ 560.493775] [<ffffffff812a90bc>] SyS_munmap+0x2c/0x40
[ 560.493775] [<ffffffff844b1690>] tracesys+0xdd/0xe2
[ 560.493775] Code: 32 fd ff ff 41 8b 74 24 58 39 f0 74 19 89 c2 48 c7 c7 19 f5 6d 85 31 c0 e8 45 8c 1f 03 eb 0c 0f 1f 80 00 00 00 00 45 85 ed 74 0d <0f> 0b 66 0f 1f 84 00 00 00 00 00 eb fe 48 83 c4 08 5b 41 5c 41
[ 560.493775] RIP [<ffffffff812a6ef5>] validate_mm+0x115/0x140
[ 560.493775] RSP <ffff8803eec4de98>
Thanks,
Sasha
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