Re: 2.6.17-rc1-mm3 dies in LTP on amd64

Andi Kleen
2006-04-18T17:11:19Z

On Tuesday 18 April 2006 18:59, Martin Bligh wrote:
> Runs most tests just fine, but not LTP.
> -mm2 ran LTP fine.

I don't think it's my patchkit - currently only has harmless things.

> Full log here:
> http://test.kernel.org/abat/28728/debug/console.log
>
> The trainwreck starts with:
>
> Modules linked in:
> Pid: 228, comm: kswapd0 Not tainted 2.6.17-rc1-mm3-autokern1 #1
> RIP: 0010:[<ffffffff8047a8dc>] <ffffffff8047a8dc>{__sched_text_start+1852}
> RSP: 0000:0000000000000000 EFLAGS: 00010046
> RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff805d9338
> RDX: ffff8100010c5090 RSI: ffffffff805d9338 RDI: ffff8100010c5090
> RBP: ffffffff805d9338 R08: 0000000000000010 R09: ffff8100e3e63d28
> R10: ffff8100e3e63a88 R11: 000000000000000b R12: ffff810000011280
> R13: ffff81007e186f40 R14: ffff810008003620 R15: 000002b9f81aa1c4
> FS: 0000000000000000(0000) GS:ffffffff805fa000(0000) knlGS:00000000f7ea7460
> CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
> CR2: fffffffffffffff8 CR3: 000000007174a000 CR4: 00000000000006e0
> Process kswapd0 (pid: 228, threadinfo ffff8100e3e62000, task
> ffff8100010c5090)
> Stack: ffffffff80578e20 ffff8100010c5090 0000000000000001 ffffffff80578f58
> 0000000000000000 ffffffff80578e78 ffffffff8020b082 ffffffff80578f58
> 0000000000000000 ffffffff80483520
> Call Trace: <#DF> <ffffffff8020b082>{show_registers+140}
> <ffffffff8020b30b>{__die+159} <ffffffff8020b380>{die+50}
> <ffffffff8020bb46>{do_double_fault+115}
> <ffffffff8020aa61>{double_fault+125}
> <ffffffff8047a8dc>{__sched_text_start+1852} <EOE>

Not very useful. Something double faulted, but it's not on the stack
[I wonder if the stack walker over double faults is broken. Jan - did you
ever test that after you redid the walker?]

If you can reproduce it on a Intel machine it might be possible to find
it using the last branch registers (patch for that available on request).

Otherwise binary search I guess.

-Andi