Xen project Mailing List

On Fri, Oct 23, 2009 at 5:05 PM, Boris Derzhavets <bderzhavets@xxxxxxxxx> wrote:

Dmesg log attached

=============================================
[ INFO: possible recursive locking detected ]
2.6.31.4 #1
---------------------------------------------
init/1 is trying to acquire lock:
(__pte_lockptr(page)){+.+...}, at: [<ffffffff81025090>] _pin_lock+0xb0/0x124

but task is already holding lock:
(__pte_lockptr(page)){+.+...}, at: [<ffffffff81025090>] _pin_lock+0xb0/0x124

other info that might help us debug this:
4 locks held by init/1:
#0: (&mm->mmap_sem){++++++}, at: [<ffffffff8104193f>] dup_mm+0xc7/0x3a2
#1: (&mm->mmap_sem/1){+.+.+.}, at: [<ffffffff81041954>] dup_mm+0xdc/0x3a2
#2: (&mm->page_table_lock){+.+...}, at: [<ffffffff8102501b>] _pin_lock+0x3b/0x124
#3: (__pte_lockptr(page)){+.+...}, at: [<ffffffff81025090>] _pin_lock+0xb0/0x124

stack backtrace:
Pid: 1, comm: init Not tainted 2.6.31.4 #1
Call Trace:
[<ffffffff81072a6d>] __lock_acquire+0xb70/0xbfa
[<ffffffff81072beb>] lock_acquire+0xf4/0x152
[<ffffffff81025090>] ? _pin_lock+0xb0/0x124
[<ffffffff81025090>] ? _pin_lock+0xb0/0x124
[<ffffffff814bc8bb>] _spin_lock+0x45/0x8e
[<ffffffff81025090>] ? _pin_lock+0xb0/0x124
[<ffffffff81025090>] _pin_lock+0xb0/0x124
[<ffffffff81025928>] mm_pin+0x33/0x61
[<ffffffff810259a3>] arch_dup_mmap+0x4d/0x6a
[<ffffffff81041b5d>] dup_mm+0x2e5/0x3a2
[<ffffffff81042823>] copy_process+0xba2/0x13c5
[<ffffffff810431b9>] do_fork+0x173/0x335
[<ffffffff8110b3a9>] ? do_vfs_ioctl+0x4aa/0x506
[<ffffffff8100a353>] ? sysret_check+0x41/0xc0
[<ffffffff81008358>] sys_clone+0x3b/0x51
[<ffffffff814bbebb>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff8100a7b3>] stub_clone+0x13/0x20
[<ffffffff8100a308>] ? system_call_fastpath+0x16/0x1b

Boris

--- On Fri, 10/23/09, Andrew Lyon <andrew.lyon@xxxxxxxxx> wrote:

From: Andrew Lyon <andrew.lyon@xxxxxxxxx>
Subject: Re: [Xen-users] rebased opensuse 2.6.31 xen patches
To: "Marco Nenciarini" <mnencia@xxxxxxxxxxxxxx>, "Jan Beulich" <jbeulich@xxxxxxxxxx>, "xen-users List" <xen-users@xxxxxxxxxxxxxxxxxxx>
Date: Friday, October 23, 2009, 7:28 AM

On Fri, Oct 23, 2009 at 12:03 PM, Marco Nenciarini
<mnencia@xxxxxxxxxxxxxx> wrote:
> Andrew Lyon ha scritto:
>>
>> On Fri, Oct 23, 2009 at 11:27 AM, Marco Nenciarini
>>
>> Thanks, does this fix a problem you have encountered? If so I would
>> like to see an example of the oops or warning you receive due to this
>> error.
>>
>> Andy
>
> Without that patch it does not compile at all.
>
>
> scripts/kconfig/conf -s arch/x86/Kconfig
> Using
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen
> as source for kernel
> GEN
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/build_amd64_xen_amd64/Makefile
> CHK include/linux/version.h
> UPD include/linux/version.h
> CHK include/linux/utsrelease.h
> UPD include/linux/utsrelease.h
> SYMLINK include/asm -> include/asm-x86
> Updating
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/build_amd64_xen_amd64/scripts/Makefile.xen
> CC kernel/bounds.s
> GEN include/linux/bounds.h
> CC arch/x86/kernel/asm-offsets.s
> In file included from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/include/linux/spinlock.h:88,
> from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/include/linux/seqlock.h:29,
> from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/include/linux/time.h:8,
> from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/include/linux/stat.h:60,
> from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/include/linux/module.h:10,
> from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/include/linux/crypto.h:21,
> from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/kernel/asm-offsets_64.c:7,
> from
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/kernel/asm-offsets.c:4:
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:134:
> error: expected identifier or â(â before â:â token
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:138:
> error: expected identifier or â(â before â}â token
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:138:
> error: expected identifier or â(â before âwhileâ
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:
> In function â__ticket_spin_lockâ:
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:217:
> error: expected â:â or â)â before â;â token
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:217:
> warning: unused variable âtmpâ
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:227:
> error: expected âwhileâ before âstaticâ
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/kernel/asm-offsets.c:5:
> error: expected declaration or statement at end of input
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:215:
> warning: unused variable âfreeâ
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:214:
> warning: unused variable âcountâ
> /home/mnencia/deb/kernel/lab/linux-2.6-2.6.31/debian/build/source_amd64_xen/arch/x86/include/mach-xen/asm/spinlock.h:214:
> warning: unused variable âtokenâ
> make[5]: *** [arch/x86/kernel/asm-offsets.s] Error 1
> make[4]: *** [prepare0] Error 2
>
> Marco
>
> --
> ---------------------------------------------------------------------
> | Marco Nenciarini | Debian/GNU Linux Developer - Plug Member |
> | mnencia@xxxxxxxxxxxxxx | http://www.prato.linux.it/~mnencia |
> ---------------------------------------------------------------------
> Key fingerprint = FED9 69C7 9E67 21F5 7D95 5270 6864 730D F095 E5E4
>
>

Weird, I can compile both 32 and 64 bit domU and dom0 without any
errors like that, looking at the code I'd expect to hit that error
straight away.

I've CC'ed Jan and attached your patch to this message, he may want to
merge this upstream (or point out that I'm wrong again).

Andy

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Can you test with CONFIG_NR_CPUS set to less than 256?

The code in spinlock.h is assembly and I'm not very familiar with that, before I spend a lot of time looking into this I'd like to know if the bug is specific to the codepath for > 256 cpus.

Thanks
Andy

Andy