From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [BUG] Linux 2.6.25-rc2 - Kernel Ooops while running dbench
Date: Mon, 18 Feb 2008 04:59:54 -0800
Message-ID: <20080218045954.50503fb1.akpm@linux-foundation.org>
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Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-ext4@vger.kernel.org, Andy Whitcroft <apw@shadowen.org>,
	Balbir Singh <balbir@linux.vnet.ibm.com>,
	Christoph Lameter <clameter@sgi.com>, linux-mm@kvack.org
To: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
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On Sat, 16 Feb 2008 11:14:46 +0530 Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> wrote:

> The 2.6.25-rc2 kernel oopses while running dbench on ext3 filesystem
> mounted with mount -o data=writeback,nobh option on the x86_64 box
> 
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
> IP: [<ffffffff80274972>] kmem_cache_alloc+0x3a/0x6c
> PGD 1f6860067 PUD 1f5d64067 PMD 0 
> Oops: 0000 [1] SMP 
> CPU 3 
> Modules linked in:
> Pid: 4271, comm: dbench Not tainted 2.6.25-rc2-autotest #1
> RIP: 0010:[<ffffffff80274972>]  [<ffffffff80274972>] kmem_cache_alloc+0x3a/0x6c
> RSP: 0000:ffff8101fb041dc8  EFLAGS: 00010246
> RAX: 0000000000000000 RBX: ffff810180033c00 RCX: ffffffff8027b269
> RDX: 0000000000000000 RSI: 00000000000080d0 RDI: ffffffff80632d70
> RBP: 00000000000080d0 R08: 0000000000000001 R09: 0000000000000000
> R10: ffff8101feb36e50 R11: 0000000000000190 R12: 0000000000000001
> R13: 0000000000000000 R14: ffff8101f8f38000 R15: 00000000ffffff9c
> FS:  0000000000000000(0000) GS:ffff8101fff0f000(0063) knlGS:00000000f7e41460
> CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 00000001f5620000 CR4: 00000000000006e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process dbench (pid: 4271, threadinfo ffff8101fb040000, task ffff8101fb180000)
> Stack:  0000000000000001 ffff8101fb041ea8 0000000000000001 ffffffff8027b269
>  ffff8101fb041ea8 ffffffff80281fe8 0000000000000001 0000000000000000
>  ffff8101fb041ea8 00000000ffffff9c 000000000000000b 0000000000000001
> Call Trace:
>  [<ffffffff8027b269>] get_empty_filp+0x55/0xf9
>  [<ffffffff80281fe8>] __path_lookup_intent_open+0x22/0x8f
>  [<ffffffff80282853>] open_namei+0x86/0x5a7
>  [<ffffffff8027d019>] vfs_stat_fd+0x3c/0x4a
>  [<ffffffff80279ab1>] do_filp_open+0x1c/0x3d
>  [<ffffffff80279c2c>] get_unused_fd_flags+0x79/0x111
>  [<ffffffff80279dce>] do_sys_open+0x46/0xca
>  [<ffffffff80221c82>] ia32_sysret+0x0/0xa
> 

Looks to me like we broke slab.  Christoph is offline until the 27th..