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Subject: Re: l2arc_feed_thread page fault on r287138
To: Bryan Drewery <bdrewery@FreeBSD.org>,
 "freebsd-fs@freebsd.org" <freebsd-fs@FreeBSD.org>
References: <55DCCDA3.8030605@FreeBSD.org>
Cc: Alexander Motin <mav@FreeBSD.org>
From: Andriy Gapon <avg@FreeBSD.org>
Message-ID: <55DCCE0D.8050902@FreeBSD.org>
Date: Tue, 25 Aug 2015 23:20:29 +0300
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On 25/08/2015 23:18, Bryan Drewery wrote:
>> Fatal trap 12: page fault while in kernel mode
>> cpuid = 2; apic id = 02
>> fault virtual address   = 0xc4
>> fault code              = supervisor read data, page not present
>> instruction pointer     = 0x20:0xffffffff80ce6c63
>> stack pointer           = 0x28:0xfffffe3553e689d0
>> frame pointer           = 0x28:0xfffffe3553e68a00
>> code segment            = base 0x0, limit 0xfffff, type 0x1b
>>                         = DPL 0, pres 1, long 1, def32 0, gran 1
>> processor eflags        = interrupt enabled, resume, IOPL = 0
>> current process         = 6 (l2arc_feed_thread)
>> [ thread pid 6 tid 100172 ]
>> Stopped at      uma_dbg_free+0x53:      movl    0xc4(%rdi),%esi
>> db> bt
>> Tracing pid 6 tid 100172 td 0xfffff8012551c9a0
>> uma_dbg_free() at uma_dbg_free+0x53/frame 0xfffffe3553e68a00
>> uma_zfree_arg() at uma_zfree_arg+0xaf/frame 0xfffffe3553e68a60
>> l2arc_feed_thread() at l2arc_feed_thread+0xe0b/frame 0xfffffe3553e68bb0
>> fork_exit() at fork_exit+0x84/frame 0xfffffe3553e68bf0
>> fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe3553e68bf0
>> --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
>> db>
> 

A little bit more debug info like line numbers, argument values, etc
would be nice.

-- 
Andriy Gapon