Date: Thu, 12 Jun 2014 22:56:47 +0200 From: Hans Petter Selasky <hps@selasky.org> To: Alan Cox <alc@rice.edu>, Ian Lepore <ian@FreeBSD.org> Cc: "arm@freebsd.org" <arm@FreeBSD.org> Subject: Re: RPI-B VM panic Message-ID: <539A140F.6020107@selasky.org> In-Reply-To: <5399FB57.8090102@rice.edu> References: <539170AA.2000109@selasky.org> <5396947A.1060601@selasky.org> <5396A0D1.80309@selasky.org> <5396AF63.6040209@selasky.org> <8BA66A45-E08A-475D-A1FA-5047E862681E@rice.edu> <5398B6EA.9030408@selasky.org> <A9433B36-C15C-455E-AB80-3999596936F9@rice.edu> <5398BFD9.60502@selasky.org> <7390A211-C949-4079-B3DA-BF23798B8992@rice.edu> <539942C0.5010706@selasky.org> <5399DF7F.4010501@rice.edu> <5399E349.5050600@selasky.org> <1402594327.20883.216.camel@revolution.hippie.lan> <5399E660.5050207@selasky.org> <5399E901.1080805@selasky.org> <5399FB57.8090102@rice.edu>
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On 06/12/14 21:11, Alan Cox wrote: > On 06/12/2014 12:53, Hans Petter Selasky wrote: >> On 06/12/14 19:41, Hans Petter Selasky wrote: >>> On 06/12/14 19:32, Ian Lepore wrote: >>>> On Thu, 2014-06-12 at 19:28 +0200, Hans Petter Selasky wrote: >>>>> On 06/12/14 19:12, Alan Cox wrote: >>>>>> On 06/12/2014 01:03, Hans Petter Selasky wrote: >>>>>>> On 06/11/14 22:47, Alan Cox wrote: >>>>>>>> >>>>>>>> On Jun 11, 2014, at 3:45 PM, Hans Petter Selasky wrote: >>>>>>>> >>>>>>>>> On 06/11/14 22:20, Alan Cox wrote: >>>>>>>>>> >>>>>>>>>> On Jun 11, 2014, at 3:07 PM, Hans Petter Selasky wrote: >>>>>>>>>> >>>>>>>>>>> kernel: file format elf32-littlearm >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Then this problem is unrelated to the one that I just fixed. >>>>>>>>>> It's >>>>>>>>>> also not a problem that I've seen before. >>>>>>>>> >>>>>>>>> It is happening after your recent patches to -current, optimising >>>>>>>>> the "page ordering". Happens every now and then during boot when >>>>>>>>> stack is growing looks like. >>>>>>>> >>>>>>>> More precisely, which commit is that? >>>>>>>> >>>>>>> >>>>>>>> commit 7d20e37fb658b0e2cd7f3c13dac8022e0e866a21 >>>>>>>> Author: alc <alc@FreeBSD.org> >>>>>>>> Date: Sun May 12 16:50:18 2013 +0000 >>>>>>>> >>>>>>>> Refactor vm_page_alloc()'s interactions with >>>>>>>> vm_reserv_alloc_page() and >>>>>>>> vm_page_insert() so that (1) vm_radix_lookup_le() is never >>>>>>>> called >>>>>>>> while the >>>>>>>> free page queues lock is held and (2) vm_radix_lookup_le() is >>>>>>>> called at most >>>>>>>> once. This change reduces the average time that the free >>>>>>>> page >>>>>>>> queues lock >>>>>>>> is held by vm_page_alloc() as well as vm_page_alloc()'s >>>>>>>> average >>>>>>>> overall >>>>>>>> running time. >>>>>>>> >>>>>>>> Sponsored by: EMC / Isilon Storage Division >>>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> That's not exactly a recent commit. It was 13 months ago. And, this >>>>>> code is exercised by all page allocations except for page table pages >>>>>> and uma_small_alloc(). >>>>>> >>>>>> What this assertion is telling us is that somewhere else we have >>>>>> screwed >>>>>> up the vm object to which we are now trying to allocate a page. >>>>>> >>>>>> Try the attached patch. It will provide additional information the >>>>>> next >>>>>> time that the assertion fails. >>>>>> >>>>> >>>>> Here you go: >>>>> >>>>>> panic: vm_page_insert_after: msucc 0xc0993e50 (0) doesn't succeed >>>>>> pindex 4 >>>>>> object 0xc1a2b140 type 0 >>>>>> KDB: enter: panic >>>>>> [ thread pid 18 tid 100052 ] >>>>>> Stopped at $d: ldrb r15, [r15, r15, ror r15]! >>>>>> db> >>>> >>>> Could this be related to changing superpages to enabled by default >>>> recently? Easy to test by setting vm.pmap.sp_enabled=0 in ubldr >>>> >>> >>> Setting the sp_enabled to 0 does not fix the problem. >>> >>> --HPS >> >> Output from the debugger regarding the object: >> >>> panic: vm_page_insert_after: msucc 0xc0993e50 (0) doesn't succeed >>> pindex 4 >>> object 0xc1a2b1e0 type 0 >>> KDB: enter: panic >> >>> db> show vmochk >>> vmochk: internal obj is not in a map: ref: 1, size: 2: 0x2, >>> backing_object: 0 >>> vmochk: internal obj is not in a map: ref: 1, size: 2: 0x2, >>> backing_object: 0 >> > > Use the ddb command "object", not "vmochk". > >> .... >> >>> db> show vmopag >> >> .... >> >>> new object: 0xc1a2b1e0 >>> index(0)run(1)pa(0x1766000) >>> index(1)run(1)pa(0x1e17000) >>> index(2)run(2)pa(0x1772000) >>> index(4)run(1)pa(0x1e6a000) >>> index(5)run(2)pa(0x1775000) >>> index(7)run(1)pa(0x1778000) >>> index(8)run(1)pa(0x1788000) >>> index(9)run(1)pa(0x17e9000) >> >> --HPS >> >> >> > > show object 0xc1a2b1e0 Object 0xc1a2b1e0: type=0, size=0xa, res=10, ref=2, flags=0x3000 ruid 0 charge a000 sref=0, backing_object(0)=(0)+0x0 memory:=(off=0x0,page=0x1766000),(off=0x1,page=0x1e17000),(off=0x2,page=0x1772000),(off=0x3,page=0x1773000),(off=0x4,page=0x1e6a000),(off=0x5,page=0x177500) ...(off=0x6,page=0x1776000),(off=0x7,page=0x1778000),(off=0x8,page=0x1788000),(off=0x9,page=0x17e9000)
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