Date: Sat, 9 Jan 2016 15:36:09 -0600 From: Alan Cox <alc@rice.edu> To: Adrian Chadd <adrian.chadd@gmail.com>, John Baldwin <jhb@freebsd.org> Cc: freebsd-current <freebsd-current@freebsd.org>, Cy Schubert <Cy.Schubert@komquats.com>, Jeremie Le Hen <jlh@freebsd.org>, Ryan Stone <rysto32@gmail.com>, =?UTF-8?Q?Jean-S=c3=a9bastien_P=c3=a9dron?= <dumbbell@freebsd.org>, "?Alan L. Cox" <alc@freebsd.org> Subject: Re: Panic from vesa_configure() Message-ID: <56917D49.1000707@rice.edu> In-Reply-To: <56916800.7060109@rice.edu> References: <201601070947.u079lWFk066644@slippy.cwsent.com> <6763716.RJFa7H2OmF@ralph.baldwin.cx> <CAJ-Vmokd==2LU7k0MGB2M494b4Y-PD9rCykyD8DW87oZiG7sAg@mail.gmail.com> <56916800.7060109@rice.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
This is a multi-part message in MIME format.
--------------080104010900060709060805
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
On 01/09/2016 14:05, Alan Cox wrote:
> On 01/09/2016 13:48, Adrian Chadd wrote:
>> On 9 January 2016 at 11:30, John Baldwin <jhb@freebsd.org> wrote:
>>> On Thursday, January 07, 2016 01:47:32 AM Cy Schubert wrote:
>>>> In message <CAGSa5y0QiKV9SgJYJ_mz3SnJGNjieHSvYP8nLjt9eWXo4RU6ww@mail.gmail.c
>>>> om>
>>>> , Jeremie Le Hen writes:
>>>>> On Mon, Dec 21, 2015 at 12:57 AM, Adrian Chadd <adrian.chadd@gmail.com> wrote
>>>>> :
>>>>>> can you copy/paste the file:line that each of those stackframes represents?
>>>>>>
>>>>>> I may have an idea or two..
>>>>> Sure here we go:
>>>>>
>>>>> (kgdb) list *vesa_configure+0x270
>>>>> 0xffffffff80b25cd0 is in vesa_configure (/usr/src-svn/sys/dev/fb/vesa.c:827).
>>>>>
>>>>> (kgdb) list *vga_init+0x65
>>>>> 0xffffffff80b286e5 is in vga_init (/usr/src-svn/sys/dev/fb/vga.c:1402).
>>>>>
>>>>> (kgdb) list *isavga_attach+0x92
>>>>> 0xffffffff80b9afd2 is in isavga_attach (/usr/src-svn/sys/isa/vga_isa.c:224).
>>>> Here is what I see. Only happens on real hardware (not VirtualBox VMs).
>>>>
>>>> uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
>>>> uart0: console (9600,n,8,1)
>>>> acpi_alloc_wakeup_handler: can't alloc wake memory
>>> This is probably related to the same cause. Both this and the x86 BIOS stuff
>>> need "low" memory (memory below 1MB).
>>>
>>> x86bios_alloc() uses contigmalloc() as does acpi_alloc_wakeup_handler().
>>> Perhaps the recent changes to contigmalloc() affect this? In particular,
>>> try reverting r292469 to see if that fixes the issue.
>> Can't we just keep a pool of those pages around and not give them out
>> unless someone specifically asks for low memory?
> vm_phys.c already implements a "soft segregation" under which these
> pages are only allocated as a last resort, unless
> kmem_alloc_{attr,contig}() or contigmalloc() is called.
>
> What happened is that r292469 changed the order in which we pull from
> the free lists for kmem_alloc_{attr,contig}() and contigmalloc() so that
> a bunch of, for example, contigmalloc(low=0, high=4GB) calls, could
> potentially exhaust physical memory in the range [0, 1MB). In other
> words, we're no longer getting the soft segregation among contigmalloc()
> calls.
>
This patch should suffice to restore the soft segregation among
contigmalloc() calls.
--------------080104010900060709060805
Content-Type: text/plain; charset=UTF-8;
name="vm_phys_alloc_contig2.patch"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename="vm_phys_alloc_contig2.patch"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--------------080104010900060709060805--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?56917D49.1000707>