Re: insmod search_exception_table !!!

Re: insmod search_exception_table !!!

[Matt Porter]

On Tue, Apr 08, 2003 at 09:40:37PM +0530, invictus rm wrote:
>
> Hi ,
> I am working on a board which has 512MB RAM . The PCI space is from
> 0xe0000000 to 0xf8000000.
> 0xf8000000 -- 0xfc000000 device 1
> Remaining for other I/0(Flash/RTC..etc)
>
> When i try to load any module(insmod), the kernel crashes every time .

Sounds like you clobbered vmalloc space.  Did you use io_block_map()
calls and limit the amount of vmalloc space available?  How much
address space have you ioremapped before loading the module?

Assuming you aren't using any advanced options to change PAGE_OFFSET
and friends, your vmalloc space starts at 0xe1000000.  I sure hope
you haven't 1:1 mapped that PCI mem space into kernel virtual space.

Regards,
--
Matt Porter
porter@cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: insmod search_exception_table !!!

[Matt Porter]

On Tue, Apr 08, 2003 at 10:08:35PM +0530, invictus rm wrote:
> Hi Matt,
> I am using io_block_mapping for early_console_prints
>     io_block_mapping(0xf0000000, 0xf0000000, 0x10000000, _PAGE_IO);
>
> Is this a cause of the problem ??

Not on its own...you should have ~240MB of initial vmalloc space with
this configuration.

> How do i know how much addr i have ioremapped ??

You really want to know how much vmalloc space has been consumed
by all users.

Hard way:

Count all the ioremaps you do (plus 4KB offset between each
vmalloc offset).  If you are on a non-coherent platform you also
have to consider all consistent alloced memory.

Easy way:
ftp://source.mvista.com/pub/linuxppc/vmalloc_stats-2_4_devel.patch
/proc/meminfo contains vmalloc usage stats.

> My PAGE_OFFSET is at 0xc0000000
>
> Do i need to change the PCI MEM Map also if i am having a 1:1 mapping in the
> kernel virtual space ??

No, you just need to be aware that VMALLOC_END=ioremap_bot and this
value is set to whatever your lowest io_block_map virtual address is.
Any early ioremaps (pre-MM initialized) you do to place system devices
will further drop VMALLOC_END and constrain your vmalloc space.

Regards,
--
Matt Porter
porter@cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: insmod search_exception_table !!!

[Matt Porter]

On Wed, Apr 09, 2003 at 06:58:39PM +0530, invictus rm wrote:
> VmallocTotal:   245760 kB
> VmallocUsed:         0 kB
> VmallocChunk:   245760 kB
>
> VmallocUsed is 0 so looks like there is vmalloc space.

Yep, looks good.

> What can be the problem then ??

Any number of things.  It's hard to tell from the information
provided.  I suggest you compare what you've done on your port
to another working port with the same system controller (if classic
PPC) or the same SoC if it's 82xx/4xx.

Regards,
--
Matt Porter
porter@cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/