intelfb stack usage

intelfb stack usage

[Randy.Dunlap]

In 2.6.10-rc3-bk6, intelfb_set_par() has the distinction of being
the largest stack user as determined by 'make checkstack':

objdump -d vmlinux $(find . -name '*.ko') | \
perl /mnt/src/linux-2610-rc3-bk6/scripts/checkstack.pl i386
0x00001317 intelfb_set_par:				2404

because it has this large struct on the stack:
	struct intelfb_hwstate hw;
(almost 2400 bytes)

Any suggestions for how to alleviate this large stack usage?

 From a quick look, this is called from fb_ioctl() to fb_set_var()
to fb_set_par().
fb_ioctl() does acquire_console_sem(), so using kmalloc()
here would need to use GFP_ATOMIC...
I can do that if it's desired & acceptable.

-- 
~Randy


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Re: intelfb stack usage

[Antonino A. Daplas]

On Saturday 18 December 2004 03:17, Randy.Dunlap wrote:
> In 2.6.10-rc3-bk6, intelfb_set_par() has the distinction of being
> the largest stack user as determined by 'make checkstack':
>
> objdump -d vmlinux $(find . -name '*.ko') | \
> perl /mnt/src/linux-2610-rc3-bk6/scripts/checkstack.pl i386
> 0x00001317 intelfb_set_par:				2404
>
> because it has this large struct on the stack:
> 	struct intelfb_hwstate hw;
> (almost 2400 bytes)
>
> Any suggestions for how to alleviate this large stack usage?
>
>  From a quick look, this is called from fb_ioctl() to fb_set_var()
> to fb_set_par().
> fb_ioctl() does acquire_console_sem(), so using kmalloc()
> here would need to use GFP_ATOMIC...
> I can do that if it's desired & acceptable.

Using kmalloc() should be acceptable.  I'll CC the author.

Tony




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Re: intelfb stack usage

[Sylvain Meyer]

        If you can do it, thanks. I won't have any time until next year.

Sylvain

Antonino A. Daplas a écrit:

>On Saturday 18 December 2004 03:17, Randy.Dunlap wrote:
>  
>
>>In 2.6.10-rc3-bk6, intelfb_set_par() has the distinction of being
>>the largest stack user as determined by 'make checkstack':
>>
>>objdump -d vmlinux $(find . -name '*.ko') | \
>>perl /mnt/src/linux-2610-rc3-bk6/scripts/checkstack.pl i386
>>0x00001317 intelfb_set_par:				2404
>>
>>because it has this large struct on the stack:
>>	struct intelfb_hwstate hw;
>>(almost 2400 bytes)
>>
>>Any suggestions for how to alleviate this large stack usage?
>>
>> From a quick look, this is called from fb_ioctl() to fb_set_var()
>>to fb_set_par().
>>fb_ioctl() does acquire_console_sem(), so using kmalloc()
>>here would need to use GFP_ATOMIC...
>>I can do that if it's desired & acceptable.
>>    
>>
>
>Using kmalloc() should be acceptable.  I'll CC the author.
>
>Tony
>
>
>
>
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>SF email is sponsored by - The IT Product Guide
>Read honest & candid reviews on hundreds of IT Products from real users.
>Discover which products truly live up to the hype. Start reading now. 
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>
>  
>





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