lkml.org 
[lkml]   [2010]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [2.6.35-rc3] select useful number of entries for DMA debugging...
From
On 9 July 2010 22:33, Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Mon, Jul 5, 2010 at 1:35 AM, Daniel J Blueman
> <daniel.blueman@gmail.com> wrote:
>> When booting 2.6.35-rc3 on some different x86 boxes with DMA debugging
>> enabled, I've consistently seen it exhaust the allocated entries during
>> boot, giving 'DMA-API: debugging out of memory - disabling'.
>>
>> Increase number of entries to allow DMA debugging again.
>
> Rather than increase the default that gets allocated whenever anybody
> enables the DMA debugging, I'd really prefer to see people use the
> kernel command line option if they run out. After all, it's a (pretty
> esoteric) debug option, and the number of required entries depends on
> machine configuration. I'd rather not make the default cover a huge
> number, when you could just add
>
>   dma_debug_entries=65536
>
> on the kernel boot command line instead for machines that want/need it..

That said, I am seeing the DMA pool exhaust on a single socket Core i5
system with Intel graphics and no other adapters - seems like a fairly
common case. If eg 25% of developers will be using similar to this,
maybe it's good to make DMA debugging less immediately esoteric?

On the other hand, I would immediately agree if the exhaustion
occurred on an atypical setup.
--
Daniel J Blueman
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-07-10 16:55    [W:0.039 / U:0.420 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site