[ELDK] Jumbo Frames, sil24 SATA driver, and kswapd0 page allocation failures

Wolfgang Denk wd at denx.de
Wed Aug 12 23:18:55 CEST 2009

Dear Jonathan Haws,

In message <BB99A6BA28709744BF22A68E6D7EB51F01FE4C8FDB at midas.usurf.usu.edu> you wrote:
> > This is pure speculation, without any facts to base it on, right?
> Yes, you are right.  This is speculation.  I have been searching online for
>  answers for the past three days trying to figure out what could be causing
>  this issue.

Could you *please* restrict your line length to some 70 characters or
so?  Thanks.

> Everything seems to point to the fact that when write() is called, memory i
> s allocated from RAM to cache data before it is physically written to disk.
>   However, it appears (again, I am speculating here - if someone can enligh
> ten me that would be great) that memory is not getting released - simply be
> cause when the emac_poll_rx tries to allocate memory for its next skb it fa
> ils and for all intents and purposes crashes the kernel.
> I am almost certain that the issue is not in my code, but in the kernel som
> ewhere.  But digging through libAta, I do not find anything that would caus
> e this.  It appears that when memory is allocated, it is released as soon a
> t it is finished using it.

Well, it would be definitely helpful if you first checked your code
and added proper error checking to all system calls and library
function calls, and bail out after an error occurs.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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