Re: Page Allocation Failure, Why?? Bug in kernel??

["Dave Airlie" <airlied@gmail.com>]

Fragmentation.

you have 32-pages scattered around the place, they are not in the one
place, you are asking for 32-contiguous pages, you cannot get this as
the memory is fragmented.

you should really never try allocating that many contiguous pages.

Dave.

On 6/2/06, Abu M. Muttalib <abum@aftek.com> wrote:
> Hi,
>
> I repeat my question, the required no of pages are available, as shown in
> the dump produced by kernel, the request is not fulfilled. Its as follows:
>
> DMA: 106*4kB 11*8kB 5*16kB 3*32kB 2*64kB 1*128kB 0*256kB 0*512kB 0*1024kB =
> 944kB
>
> Why this is so??
>
> ~Abu.
>
> -----Original Message-----
> From: Jesper Juhl [mailto:jesper.juhl@gmail.com]
> Sent: Friday, June 02, 2006 12:36 PM
> To: Abu M. Muttalib
> Cc: Martin J. Bligh; Paulo Marques; linux-kernel@vger.kernel.org
> Subject: Re: Page Allocation Failure, Why?? Bug in kernel??
>
>
> On 02/06/06, Abu M. Muttalib <abum@aftek.com> wrote:
> > Hi,
> >
> > That's precisely I want to say. The PAGES are available but they are not
> > allocated to process. Why??
> >
> There may be 32 pages available in total, but not 32 contiguous ones -
> that's a *lot* of contiguous pages to ask for in kernel space - 128KB
> (assuming a 4096 byte page size).
>
> --
> Jesper Juhl <jesper.juhl@gmail.com>
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