lkml.org 
[lkml]   [2011]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] mm: add a "struct page_frag" type containing a page, offset and length
From
Date
On Thu, 2011-10-13 at 22:22 +0100, Andrew Morton wrote:
> Looks OK to me. I'm surprised we don't already have such a thing.
>
> Review comments:
>
>
> > +struct page_frag {
> > + struct page *page;
> > +#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
>
> It does add risk that people will add compile warnings and bugs by
> failing to consider or test the other case.
>
> We could reduce that risk by doing
>
> #if (PAGE_SIZE >= 65536)
>
> but then the 32-bit version would hardly ever be tested at all.

Indeed. The first variant has the benefit that most 32-bit arches will
test one case and most 64-bit ones the other.

Perhaps the need to keep this struct small is not so acute as it is for
the skb_frag_t I nicked it from and just using __u32 unconditionally is
sufficient?

>
> > + __u32 page_offset;
>
> I suggest this be called simply "offset".

ACK.

Thanks,

Ian.




\
 
 \ /
  Last update: 2011-10-14 08:59    [W:0.122 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site