Re: [PATCH 10 of 20] ipath - support for userspace apps using coredriver

[Hugh Dickins]

On Thu, 16 Mar 2006, Bryan O'Sullivan wrote:
> 
> OK.  Would it be correct to say that this is what we should do, then?
> 
>       * On 2.6.15 and later kernels, use __GFP_COMP at allocation time,
>         and get_page in ->nopage.  This is what we're doing as of this
>         morning, and it works.
>       * For backports to 2.6.14 and earlier, avoid __GFP_COMP, mark each
>         page with SetPageReserved at allocation time, and do nothing
>         special in ->nopage.  Do we need to ClearPageReserved before
>         freeing?

Yes, I believe that's exactly right - so long as you do ClearPageReserved
from each of its constituent 0-order-pages before freeing the >0-order
page, in the <= 2.6.14 case.

You wisely remarked earlier that you'd not yet checked for memory leaks:
that is of course the complementary, less obvious, error to the troubles
you've been having so far: and I wish you luck when you come to check,
hoping that I haven't merely misled you from one side to the other!

Hugh
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/