On Fri, 2007-04-20 at 12:10 -0700, Christoph Lameter wrote:
> On Fri, 20 Apr 2007, Dave Kleikamp wrote:
> > Yeah. I'm working on patches for storing file tails in buffers
> > allocated from the slab cache, and the tail will be represented by a
> > fake struct page. (This is primarily for kernels with a larger page
> > size). So my version of page_cache_size(page) may return a different
> > size for different pages belonging to the same mapping. I'm in the
> > midst of cleaning up the patches and plan to post them to linux-mm by
> > Monday.
>
> I am not sure what the point of that patchset would be in this context
> given that this is about support for arbitrary page sizes. If the
> filesystem wants it then it can reduce the page size for small files.
>
> Different page sizes for one mapping may introduce high complexity into a
> filesystem.
I'm trying to keep it from getting too complicated.
> And we can already represent different page size. We have compound pages
> support in the kernel.
There are advantages to having a larger base page size, such as
increased TLB reach. I'm specifically targetting kernels built with
CONFIG_PPC_64K_PAGES, but other architectures could benefit.
> page_cache_size(page) in terms of current code in mm is
>
> PAGE_SIZE << compound_order(page)
I don't see page_cache_size() in linux-2.6.21-rc6-mm1. Is there
something newer?
Anyway, my patches are at a proof-of-concept stage. I look forward to
more discussion when I post the patch set.
Thanks,
Shaggy
--
David Kleikamp
IBM Linux Technology Center
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
