[lkml]   [2005]   [Aug]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC] Demand faulting for large pages
On Fri, 5 Aug 2005, Andi Kleen wrote:

> > Unless I am missing something, the call to follow_hugetlb_page() in
> > get_user_pages() is just an optimization. Removing it means
> > follow_page() will be called individually for each PAGE_SIZE page in the
> > huge page. We can probably do better but I didn't want to cloud this
> > patch with that logic.
> The problem is that get_user_pages needs to handle the case of a large
> page not yet being faulted in properly. The SLES9 implementation did
> some changes for this.
> You don't change it at all, so I'm suspect it doesn't work yet.
> It's a common case - think people doing raw IO on huge pages shared memory.

Seems that follow_page calls follow_huge_addr for huge pages.
follow_huge_addr is arch specific and so we would need to verify that all
arches do the right things if the page is not present.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-08-05 19:14    [W:0.107 / U:2.480 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site