[lkml]   [2019]   [Jan]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [LSF/MM TOPIC] NUMA remote THP vs NUMA local non-THP under MADV_HUGEPAGE
On 1/29/19 3:40 PM, Andrea Arcangeli wrote:
> In addition to the above "NUMA remote THP vs NUMA local non-THP
> tradeoff" topic, there are other developments in "userfaultfd" land that
> are approaching merge readiness and that would be possible to provide a
> short overview about:
> - Peter Xu made significant progress in finalizing the userfaultfd-WP
> support over the last few months. That feature was planned from the
> start and it will allow userland to do some new things that weren't
> possible to achieve before. In addition to synchronously blocking
> write faults to be resolved by an userland manager, it has also the
> ability to obsolete the softdirty feature, because it can provide
> the same information, but with O(1) complexity (as opposed of the
> current softdirty O(N) complexity) similarly to what the Page
> Modification Logging (PML) does in hardware for EPT write accesses.

I would be interested in this topic as well. IIRC, Peter's patches do
not address hugetlbfs support. I put together patches for this some
time back. At the time, they worked as well as userfaultfd-WP support
for normal base pages: not too well :). Once base page support is
finalized, I suspect I will be involved in hugetlbfs support.

Mike Kravetz

 \ /
  Last update: 2019-01-31 00:14    [W:0.079 / U:2.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site