Hello, Eric! On 05/26/2011 12:13 PM, Eric B Munson wrote: > diff --git a/HOWTO b/HOWTO > index 3c1f124..b018543 100644 > --- a/HOWTO > +++ b/HOWTO > @@ -2,7 +2,7 @@ libhugetlbfs HOWTO > ================== > > Author: David Gibson<d...@au1.ibm.com>, Adam Litke<a...@us.ibm.com>, and > others > -Last updated: February 1st, 2011 > +Last updated: May 25th, 2011 > > Introduction > ============ > @@ -264,6 +264,11 @@ environment variables: > To use a specific huge page size: > HUGETLB_MORECORE=<pagesize> > > + To use Transparent Huge Pages (THP): > + HUGETLB_MORECORE=thp > + > +Note: This option requires a kernel that supports Transparent Huge Pages > + > Usually it's preferable to set these environment variables on the > command line of the program you wish to run, rather than using > "export", because you'll only want to enable the hugepage malloc() for > @@ -599,6 +604,10 @@ libhugetlbfs: > HUGETLB_NO_PREFAULT > Explained in "Using hugepages for malloc() > (morecore)" > + HUGETLB_THP_MADVISE > + When using thp for HUGETLB_MORECORE, this signals that > + allocations for the heap should use madvise(MADV_HUGEPAGE) to > + mark them as appropriate for collapsing by khugepaged
Probably just idle curiosity, but why would someone want to set HUGETLB_MORECORE=thp and not set HUGETLB_THP_MADVISE at the same time? Might it make sense for HUGETLB_MORECORE=thp to automatically turn on the madvise(MADV_HUGEPAGE)? If necessary, a separate env. var. could disable the automatic madvise. > @@ -220,7 +229,8 @@ void hugetlbfs_setup_morecore(void) > * This can be set explicitly by setting HUGETLB_MORECORE to a valid > * page size string or by setting HUGETLB_DEFAULT_PAGE_SIZE. > */ > - if (strncasecmp(__hugetlb_opts.morecore, "y", 1) == 0) > + if ((strncasecmp(__hugetlb_opts.morecore, "y", 1) == 0) || > + __hugetlb_opts.thp_morecore) > hpage_size = gethugepagesize(); > else > hpage_size = parse_page_size(__hugetlb_opts.morecore); thp_morecore should probably use kernel_default_hugepage_size() instead of gethugepagesize(). gethugepagesize() will use HUGETLB_DEFAULT_PAGE_SIZE if set. -Andrew Hastings Cray Inc. ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 _______________________________________________ Libhugetlbfs-devel mailing list Libhugetlbfs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libhugetlbfs-devel
