On 16.08.2006 [10:11:37 +0100], Andy Whitcroft wrote: > Nishanth Aravamudan wrote: > >morecore's comments indicate that we will failover to smallpage malloc > >if we run out of hugepages at runtime, but that is not the case. Modify > >one comment and remove another to not confuse anyone. > > > >Signed-off-by: Nishanth Aravamudan <[EMAIL PROTECTED]> > > > >diff --git a/morecore.c b/morecore.c > >index 9f13316..08a356b 100644 > >--- a/morecore.c > >+++ b/morecore.c > >@@ -45,8 +45,8 @@ static long mapsize; > > * pretend there are none this covers us for the case where another > > * map is in the way. This is required because 'morecore' must have > > * 'sbrk' semantics, ie. return sequential, contigious memory blocks. > >- * Luckily, if it does not do so and we error out malloc will happily > >- * go back to small pages and use mmap to get them. Hurrah. > >+ * Sufficient hugepages must be allocated before the malloc calls, or > >+ * the application will be killed. > > Hmmm, that is a tricky one. If morecore does return failure then the > malloc library will do all the things mentioned. The problem here is > that with demand fault semantics we will say 'yes' and return a page > which can't be instantiated. > > The comment in and of itsself is correct IMO. Your caveat is > appropriate though in addition.
Description: morecore's comments indicate that we will failover to smallpage malloc if we run out of hugepages at runtime. While that is the case, the semantics of demand faulting require sufficient hugepages exist before the malloc calls. Add a comment to that effect to make it clear. Signed-off-by: Nishanth Aravamudan <[EMAIL PROTECTED]> diff --git a/morecore.c b/morecore.c index 9f13316..4b222ed 100644 --- a/morecore.c +++ b/morecore.c @@ -46,7 +46,9 @@ static long mapsize; * map is in the way. This is required because 'morecore' must have * 'sbrk' semantics, ie. return sequential, contigious memory blocks. * Luckily, if it does not do so and we error out malloc will happily - * go back to small pages and use mmap to get them. Hurrah. + * go back to small pages and use mmap to get them. Hurrah. However, + * sufficient hugepages must be allocated before the malloc calls, or + * the application will be killed. */ static void *hugetlbfs_morecore(ptrdiff_t increment) -- Nishanth Aravamudan <[EMAIL PROTECTED]> IBM Linux Technology Center ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Libhugetlbfs-devel mailing list Libhugetlbfs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libhugetlbfs-devel
