On Thu, 2 Apr 2015, David Rientjes wrote: > Don't only specify munmap(2) behavior with respect the hugetlb memory, all > other syscalls get naturally aligned to the native page size of the > processor. Rather, pick out munmap(2) as a specific example. > > Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Thanks, yes, good wording: it is best to be a bit vague here, since each msyscall takes the approach most convenient for it. Acked-by: Hugh Dickins <hughd@xxxxxxxxxx> > --- > Documentation/vm/hugetlbpage.txt | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt > index 1270fb1..030977f 100644 > --- a/Documentation/vm/hugetlbpage.txt > +++ b/Documentation/vm/hugetlbpage.txt > @@ -313,8 +313,11 @@ into /proc/sys/vm/hugetlb_shm_group. It is possible for same or different > applications to use any combination of mmaps and shm* calls, though the mount of > filesystem will be required for using mmap calls without MAP_HUGETLB. > > -When using munmap(2) to unmap hugetlb memory, the length specified must be > -hugepage aligned, otherwise it will fail with errno set to EINVAL. > +Syscalls that operate on memory backed by hugetlb pages only have their lengths > +aligned to the native page size of the processor; they will normally fail with > +errno set to EINVAL or exclude hugetlb pages that extend beyond the length if > +not hugepage aligned. For example, munmap(2) will fail if memory is backed by > +a hugetlb page and the length is smaller than the hugepage size. > > > Examples -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
