On 05/13/2015 04:38 PM, Michal Hocko wrote: > From: Michal Hocko <mhocko@xxxxxxx> > > David Rientjes has noticed that MAP_POPULATE wording might promise much > more than the kernel actually provides and intend to provide. The > primary usage of the flag is to pre-fault the range. There is no > guarantee that no major faults will happen later on. The pages might > have been reclaimed by the time the process tries to access them. Yes, thanks, Michal -- that's a good point to make clearer. Applied, with Reviewed-by: from Eric added. Cheers, Michael > Signed-off-by: Michal Hocko <mhocko@xxxxxxx> > --- > man2/mmap.2 | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/man2/mmap.2 b/man2/mmap.2 > index 1486be2e96b3..dcf306f2f730 100644 > --- a/man2/mmap.2 > +++ b/man2/mmap.2 > @@ -284,7 +284,7 @@ private writable mappings. > .BR MAP_POPULATE " (since Linux 2.5.46)" > Populate (prefault) page tables for a mapping. > For a file mapping, this causes read-ahead on the file. > -Later accesses to the mapping will not be blocked by page faults. > +This will help to reduce blocking on page faults later. > .BR MAP_POPULATE > is supported for private mappings only since Linux 2.6.23. > .TP > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>