It is not obvious from the interface that partial page discard requests are ignored. It should be spelled out. Signed-off-by: Mel Gorman <mgorman@xxxxxxx> --- man2/posix_fadvise.2 | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/man2/posix_fadvise.2 b/man2/posix_fadvise.2 index 25d0c50..07313a9 100644 --- a/man2/posix_fadvise.2 +++ b/man2/posix_fadvise.2 @@ -144,6 +144,11 @@ A program may periodically request the kernel to free cached data that has already been used, so that more useful cached pages are not discarded instead. +Requests to discard partial pages are ignored. It is preferable to preserve +needed data than discard unneeded data. If the application requires that +data be considered for discarding then \fIoffset\fP and \fIlen\fP must be +page-aligned. + Pages that have not yet been written out will be unaffected, so if the application wishes to guarantee that pages will be released, it should call -- 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>