On Wed, 4 Apr 2007, Marko Macek wrote: > Ulrich Drepper wrote: > > A solution for this problem is a madvise() operation with the following > > property: > > > > - the content of the address range can be discarded > > > > - if an access to a page in the range happens in the future it must > > succeed. The old page content can be provided or a new, empty page > > can be provided > > Doesn't this conflict with disabling overcommit? > > If the page is guaranteed to be available, obviously it must count as > being commited, so this is not equivalent to real freeing.
No, there's no conflict with disabled overcommit here: Committed_AS accounting is done on the whole vma size (at mmap or brk time), no matter how many pages may or may not be faulted in later. Rather like RLIMIT_AS. The proposed madvise operation won't affect it. (But I take Ulrich's "must succeed" with one pinch of salt: Out-Of-Memory killing remains a possibility, of course.) Hugh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
