On Wed, 19 May 2010, Mathieu Desnoyers wrote: > > Programs can use posix_fadvise() to announce an intention to access > file data in a specific pattern in the future, thus allowing the kernel > to perform appropriate optimizations. It's true for some of them. The random-vs-linear behavior is a flag for the future, for example (relevant for prefetching). In fact, it's technically true even for DONTNEED. It's true that we won't need the pages in the future! So we throw the pages away. But that means that we throw the _current_ pages away. If we actually touch pages later, than that obviously invalidates the fact that we said 'DONTNEED' - we clearly needed them. Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>