> > I cc'd linux-mm to see if there might be an interest in this ... or even > > if it's worth it: I can also see we don't necessarily want userspace to > > be able to tamper with our idea of what's hot and cold in the page > > cache, since we get it primarily from the lru lists. > > > > James The notion of hor and cold in the page allocator refers to processor cache hotness and is used for pages on the per cpu free lists. F.e. cold pages are used when I/O is soon expected to occur on them because we want to avoid having to evict cache lines. Cold pages have been freed a long time ago. Hot pages are those that have been recently freed (we know that some cachelines are present therefore) and thus it is likely that acquisition by another process will allow that process to reuse the cacheline already present avoiding a trip to memory. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html