Abhijit Bhopatkar wrote:
In my mind i find it fundamentally wrong to separate anon pages from page cache. It should rather be lot more dependent on which task accessed them last. Although it seems due to some twisted relationships bet anon pages and interactive tasks separating them improves it. Am i missing something here?
The IO cost for anonymous (and other swap backed) pages is completely different from the IO cost of file system backed pages. On file systems, data is typically grouped together on disk by related content. Programs often access data linearly, meaning that with readahead we can load a lot of pages into memory with only a few disk seeks. Anonymous memory does not have this benefit. For one, memory tends to get written to swap by LRU order, not by related content. To make things worse, repeated malloc/free cycles can cause the memory adjacant to each other inside a process to be completely unrelated, making virtual address based swap clustering less useful. The goal of page replacement is to minimize the total time spent waiting on page faults. This is not exactly the same as minimizing the total number of page faults.
Can you send me those patches please or point me to where i can find those?
You can get the latest one here: http://surriel.com/patches/2.6/vm-split/linux-2.6-vm-split.patch -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic. - 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/