Hi Rik > While being able to deal with used-once mappings in page reclaim > could be a good idea, this would require us to be able to determine > the difference between a page that was accessed once since it was > faulted in and a page that got accessed several times.
it makes sense that read ahead hit assume used-once mapping, may be. I will try it. (may be, i can repost soon) > Given that page faults have overhead too, it does not surprise me > that read+write is faster than mmap+memcpy. > > In threaded applications, page fault overhead will be worse still, > since the TLBs need to be synchronized between CPUs (at least at > reclaim time). sure. but current is unnecessary large performance difference. I hope improvement it because copy by mmapd is very common operation. > Maybe we should just advise people to use read+write, since it is > faster than mmap+memcpy? Time is solved to it :) thanks! - kosaki -- 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/
