On Wed, 29 Aug 2007 09:29:32 -0400 Daniel Drake <[EMAIL PROTECTED]> wrote:
Hi, > I've spent some time trying to understand why swapoff is such a slow > operation. > > My experiments show that when there is not much free physical memory, > swapoff moves pages out of swap at a rate of approximately 5mb/sec. sounds like about disk speed (at random-seek IO pattern) > I'm happy to spend a few more hours looking into implementing this but > would greatly appreciate any advice from those in-the-know on if my > ideas are broken to start with... before you go there... is this a "real life" problem? Or just a mostly-artificial corner case? (the answer to that obviously is relevant for the 'should we really care' question) Another question, if this is during system shutdown, maybe that's a valid case for flushing most of the pagecache first (from userspace) since most of what's there won't be used again anyway. If that's enough to make this go faster... A third question, have you investigated what happens if a process gets killed that has pages in swap; as long as we don't page those in but just forget about them, that would solve the shutdown problem nicely (since we kill stuff first anyway there) - 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/
