Hi. On Sat, 2007-04-07 at 15:06 -0700, Andrew Morton wrote: > On Sat, 7 Apr 2007 23:20:39 +0200 "Rafael J. Wysocki" <[EMAIL PROTECTED]> > wrote: > > > This should allow us to reduce the memory usage, practically always, and > > improve performance. > > And does it?
It will. I've been using extents for ages, for the same reasons. I don't put them in an rb_tree because I view it as less than most efficient, but it will still be a huge step forward from bitmaps in the normal case. The worst case would be if every second page of swap was in use, so that you needed one extent per swap page. In that case, it would use more memory than the bitmap, but far, far more common will be the case where only one extent is needed for the whole swap partition, because the algorithm used by the swap allocator minimises fragmentation. Regards, Nigel - 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/
