On Tue, 2018-03-06 at 16:23 -0800, Andrew Morton wrote:
(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Sat, 24 Feb 2018 03:56:38 +0000 bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote:https://bugzilla.kernel.org/show_bug.cgi?id=198913 Bug ID: 198913 Summary: Swapping slows to about 20% of expected speed when using multiple swap partitions on separate drives (striping). ... Problems 1) Linux's swap striping on nine drives performs at only 19.5% of the speed of a memory-mapped file on a RAID 0 partition on the same nine drives. 2) Linux's swap striping performs best with exactly four swap partitions and performs almost as well with just three partitions.Well that's interesting, thanks. Let's get this onto the mm developers' mailing list and perhaps someone will have a theory. And perhaps Hugh will have a think about it when he returns to the fold.
Thanks, if let me know if you need me to run some test code or something.
