On Wed, Jun 22, 2011 at 4:07 PM, Bill Holder <hold...@us.ibm.com> wrote: >> But since Linux does know how to evacuate swap space, you can define a >> new VDISK for swap and free the old VDISK. Once you detach it, the >> slots on page space will be freed up. Whether it makes sense to shake >> up your memory reference patterns like that is an entirely different >> issue... >> >> | Rob > > Ok, I had forgotten Linux could do that, so that could get all of the > vdisk pages moved (assuming there are no other vdisk uses), but it > does "stir the pot" in terms of recency of reference (all of those > pages have to become resident and then age back out through the > paging hierarchy (which isn't ideal), and it won't get other types > of CP owned pages, but it might be enough for some shops.
Right, you'd have to be careful since you (briefly) increase your memory requirement. I only recommend that when the cause of the swapping is gone already and Linux has released most slots on the swap disk again. CP would continue to care for the pages even though Linux does not need the contents. In that case there's little stirring and the benefit is that CP can then release the backing of the VDISK. PS Instead of the discussed wibni's, I'd rather have DIAG10 for VDISK on the wish list (call it CMM-3 if that looks better on your PBC). The things in Linux to exploit that are mostly there (aka TRIM support for SSD devices). | Rob ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
