|
From: | Paolo Bonzini |
Subject: | Re: [Qemu-devel] [PATCH 1/1] Count used RAMBlock pages for migration_dirty_pages |
Date: | Fri, 21 Mar 2014 16:49:05 +0100 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 |
Il 21/03/2014 16:45, Dr. David Alan Gilbert ha scritto:
> So it looks like your patch could also fix the problem Juan reported > at http://article.gmane.org/gmane.comp.emulators.qemu/247462 -- but > perhaps only on hosts where !KVM || TARGET_PAGE_SIZE==getpagesize().Possibly yes; I think that would cause gaps in the bitmap to have the same effect as the hot unplug.
It would be nice to revive that patch, because without it you risk getting bad performance from migration of hotplugged memory. On-board RAM typically gets low ram_addr_t's that are aligned, but the 128K (32 pages) ROM and the 64K VGA BIOS will ruin the alignment and cause migration to use the slow paths to migrate hotplugged memory above them.
Paolo
I'll rework the patch to my less paranoid version from yesterday that treats bitmap bits as belonging to only one RAMBlock and repost.
[Prev in Thread] | Current Thread | [Next in Thread] |