|
From: | Stefan Priebe |
Subject: | Re: [Qemu-devel] slow xbzrle |
Date: | Thu, 25 Oct 2012 22:45:41 +0200 |
User-agent: | Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/20121010 Thunderbird/16.0.1 |
Am 25.10.2012 15:15, schrieb Orit Wasserman:
Looks like a lot of cache miss, you can try increasing the cache size (migrate_set_cache_size). But you should remember that for an idle guest XBZRLE is wasteful, it is useful for workload that changes the same memory pages frequently.sure here are some values from a loaded VM (20% cpu load with MySQL) - with an increased cache size does not look much better: Oct 25 14:16:39 migration xbzrle cachesize: 536870912 transferred 0 pages 0 cachemiss 159634 overflow 0 Oct 25 14:16:41 migration xbzrle cachesize: 536870912 transferred 0 pages 0 cachemiss 173631 overflow 0 Oct 25 14:16:43 migration xbzrle cachesize: 536870912 transferred 0 pages 0 cachemiss 187627 overflow 0 Oct 25 14:16:45 migration xbzrle cachesize: 536870912 transferred 0 pages 0 cachemiss 201624 overflow 0It looks like the cache got smaller 1073741824 > 536870912 ... try 2G cache size Orit
Here from another VM running into overflow setting cache size to 50% of mem:Oct 25 22:43:57 migration xbzrle cachesize: 2147483648 transferred 36294204 pages 520357 cachemiss 392074 overflow 947
Oct 25 22:44:31 migration xbzrle cachesize: 2147483648 transferred 45438419 pages 653350 cachemiss 392091 overflow 1024
Oct 25 22:44:55 migration xbzrle cachesize: 2147483648 transferred 51310028 pages 742877 cachemiss 392096 overflow 1054
Greets, Stefan
[Prev in Thread] | Current Thread | [Next in Thread] |