From: David Hildenbrand <david@redhat.com>
To: Peter Xu <peterx@redhat.com>
Cc: "Wang, Wei W" <wei.w.wang@intel.com>,
"mst@redhat.com" <mst@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"dgilbert@redhat.com" <dgilbert@redhat.com>,
"quintela@redhat.com" <quintela@redhat.com>
Subject: Re: [PATCH v3] migration: clear the memory region dirty bitmap when skipping free pages
Date: Fri, 23 Jul 2021 09:50:18 +0200 [thread overview]
Message-ID: <087670b0-d28c-7f3d-caf4-f37acf8f7d7e@redhat.com> (raw)
In-Reply-To: <YPmt3vrn5MfH6I13@t490s>
On 22.07.21 19:41, Peter Xu wrote:
> On Thu, Jul 22, 2021 at 04:51:48PM +0200, David Hildenbrand wrote:
>> I'll give it a churn.
>
> Thanks, David.
>
Migration of a 8 GiB VM
* within the same host
* after Linux is up and idle
* free page hinting enabled
* after dirtying most VM memory using memhog
* keeping bandwidth set to QEMU defaults
* On my 16 GiB notebook with other stuff running
Current upstream with 63268c4970a, without this patch:
total time: 28606 ms
downtime: 33 ms
setup: 3 ms
transferred ram: 3722913 kbytes
throughput: 1066.37 mbps
remaining ram: 0 kbytes
total ram: 8389384 kbytes
duplicate: 21674 pages
skipped: 0 pages
normal: 928866 pages
normal bytes: 3715464 kbytes
dirty sync count: 5
pages-per-second: 32710
Current upstream without 63268c4970a, without this patch:
total time: 28530 ms
downtime: 277 ms
setup: 4 ms
transferred ram: 3726266 kbytes
throughput: 1070.21 mbps
remaining ram: 0 kbytes
total ram: 8389384 kbytes
duplicate: 21890 pages
skipped: 0 pages
normal: 929702 pages
normal bytes: 3718808 kbytes
dirty sync count: 5
pages-per-second: 32710
Current upstream without 63268c4970a, with this patch:
total time: 5115 ms
downtime: 37 ms
setup: 5 ms
transferred ram: 659532 kbytes
throughput: 1057.94 mbps
remaining ram: 0 kbytes
total ram: 8389384 kbytes
duplicate: 20748 pages
skipped: 0 pages
normal: 164516 pages
normal bytes: 658064 kbytes
dirty sync count: 4
pages-per-second: 32710
Current upstream with 63268c4970a, with this patch:
total time: 5205 ms
downtime: 45 ms
setup: 3 ms
transferred ram: 659636 kbytes
throughput: 1039.39 mbps
remaining ram: 0 kbytes
total ram: 8389384 kbytes
duplicate: 20264 pages
skipped: 0 pages
normal: 164543 pages
normal bytes: 658172 kbytes
dirty sync count: 4
pages-per-second: 32710
I repeated the last two measurements two times and took the "better"
results.
Looks like this patch does it job and that 63268c4970a doesn't seem to
degrade migration in this combination/setup significantly (if at all, we
would have to do more measurements).
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-07-23 7:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-22 8:30 [PATCH v3] migration: clear the memory region dirty bitmap when skipping free pages Wei Wang
2021-07-22 9:47 ` David Hildenbrand
2021-07-22 9:57 ` Wang, Wei W
2021-07-22 14:51 ` Peter Xu
2021-07-22 14:51 ` David Hildenbrand
2021-07-22 17:41 ` Peter Xu
2021-07-23 7:50 ` David Hildenbrand [this message]
2021-07-23 8:14 ` Wang, Wei W
2021-07-23 8:16 ` David Hildenbrand
2021-07-23 8:32 ` Wang, Wei W
2021-07-23 12:51 ` Peter Xu
2021-07-23 12:52 ` David Hildenbrand
2021-07-23 8:03 ` David Hildenbrand
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