From: David Hildenbrand <david@redhat.com>
To: Tyler Sanderson <tysand@google.com>,
"Michael S. Tsirkin" <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
virtualization@lists.linux-foundation.org,
Wei Wang <wei.w.wang@intel.com>,
Alexander Duyck <alexander.h.duyck@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Nadav Amit <namit@vmware.com>, Michal Hocko <mhocko@kernel.org>
Subject: Re: [PATCH v1 3/3] virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM
Date: Mon, 9 Mar 2020 10:03:14 +0100 [thread overview]
Message-ID: <86453fed-1f39-dfcc-33c6-54241478e2ab@redhat.com> (raw)
In-Reply-To: <CAJuQAmphPcfew1v_EOgAdSFiprzjiZjmOf3iJDmFX0gD6b9TYQ@mail.gmail.com>
On 08.03.20 05:47, Tyler Sanderson wrote:
> Tested-by: Tyler Sanderson <tysand@google.com>
>
> Test setup: VM with 16 CPU, 64GB RAM. Running Debian 10. We have a 42
> GB file full of random bytes that we continually cat to /dev/null.
> This fills the page cache as the file is read. Meanwhile we trigger
> the balloon to inflate, with a target size of 53 GB. This setup causes
> the balloon inflation to pressure the page cache as the page cache is
> also trying to grow. Afterwards we shrink the balloon back to zero (so
> total deflate = total inflate).
>
> Without patch (kernel 4.19.0-5):
> Inflation never reaches the target until we stop the "cat file >
> /dev/null" process. Total inflation time was 542 seconds. The longest
> period that made no net forward progress was 315 seconds (see attached
> graph).
> Result of "grep balloon /proc/vmstat" after the test:
> balloon_inflate 154828377
> balloon_deflate 154828377
>
> With patch (kernel 5.6.0-rc4+):
> Total inflation duration was 63 seconds. No deflate-queue activity
> occurs when pressuring the page-cache.
> Result of "grep balloon /proc/vmstat" after the test:
> balloon_inflate 12968539
> balloon_deflate 12968539
>
> Conclusion: This patch fixes the issue. In the test it reduced
> inflate/deflate activity by 12x, and reduced inflation time by 8.6x.
> But more importantly, if we hadn't killed the "grep balloon
> /proc/vmstat" process then, without the patch, the inflation process
> would never reach the target.
>
> Attached is a png of a graph showing the problematic behavior without
> this patch. It shows deflate-queue activity increasing linearly while
> balloon size stays constant over the course of more than 8 minutes of
> the test.
Thanks a lot for the extended test!
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2020-03-09 9:03 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-05 16:33 [PATCH v1 0/3] virtio-balloon: Fixes + switch back to OOM handler David Hildenbrand
2020-02-05 16:34 ` [PATCH v1 1/3] virtio-balloon: Fix memory leak when unloading while hinting is in progress David Hildenbrand
2020-02-06 8:36 ` Michael S. Tsirkin
2020-02-05 16:34 ` [PATCH v1 2/3] virtio_balloon: Fix memory leaks on errors in virtballoon_probe() David Hildenbrand
2020-02-06 8:36 ` Michael S. Tsirkin
2020-02-05 16:34 ` [PATCH v1 3/3] virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM David Hildenbrand
2020-02-05 22:37 ` Tyler Sanderson
2020-02-05 22:52 ` David Hildenbrand
2020-02-05 23:06 ` Tyler Sanderson
2020-02-06 7:40 ` Michael S. Tsirkin
2020-02-06 8:42 ` David Hildenbrand
2020-02-06 8:57 ` Michael S. Tsirkin
2020-02-06 9:05 ` David Hildenbrand
2020-02-06 9:09 ` Michael S. Tsirkin
2020-02-06 8:57 ` Wang, Wei W
2020-02-06 9:11 ` Michael S. Tsirkin
2020-02-06 9:12 ` Michael S. Tsirkin
2020-02-06 9:21 ` David Hildenbrand
2020-02-14 9:51 ` David Hildenbrand
2020-02-14 13:31 ` Wang, Wei W
2020-02-16 9:47 ` Michael S. Tsirkin
2020-02-21 3:29 ` Tyler Sanderson
2020-03-08 4:47 ` Tyler Sanderson
2020-03-09 9:03 ` David Hildenbrand [this message]
2020-03-09 10:14 ` Michael S. Tsirkin
2020-03-09 10:59 ` David Hildenbrand
2020-03-09 10:24 ` Michael S. Tsirkin
2020-02-14 14:06 ` Michal Hocko
2020-02-14 14:18 ` David Hildenbrand
2020-02-14 20:48 ` Tyler Sanderson
2020-02-14 21:17 ` David Hildenbrand
2020-02-16 9:46 ` Michael S. Tsirkin
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