similar to: Balloon pressuring page cache

On 05.02.20 08:35, Nadav Amit wrote: >> On Feb 3, 2020, at 2:50 PM, Nadav Amit <namit at vmware.com> wrote: >> >>> On Feb 3, 2020, at 8:34 AM, David Hildenbrand <david at redhat.com> wrote: >>> >>> On 03.02.20 17:18, Alexander Duyck wrote: >>>> On Mon, 2020-02-03 at 08:11 -0500, Michael S. Tsirkin wrote: >>>>> On Thu,

On Mon, Feb 03, 2020 at 05:34:20PM +0100, David Hildenbrand wrote: > On 03.02.20 17:18, Alexander Duyck wrote: > > On Mon, 2020-02-03 at 08:11 -0500, Michael S. Tsirkin wrote: > >> On Thu, Jan 30, 2020 at 11:59:46AM -0800, Tyler Sanderson wrote: > >>> > >>> On Thu, Jan 30, 2020 at 7:31 AM Wang, Wei W <wei.w.wang at intel.com> wrote: > >>>

> On Feb 3, 2020, at 8:34 AM, David Hildenbrand <david at redhat.com> wrote: > > On 03.02.20 17:18, Alexander Duyck wrote: >> On Mon, 2020-02-03 at 08:11 -0500, Michael S. Tsirkin wrote: >>> On Thu, Jan 30, 2020 at 11:59:46AM -0800, Tyler Sanderson wrote: >>>> On Thu, Jan 30, 2020 at 7:31 AM Wang, Wei W <wei.w.wang at intel.com> wrote:

On Wed, Feb 05, 2020 at 09:19:58AM +0100, David Hildenbrand wrote: > On 05.02.20 08:35, Nadav Amit wrote: > >> On Feb 3, 2020, at 2:50 PM, Nadav Amit <namit at vmware.com> wrote: > >> > >>> On Feb 3, 2020, at 8:34 AM, David Hildenbrand <david at redhat.com> wrote: > >>> > >>> On 03.02.20 17:18, Alexander Duyck wrote: >

> On Feb 3, 2020, at 2:50 PM, Nadav Amit <namit at vmware.com> wrote: > >> On Feb 3, 2020, at 8:34 AM, David Hildenbrand <david at redhat.com> wrote: >> >> On 03.02.20 17:18, Alexander Duyck wrote: >>> On Mon, 2020-02-03 at 08:11 -0500, Michael S. Tsirkin wrote: >>>> On Thu, Jan 30, 2020 at 11:59:46AM -0800, Tyler Sanderson wrote:

> On Feb 3, 2020, at 2:50 PM, Nadav Amit <namit at vmware.com> wrote: > >> On Feb 3, 2020, at 8:34 AM, David Hildenbrand <david at redhat.com> wrote: >> >> On 03.02.20 17:18, Alexander Duyck wrote: >>> On Mon, 2020-02-03 at 08:11 -0500, Michael S. Tsirkin wrote: >>>> On Thu, Jan 30, 2020 at 11:59:46AM -0800, Tyler Sanderson wrote:

There were apparently good reasons for moving away from OOM notifier callback: https://lkml.org/lkml/2018/7/12/314 https://lkml.org/lkml/2018/8/2/322 In particular the OOM notifier is worse than the shrinker because: 1. It is last-resort, which means the system has already gone through heroics to prevent OOM. Those heroic reclaim efforts are expensive and impact application performance.

There were apparently good reasons for moving away from OOM notifier callback: https://lkml.org/lkml/2018/7/12/314 https://lkml.org/lkml/2018/8/2/322 In particular the OOM notifier is worse than the shrinker because: 1. It is last-resort, which means the system has already gone through heroics to prevent OOM. Those heroic reclaim efforts are expensive and impact application performance.

On 03.02.20 17:18, Alexander Duyck wrote: > On Mon, 2020-02-03 at 08:11 -0500, Michael S. Tsirkin wrote: >> On Thu, Jan 30, 2020 at 11:59:46AM -0800, Tyler Sanderson wrote: >>> >>> On Thu, Jan 30, 2020 at 7:31 AM Wang, Wei W <wei.w.wang at intel.com> wrote: >>> >>> On Thursday, January 30, 2020 11:03 PM, David Hildenbrand wrote: >>>

On 03.02.20 17:18, Alexander Duyck wrote: > On Mon, 2020-02-03 at 08:11 -0500, Michael S. Tsirkin wrote: >> On Thu, Jan 30, 2020 at 11:59:46AM -0800, Tyler Sanderson wrote: >>> >>> On Thu, Jan 30, 2020 at 7:31 AM Wang, Wei W <wei.w.wang at intel.com> wrote: >>> >>> On Thursday, January 30, 2020 11:03 PM, David Hildenbrand wrote: >>>

On Wed, 29 Jan 2020, Tyler Sanderson wrote: > > > A primary advantage of virtio balloon over other memory reclaim > > > mechanisms is that it can pressure the guest's page cache into shrinking. > > > > > > However, since the balloon driver changed to using the shrinker API > > > < > >

On Tue, 10 Mar 2020, David Hildenbrand wrote: > Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") > changed the behavior when deflation happens automatically. Instead of > deflating when called by the OOM handler, the shrinker is used. > > However, the balloon is not simply some other slab cache that should be > shrunk when under memory

On Tue, Mar 10, 2020 at 08:13:19PM +0100, David Hildenbrand wrote: > On 10.03.20 20:05, David Rientjes wrote: > > On Tue, 10 Mar 2020, David Hildenbrand wrote: > > > >> Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") > >> changed the behavior when deflation happens automatically. Instead of > >> deflating when called

Tested-by: Tyler Sanderson <tysand at 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

On 10.03.20 20:05, David Rientjes wrote: > On Tue, 10 Mar 2020, David Hildenbrand wrote: > >> Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") >> changed the behavior when deflation happens automatically. Instead of >> deflating when called by the OOM handler, the shrinker is used. >> >> However, the balloon is not simply

On 10.03.20 20:05, David Rientjes wrote: > On Tue, 10 Mar 2020, David Hildenbrand wrote: > >> Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") >> changed the behavior when deflation happens automatically. Instead of >> deflating when called by the OOM handler, the shrinker is used. >> >> However, the balloon is not simply

Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") changed the behavior when deflation happens automatically. Instead of deflating when called by the OOM handler, the shrinker is used. However, the balloon is not simply some other slab cache that should be shrunk when under memory pressure. The shrinker does not have a concept of priorities yet, so this behavior

From: David Hildenbrand <david at redhat.com> [ Upstream commit 5a6b4cc5b7a1892a8d7f63d6cbac6e0ae2a9d031 ] Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") changed the behavior when deflation happens automatically. Instead of deflating when called by the OOM handler, the shrinker is used. However, the balloon is not simply some slab cache that should be

From: David Hildenbrand <david at redhat.com> [ Upstream commit 5a6b4cc5b7a1892a8d7f63d6cbac6e0ae2a9d031 ] Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") changed the behavior when deflation happens automatically. Instead of deflating when called by the OOM handler, the shrinker is used. However, the balloon is not simply some slab cache that should be

On Tue, Mar 10, 2020 at 11:39:03AM +0100, David Hildenbrand wrote: > Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") > changed the behavior when deflation happens automatically. Instead of > deflating when called by the OOM handler, the shrinker is used. > > However, the balloon is not simply some other slab cache that should be > shrunk when