Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-06 Thread Tyler Sanderson via Virtualization
On Sun, Oct 6, 2019 at 4:48 AM Michael S. Tsirkin wrote: > On Sun, Oct 06, 2019 at 10:30:40AM +0200, David Hildenbrand wrote: > > Please note the "use outside of a testing or debugging environment is > > not recommended". Usually you want a "soft" version of this, e.g., via > > the OOM handler

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-06 Thread Michael S. Tsirkin
On Sun, Oct 06, 2019 at 10:30:40AM +0200, David Hildenbrand wrote: > Please note the "use outside of a testing or debugging environment is > not recommended". Usually you want a "soft" version of this, e.g., via > the OOM handler (so only drop parts of the cache, not all). Right. We'll need

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-06 Thread David Hildenbrand
On 04.10.19 21:03, Tyler Sanderson wrote: > I think DEFLATE_ON_OOM makes sense conceptually, it's just that the > implementation doesn't play well with the rest of memory management > under memory pressure. > It could probably be fixed with enough effort, but IMO free page hinting > gets 90% of

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-05 Thread Michael S. Tsirkin
On Fri, Oct 04, 2019 at 12:03:43PM -0700, Tyler Sanderson wrote: > I think DEFLATE_ON_OOM makes sense conceptually, it's just that the > implementation doesn't play well with the rest of memory management under > memory pressure. > It could probably be fixed with enough effort, but IMO free page

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-04 Thread David Hildenbrand
On 04.10.19 10:35, Michael S. Tsirkin wrote: > On Fri, Oct 04, 2019 at 10:06:03AM +0200, David Hildenbrand wrote: >> On 04.10.19 01:15, Tyler Sanderson wrote: >>> I was mistaken, the problem with overcommit accounting is not fixed by >>> the change to shrinker interface. >>> This means that large

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-04 Thread Michael S. Tsirkin
On Fri, Oct 04, 2019 at 10:06:03AM +0200, David Hildenbrand wrote: > On 04.10.19 01:15, Tyler Sanderson wrote: > > I was mistaken, the problem with overcommit accounting is not fixed by > > the change to shrinker interface. > > This means that large allocations are stopped even if they could

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-04 Thread David Hildenbrand
On 04.10.19 01:15, Tyler Sanderson wrote: > I was mistaken, the problem with overcommit accounting is not fixed by > the change to shrinker interface. > This means that large allocations are stopped even if they could succeed > by deflating the balloon. Please note that some people use the

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-10-03 Thread Michael S. Tsirkin
On Thu, Oct 03, 2019 at 11:27:46AM -0700, Tyler Sanderson wrote: > Sorry for the slow reply, I did some verification on my end. See responses > inline. > > On Mon, Sep 16, 2019 at 12:26 AM David Hildenbrand wrote: > > On 16.09.19 03:41, Wei Wang wrote: > > On 09/14/2019 02:36 AM, Tyler

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-09-16 Thread David Hildenbrand
On 16.09.19 03:41, Wei Wang wrote: > On 09/14/2019 02:36 AM, Tyler Sanderson wrote: >> Hello, I'm curious about the intent of VIRTIO_BALLOON_F_FREE_PAGE_HINT >> (commit >> ).

Re: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2019-09-15 Thread Wei Wang
On 09/14/2019 02:36 AM, Tyler Sanderson wrote: Hello, I'm curious about the intent of VIRTIO_BALLOON_F_FREE_PAGE_HINT (commit ). My understanding is that this mechanism