similar to: [PATCH] virtio_balloon: Notify guest only after deflating the balloon

The virtio balloon driver has a VIRTIO_BALLOON_F_MUST_TELL_HOST feature bit. Whenever the bit is set, we must always tell the host before we free pages back to the allocator. Without this we might free a page (and have another user touch it) while the hypervisor is unprepared for it. But, if the bit is _not_ set, we are under no obligation to reverse the order. Furthermore, all modern qemus

The virtio balloon driver has a VIRTIO_BALLOON_F_MUST_TELL_HOST feature bit. Whenever the bit is set, we must always tell the host before we free pages back to the allocator. Without this we might free a page (and have another user touch it) while the hypervisor is unprepared for it. But, if the bit is _not_ set, we are under no obligation to reverse the order. Furthermore, all modern qemus

Il 28/05/2013 15:32, Michael S. Tsirkin ha scritto: > At this point I am confused. I think there are two changes in your patch: > > 1. Handling of VIRTIO_F_GUEST_MUST_TELL_HOST > Is this functionally identical to what I proposed? > If yes, I am fine with either change being applied. Yes. > 2. New SILENT_DEFLATE feature > Since guest can get same functionality by not

On Wed, Feb 05, 2020 at 05:34:02PM +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 slab cache that should be > shrunk when under

On Wed, Feb 05, 2020 at 05:34:02PM +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 slab cache that should be > shrunk when under

Il 28/05/2013 16:29, Michael S. Tsirkin ha scritto: > On Tue, May 28, 2013 at 04:06:02PM +0200, Paolo Bonzini wrote: >> Il 28/05/2013 15:32, Michael S. Tsirkin ha scritto: >>> At this point I am confused. I think there are two changes in your patch: >>> >>> 1. Handling of VIRTIO_F_GUEST_MUST_TELL_HOST >>> Is this functionally identical to what I

On Thu, Feb 06, 2020 at 09:42:34AM +0100, David Hildenbrand wrote: > On 06.02.20 08:40, Michael S. Tsirkin wrote: > > On Wed, Feb 05, 2020 at 05:34:02PM +0100, David Hildenbrand wrote: > >> Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") > >> changed the behavior when deflation happens automatically. Instead of > >> deflating

On Thu, Feb 06, 2020 at 09:42:34AM +0100, David Hildenbrand wrote: > On 06.02.20 08:40, Michael S. Tsirkin wrote: > > On Wed, Feb 05, 2020 at 05:34:02PM +0100, David Hildenbrand wrote: > >> Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") > >> changed the behavior when deflation happens automatically. Instead of > >> deflating

Il 28/05/2013 17:09, Michael S. Tsirkin ha scritto: > On Tue, May 28, 2013 at 04:32:44PM +0200, Paolo Bonzini wrote: >> Il 28/05/2013 16:29, Michael S. Tsirkin ha scritto: >>> On Tue, May 28, 2013 at 04:06:02PM +0200, Paolo Bonzini wrote: >>>> Il 28/05/2013 15:32, Michael S. Tsirkin ha scritto: >>>>> At this point I am confused. I think there are two

Workqueues have clean and rich API for all basic operations. The code is usually easier and better readable. It can be easily tuned for the given purpose. In many cases, it allows to avoid an extra kernel thread. It helps to stop the growing number of them. Also there will be less thread-specific hacks all over the kernel code. It forces making the task selfcontained. There is no longer an

Workqueues have clean and rich API for all basic operations. The code is usually easier and better readable. It can be easily tuned for the given purpose. In many cases, it allows to avoid an extra kernel thread. It helps to stop the growing number of them. Also there will be less thread-specific hacks all over the kernel code. It forces making the task selfcontained. There is no longer an

On Tue, May 28, 2013 at 04:06:02PM +0200, Paolo Bonzini wrote: > Il 28/05/2013 15:32, Michael S. Tsirkin ha scritto: > > At this point I am confused. I think there are two changes in your patch: > > > > 1. Handling of VIRTIO_F_GUEST_MUST_TELL_HOST > > Is this functionally identical to what I proposed? > > If yes, I am fine with either change being applied. >

This series contains one cleanup and two bug fixes for the virtio balloon driver.

This series contains one cleanup and two bug fixes for the virtio balloon driver.

On Tue, May 28, 2013 at 04:32:44PM +0200, Paolo Bonzini wrote: > Il 28/05/2013 16:29, Michael S. Tsirkin ha scritto: > > On Tue, May 28, 2013 at 04:06:02PM +0200, Paolo Bonzini wrote: > >> Il 28/05/2013 15:32, Michael S. Tsirkin ha scritto: > >>> At this point I am confused. I think there are two changes in your patch: > >>> > >>> 1. Handling

On Tue, May 28, 2013 at 06:23:19PM +0200, Paolo Bonzini wrote: > Il 28/05/2013 17:09, Michael S. Tsirkin ha scritto: > > On Tue, May 28, 2013 at 04:32:44PM +0200, Paolo Bonzini wrote: > >> Il 28/05/2013 16:29, Michael S. Tsirkin ha scritto: > >>> On Tue, May 28, 2013 at 04:06:02PM +0200, Paolo Bonzini wrote: > >>>> Il 28/05/2013 15:32, Michael S.

On 06.02.20 08:40, Michael S. Tsirkin wrote: > On Wed, Feb 05, 2020 at 05:34:02PM +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

The implementation of the current virtio-balloon is not very efficient, Bellow is test result of time spends on inflating the balloon to 3GB of a 4GB idle guest: a. allocating pages (6.5%, 103ms) b. sending PFNs to host (68.3%, 787ms) c. address translation (6.1%, 96ms) d. madvise (19%, 300ms) It takes about 1577ms for the whole inflating process to complete. The test shows that the bottle neck

The implementation of the current virtio-balloon is not very efficient, Bellow is test result of time spends on inflating the balloon to 3GB of a 4GB idle guest: a. allocating pages (6.5%, 103ms) b. sending PFNs to host (68.3%, 787ms) c. address translation (6.1%, 96ms) d. madvise (19%, 300ms) It takes about 1577ms for the whole inflating process to complete. The test shows that the bottle neck

On Fri, Oct 21, 2016 at 02:24:37PM +0800, Liang Li wrote: > The implementation of the current virtio-balloon is not very > efficient, the time spends on different stages of inflating > the balloon to 7GB of a 8GB idle guest: > > a. allocating pages (6.5%) > b. sending PFNs to host (68.3%) > c. address translation (6.1%) > d. madvise (19%) > > It takes about 4126ms