similar to: [PATCH] virtio-balloon: do not call blocking ops when !TASK_RUNNING

On Thu, Feb 26, 2015 at 06:08:49PM +0100, Peter Zijlstra wrote: > On Thu, Feb 26, 2015 at 09:30:31AM +0100, Michael S. Tsirkin wrote: > > On Thu, Feb 26, 2015 at 11:50:42AM +1030, Rusty Russell wrote: > > > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > > > Hi all, > > > > > > > > with the recent kernel 3.19, I get a kernel

On Thu, Feb 26, 2015 at 06:08:49PM +0100, Peter Zijlstra wrote: > On Thu, Feb 26, 2015 at 09:30:31AM +0100, Michael S. Tsirkin wrote: > > On Thu, Feb 26, 2015 at 11:50:42AM +1030, Rusty Russell wrote: > > > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > > > Hi all, > > > > > > > > with the recent kernel 3.19, I get a kernel

virtio balloon has this code: wait_event_interruptible(vb->config_change, (diff = towards_target(vb)) != 0 || vb->need_stats_update || kthread_should_stop() || freezing(current)); Which is a problem because towards_target() call might block after

virtio balloon has this code: wait_event_interruptible(vb->config_change, (diff = towards_target(vb)) != 0 || vb->need_stats_update || kthread_should_stop() || freezing(current)); Which is a problem because towards_target() call might block after

On Thu, Feb 26, 2015 at 11:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither

On Thu, Feb 26, 2015 at 11:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither

On Wed, 25 Feb 2015 16:11:27 +0100 Cornelia Huck <cornelia.huck at de.ibm.com> wrote: > On Wed, 25 Feb 2015 15:36:02 +0100 > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > virtio balloon has this code: > > wait_event_interruptible(vb->config_change, > > (diff = towards_target(vb)) != 0 > >

On Wed, 25 Feb 2015 16:11:27 +0100 Cornelia Huck <cornelia.huck at de.ibm.com> wrote: > On Wed, 25 Feb 2015 15:36:02 +0100 > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > virtio balloon has this code: > > wait_event_interruptible(vb->config_change, > > (diff = towards_target(vb)) != 0 > >

On Wed, 25 Feb 2015 15:14:36 +0100 "Michael S. Tsirkin" <mst at redhat.com> wrote: > virtio balloon has this code: > wait_event_interruptible(vb->config_change, > (diff = towards_target(vb)) != 0 > || vb->need_stats_update > || kthread_should_stop() >

On Wed, 25 Feb 2015 15:14:36 +0100 "Michael S. Tsirkin" <mst at redhat.com> wrote: > virtio balloon has this code: > wait_event_interruptible(vb->config_change, > (diff = towards_target(vb)) != 0 > || vb->need_stats_update > || kthread_should_stop() >

It has been long since I have sent v3 of the balloon conversion from a kthread to a workqueue. I have gained some more experience with the APIs in the meantime. I hope that you would like the outcome. I have added one more patch that fixes a separate problem with restoring the balloon after the system freeze. I have found this when testing the conversion. Changes against v3: + rebased on

It has been long since I have sent v3 of the balloon conversion from a kthread to a workqueue. I have gained some more experience with the APIs in the meantime. I hope that you would like the outcome. I have added one more patch that fixes a separate problem with restoring the balloon after the system freeze. I have found this when testing the conversion. Changes against v3: + rebased on

The previous version did not prevent updating the balloon when it was being removed. There was an idea to update the stats in a separate work and cancel it after the config reset. But this does not seem to work. The code for updating the stats communicates with the host. IMHO, it should not run after the reset (flushing buffers). Therefore I decided to use a boolean value and a spin lock (inspired

The previous version did not prevent updating the balloon when it was being removed. There was an idea to update the stats in a separate work and cancel it after the config reset. But this does not seem to work. The code for updating the stats communicates with the host. IMHO, it should not run after the reset (flushing buffers). Therefore I decided to use a boolean value and a spin lock (inspired

Hi all, with the recent kernel 3.19, I get a kernel warning when I start my KVM guest on s390 with virtio balloon enabled: [ 0.839687] do not call blocking ops when !TASK_RUNNING; state=1 set at [<0000000000174a1e>] prepare_to_wait_event+0x7e/0x108 [ 0.839694] ------------[ cut here ]------------ [ 0.839697] WARNING: at kernel/sched/core.c:7326 [ 0.839698]

Hi all, with the recent kernel 3.19, I get a kernel warning when I start my KVM guest on s390 with virtio balloon enabled: [ 0.839687] do not call blocking ops when !TASK_RUNNING; state=1 set at [<0000000000174a1e>] prepare_to_wait_event+0x7e/0x108 [ 0.839694] ------------[ cut here ]------------ [ 0.839697] WARNING: at kernel/sched/core.c:7326 [ 0.839698]

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 Wed, 25 Feb 2015 15:36:02 +0100 "Michael S. Tsirkin" <mst at redhat.com> wrote: > virtio balloon has this code: > wait_event_interruptible(vb->config_change, > (diff = towards_target(vb)) != 0 > || vb->need_stats_update > || kthread_should_stop() >

On Wed, 25 Feb 2015 15:36:02 +0100 "Michael S. Tsirkin" <mst at redhat.com> wrote: > virtio balloon has this code: > wait_event_interruptible(vb->config_change, > (diff = towards_target(vb)) != 0 > || vb->need_stats_update > || kthread_should_stop() >