Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-12 Thread Alex Williamson
On Wed, 12 Apr 2017 12:13:43 +0800 Peter Xu wrote: > On Tue, Apr 11, 2017 at 12:50:11PM -0600, Alex Williamson wrote: > > On Tue, 11 Apr 2017 12:27:55 -0600 > > Alex Williamson wrote: > > > > > On Tue, 11 Apr 2017 19:03:14 +0800 > > > Peter Xu wrote: > > > > > > > On Thu, Apr 06, 2017 at

Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-11 Thread Peter Xu
On Tue, Apr 11, 2017 at 12:50:11PM -0600, Alex Williamson wrote: > On Tue, 11 Apr 2017 12:27:55 -0600 > Alex Williamson wrote: > > > On Tue, 11 Apr 2017 19:03:14 +0800 > > Peter Xu wrote: > > > > > On Thu, Apr 06, 2017 at 08:53:43AM -0600, Alex Williamson wrote: [...] > > > > -static void v

Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-11 Thread Alex Williamson
On Tue, 11 Apr 2017 12:27:55 -0600 Alex Williamson wrote: > On Tue, 11 Apr 2017 19:03:14 +0800 > Peter Xu wrote: > > > On Thu, Apr 06, 2017 at 08:53:43AM -0600, Alex Williamson wrote: > > > If the mmap_sem is contented then the vfio type1 IOMMU backend will > > > defer locked page accounting

Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-11 Thread Alex Williamson
On Tue, 11 Apr 2017 19:03:14 +0800 Peter Xu wrote: > On Thu, Apr 06, 2017 at 08:53:43AM -0600, Alex Williamson wrote: > > If the mmap_sem is contented then the vfio type1 IOMMU backend will > > defer locked page accounting updates to a workqueue task. This has > > a few problems and depending on

Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-11 Thread Peter Xu
On Thu, Apr 06, 2017 at 08:53:43AM -0600, Alex Williamson wrote: > If the mmap_sem is contented then the vfio type1 IOMMU backend will > defer locked page accounting updates to a workqueue task. This has > a few problems and depending on which side the user tries to play, > they might be over-pena

Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-06 Thread Alex Williamson
On Thu, 6 Apr 2017 11:05:31 -0600 Alex Williamson wrote: > On Thu, 6 Apr 2017 18:53:04 +0200 > Auger Eric wrote: > > > Hi Alex, > > > > On 06/04/2017 16:53, Alex Williamson wrote: > > > If the mmap_sem is contented then the vfio type1 IOMMU backend will > > > defer locked page accounting upd

Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-06 Thread Alex Williamson
On Thu, 6 Apr 2017 18:53:04 +0200 Auger Eric wrote: > Hi Alex, > > On 06/04/2017 16:53, Alex Williamson wrote: > > If the mmap_sem is contented then the vfio type1 IOMMU backend will > > defer locked page accounting updates to a workqueue task. This has > > a few problems and depending on which

Re: [PATCH v2] vfio/type1: Remove locked page accounting workqueue

2017-04-06 Thread Auger Eric
Hi Alex, On 06/04/2017 16:53, Alex Williamson wrote: > If the mmap_sem is contented then the vfio type1 IOMMU backend will > defer locked page accounting updates to a workqueue task. This has > a few problems and depending on which side the user tries to play, > they might be over-penalized for u