search for: invalidate_range

...S. Tsirkin wrote: > > > On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > > > > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > > > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > > > > + .invalidate_range = vhost_invalidate_range, > > > > > +}; > > > > > + > > > > > void vhost_dev_init(struct vhost_dev *dev, > > > > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > > > > { > > > > I also won...

...S. Tsirkin wrote: > > > On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > > > > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > > > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > > > > + .invalidate_range = vhost_invalidate_range, > > > > > +}; > > > > > + > > > > > void vhost_dev_init(struct vhost_dev *dev, > > > > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > > > > { > > > > I also won...

On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > + .invalidate_range = vhost_invalidate_range, > +}; > + > void vhost_dev_init(struct vhost_dev *dev, > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > { I also wonder here: when page is write protected then it does not look like .invalidate_range is invoked. E.g. mm/ksm.c calls mmu_...

On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > + .invalidate_range = vhost_invalidate_range, > +}; > + > void vhost_dev_init(struct vhost_dev *dev, > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > { I also wonder here: when page is write protected then it does not look like .invalidate_range is invoked. E.g. mm/ksm.c calls mmu_...

...ar 07, 2019 at 12:56:45PM -0500, Michael S. Tsirkin wrote: > On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > > + .invalidate_range = vhost_invalidate_range, > > > +}; > > > + > > > void vhost_dev_init(struct vhost_dev *dev, > > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > > { > > > > I also wonder here: when page is write protected then > &gt...

...ar 07, 2019 at 12:56:45PM -0500, Michael S. Tsirkin wrote: > On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > > + .invalidate_range = vhost_invalidate_range, > > > +}; > > > + > > > void vhost_dev_init(struct vhost_dev *dev, > > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > > { > > > > I also wonder here: when page is write protected then > &gt...

...Tsirkin wrote: >>>> On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: >>>>> On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: >>>>>> +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { >>>>>> + .invalidate_range = vhost_invalidate_range, >>>>>> +}; >>>>>> + >>>>>> void vhost_dev_init(struct vhost_dev *dev, >>>>>> struct vhost_virtqueue **vqs, int nvqs, int iov_limit) >>>>>> { >>>>> I also...

...ar 07, 2019 at 12:56:45PM -0500, Michael S. Tsirkin wrote: > On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > > + .invalidate_range = vhost_invalidate_range, > > > +}; > > > + > > > void vhost_dev_init(struct vhost_dev *dev, > > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > > { > > > > I also wonder here: when page is write protected then > &gt...

...ar 07, 2019 at 12:56:45PM -0500, Michael S. Tsirkin wrote: > On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > > + .invalidate_range = vhost_invalidate_range, > > > +}; > > > + > > > void vhost_dev_init(struct vhost_dev *dev, > > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > > { > > > > I also wonder here: when page is write protected then > &gt...

On 2019/3/8 ??5:27, Andrea Arcangeli wrote: > Hello Jerome, > > On Thu, Mar 07, 2019 at 03:17:22PM -0500, Jerome Glisse wrote: >> So for the above the easiest thing is to call set_page_dirty() from >> the mmu notifier callback. It is always safe to use the non locking >> variant from such callback. Well it is safe only if the page was >> map with write permission

On 2019/3/8 ??5:27, Andrea Arcangeli wrote: > Hello Jerome, > > On Thu, Mar 07, 2019 at 03:17:22PM -0500, Jerome Glisse wrote: >> So for the above the easiest thing is to call set_page_dirty() from >> the mmu notifier callback. It is always safe to use the non locking >> variant from such callback. Well it is safe only if the page was >> map with write permission

...S. Tsirkin wrote: > > > On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > > > > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > > > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > > > > + .invalidate_range = vhost_invalidate_range, > > > > > +}; > > > > > + > > > > > void vhost_dev_init(struct vhost_dev *dev, > > > > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > > > > { > > > > I also won...

...at 12:56:45PM -0500, Michael S. Tsirkin wrote: >> On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: >>> On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: >>>> +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { >>>> + .invalidate_range = vhost_invalidate_range, >>>> +}; >>>> + >>>> void vhost_dev_init(struct vhost_dev *dev, >>>> struct vhost_virtqueue **vqs, int nvqs, int iov_limit) >>>> { >>> I also wonder here: when page is write protected then &gt...

...ty after a round of virtqueue processing when we're sure vhost wrote > something there. Thanks for the clarification. So we need to convert it to set_page_dirty and move it to the mmu notifier invalidate but in those cases where gup_fast was called with write=1 (1 out of 3). If using ->invalidate_range the page pin also must be removed immediately after get_user_pages returns (not ok to hold the pin in vmap until ->invalidate_range is called) to avoid false positive gup pin checks in things like KSM, or the pin must be released in invalidate_range_start (which is called before the pin checks)....

...at 12:56:45PM -0500, Michael S. Tsirkin wrote: >> On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: >>> On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: >>>> +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { >>>> + .invalidate_range = vhost_invalidate_range, >>>> +}; >>>> + >>>> void vhost_dev_init(struct vhost_dev *dev, >>>> struct vhost_virtqueue **vqs, int nvqs, int iov_limit) >>>> { >>> I also wonder here: when page is write protected then &gt...

On Thu, Mar 07, 2019 at 10:47:22AM -0500, Michael S. Tsirkin wrote: > On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > > + .invalidate_range = vhost_invalidate_range, > > +}; > > + > > void vhost_dev_init(struct vhost_dev *dev, > > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > > { > > I also wonder here: when page is write protected then > it does not look like .invalidate_rang...

...e overheads by accessing them > through kernel virtual address by vmap(). To make the pages can be > migrated, instead of pinning them through GUP, we use MMU notifiers to > invalidate vmaps and re-establish vmaps during each round of metadata > prefetching if necessary. It looks to me .invalidate_range() is > sufficient for catching this since we don't need extra TLB flush. For > devices that doesn't use metadata prefetching, the memory accessors > fallback to normal copy_user() implementation gracefully. The > invalidation was synchronized with datapath through vq mutex, and...

...e overheads by accessing them > through kernel virtual address by vmap(). To make the pages can be > migrated, instead of pinning them through GUP, we use MMU notifiers to > invalidate vmaps and re-establish vmaps during each round of metadata > prefetching if necessary. It looks to me .invalidate_range() is > sufficient for catching this since we don't need extra TLB flush. For > devices that doesn't use metadata prefetching, the memory accessors > fallback to normal copy_user() implementation gracefully. The > invalidation was synchronized with datapath through vq mutex, and...

...n v1 sorry. I think what you mean is already done? struct mmu_range_notifier_ops { bool (*invalidate)(struct mmu_range_notifier *mrn, const struct mmu_notifier_range *range, unsigned long cur_seq); > No it is always odd, you must call mmu_range_set_seq() only from the > op->invalidate_range() callback at which point the seq is odd. As well > when mrn is added and its seq first set it is set to an odd value > always. Maybe the comment, should read: > > * mrn->invalidate_seq is always, yes always, set to an odd value. This ensures > > To stress that it is not an...

...h overheads like checks, spec barriers or even hardware feature toggling. This is done through setup kernel address through vmap() and resigter MMU notifier for invalidation. Test shows about 24% improvement on TX PPS. TCP_STREAM doesn't see obvious improvement. Thanks Changes from V4: - use invalidate_range() instead of invalidate_range_start() - track dirty pages Changes from V3: - don't try to use vmap for file backed pages - rebase to master Changes from V2: - fix buggy range overlapping check - tear down MMU notifier during vhost ioctl to make sure invalidation request can read metadata user...