On Tue, Feb 28, 2023 at 05:40:59PM +0800, Xie Yongji wrote: > Hi all, > > This series introduces some ways to improve VDUSE performance. Pls fix warnings reported by 0-day infra, dropping this for now. > Patch 1 ~ 6 bring current interrupt affinity spreading mechanism > to vduse device and make it possible for the virtio-blk driver > to build the blk-mq queues based on it. This would be useful to > mitigate the virtqueue lock contention in virtio-blk driver. In > our test, with those patches, we could get ~50% improvement (600k > iops -> 900k iops) when using per-cpu virtqueue. > > Patch 7 adds a sysfs interface for each vduse virtqueue to change > the affinity for IRQ callback. It would be helpful for performance > tuning when the affinity mask contains more than one CPU. > > Patch 8 ~ 9 associate an eventfd to the vdpa callback so that > we can signal it directly during irq injection without scheduling > an additional workqueue thread to do that. > > Patch 10, 11 add a sysfs interface to support specifying bounce > buffer size in virtio-vdpa case. The high throughput workloads > can benefit from it. And we can also use it to reduce the memory > overhead for small throughput workloads. > > Please review, thanks! > > V2 to V3: > - Rebased to newest kernel tree > - Export group_cpus_evenly() instead of irq_create_affinity_masks() [MST] > - Remove the sysfs for workqueue control [Jason] > - Associate an eventfd to the vdpa callback [Jason] > - Signal the eventfd directly in vhost-vdpa case [Jason] > - Use round-robin to spread IRQs between CPUs in the affinity mask [Jason] > - Handle the cpu hotplug case on IRQ injection [Jason] > - Remove effective IRQ affinity and balance mechanism for IRQ allocation > > V1 to V2: > - Export irq_create_affinity_masks() > - Add set/get_vq_affinity and set_irq_affinity callbacks in vDPA > framework > - Add automatic irq callback affinity support in VDUSE driver [Jason] > - Add more backgrounds information in commit log [Jason] > - Only support changing effective affinity when the value is a subset > of the IRQ callback affinity mask > > Xie Yongji (11): > lib/group_cpus: Export group_cpus_evenly() > vdpa: Add set/get_vq_affinity callbacks in vdpa_config_ops > vdpa: Add set_irq_affinity callback in vdpa_config_ops > vduse: Refactor allocation for vduse virtqueues > vduse: Support automatic irq callback affinity > vduse: Support set/get_vq_affinity callbacks > vduse: Add sysfs interface for irq callback affinity > vdpa: Add eventfd for the vdpa callback > vduse: Signal interrupt's eventfd directly in vhost-vdpa case > vduse: Delay iova domain creation > vduse: Support specifying bounce buffer size via sysfs > > drivers/vdpa/vdpa_user/vduse_dev.c | 490 +++++++++++++++++++++++++---- > drivers/vhost/vdpa.c | 2 + > drivers/virtio/virtio_vdpa.c | 33 ++ > include/linux/vdpa.h | 25 ++ > lib/group_cpus.c | 1 + > 5 files changed, 488 insertions(+), 63 deletions(-) > > -- > 2.20.1 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
