Messages in this thread | | | From | Xie Yongji <> | Subject | [PATCH v3 00/11] VDUSE: Improve performance | Date | Tue, 28 Feb 2023 17:40:59 +0800 |
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Hi all,
This series introduces some ways to improve VDUSE performance.
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
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