Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Tuesday, December 22, 2020 9:57 PM
> To: dev@dpdk.org; Xia, Chenbo <chenbo....@intel.com>; amore...@redhat.com
> Cc: Maxime Coquelin <maxime.coque...@redhat.com>
> Subject: [PATCH 3/3] vhost: optimize vhost virtqueue struct
>
> This patch moves vhost_virtuqueue struct fields in order
s/virtuqueue/virtqueue
> to both optimize packing and move hot fields on the first
> cachelines.
'move hot fields to the first cacheline'? :)
>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> ---
> lib/librte_vhost/vhost.h | 52 +++++++++++++++++++++-------------------
> 1 file changed, 27 insertions(+), 25 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index e2f14034b4..ce76330d15 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -133,7 +133,7 @@ struct vhost_virtqueue {
> struct vring_used *used;
> struct vring_packed_desc_event *device_event;
> };
> - uint32_t size;
> + uint16_t size;
>
> uint16_t last_avail_idx;
> uint16_t last_used_idx;
> @@ -143,29 +143,12 @@ struct vhost_virtqueue {
> #define VIRTIO_INVALID_EVENTFD (-1)
> #define VIRTIO_UNINITIALIZED_EVENTFD (-2)
>
> - int enabled;
> - int access_ok;
> - int ready;
> - int notif_enable;
> -#define VIRTIO_UNINITIALIZED_NOTIF (-1)
> + bool enabled;
> + bool access_ok;
> + bool ready;
>
> rte_spinlock_t access_lock;
>
> - /* Used to notify the guest (trigger interrupt) */
> - int callfd;
> - /* Currently unused as polling mode is enabled */
> - int kickfd;
> -
> - /* Physical address of used ring, for logging */
> - uint64_t log_guest_addr;
> -
> - /* inflight share memory info */
> - union {
> - struct rte_vhost_inflight_info_split *inflight_split;
> - struct rte_vhost_inflight_info_packed *inflight_packed;
> - };
> - struct rte_vhost_resubmit_info *resubmit_inflight;
> - uint64_t global_counter;
>
> union {
> struct vring_used_elem *shadow_used_split;
> @@ -176,22 +159,36 @@ struct vhost_virtqueue {
> uint16_t shadow_aligned_idx;
> /* Record packed ring first dequeue desc index */
> uint16_t shadow_last_used_idx;
> - struct vhost_vring_addr ring_addrs;
>
> - struct batch_copy_elem *batch_copy_elems;
> uint16_t batch_copy_nb_elems;
> + struct batch_copy_elem *batch_copy_elems;
> bool used_wrap_counter;
> bool avail_wrap_counter;
>
> - struct log_cache_entry *log_cache;
> + /* Physical address of used ring, for logging */
> uint16_t log_cache_nb_elem;
> + uint64_t log_guest_addr;
Looks better to align 'log_cache_nb_elem' with 'log_guest_addr'?
Thanks,
Chenbo
> + struct log_cache_entry *log_cache;
>
> rte_rwlock_t iotlb_lock;
> rte_rwlock_t iotlb_pending_lock;
> struct rte_mempool *iotlb_pool;
> TAILQ_HEAD(, vhost_iotlb_entry) iotlb_list;
> - int iotlb_cache_nr;
> TAILQ_HEAD(, vhost_iotlb_entry) iotlb_pending_list;
> + int iotlb_cache_nr;
> +
> + /* Used to notify the guest (trigger interrupt) */
> + int callfd;
> + /* Currently unused as polling mode is enabled */
> + int kickfd;
> +
> + /* inflight share memory info */
> + union {
> + struct rte_vhost_inflight_info_split *inflight_split;
> + struct rte_vhost_inflight_info_packed *inflight_packed;
> + };
> + struct rte_vhost_resubmit_info *resubmit_inflight;
> + uint64_t global_counter;
>
> /* operation callbacks for async dma */
> struct rte_vhost_async_channel_ops async_ops;
> @@ -210,6 +207,11 @@ struct vhost_virtqueue {
> bool async_inorder;
> bool async_registered;
> uint16_t async_threshold;
> +
> + int notif_enable;
> +#define VIRTIO_UNINITIALIZED_NOTIF (-1)
> +
> + struct vhost_vring_addr ring_addrs;
> } __rte_cache_aligned;
>
> /* Virtio device status as per Virtio specification */
> --
> 2.29.2
