Hi, Marvin
On 03/16, Marvin Liu wrote:
>If Tx zero copy enabled, gpa to hpa mapping table is updated one by
>one. This will harm performance when guest memory backend using 2M
>hugepages. Now add cached mapping table which will sorted by using
>sequence. Address translation will first check cached mapping table,
>now performance is back.
>
>Signed-off-by: Marvin Liu <yong....@intel.com>
>
>diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
>index 2087d1400..de2c09e7e 100644
>--- a/lib/librte_vhost/vhost.h
>+++ b/lib/librte_vhost/vhost.h
>@@ -368,7 +368,9 @@ struct virtio_net {
> struct vhost_device_ops const *notify_ops;
>
> uint32_t nr_guest_pages;
>+ uint32_t nr_cached;
What about naming it nr_cached_guest_pages to make it more self-explanatory
as nr_cached is too generic?
> uint32_t max_guest_pages;
>+ struct guest_page *cached_guest_pages;
> struct guest_page *guest_pages;
>
> int slave_req_fd;
>@@ -554,11 +556,23 @@ gpa_to_hpa(struct virtio_net *dev, uint64_t gpa,
>uint64_t size)
> uint32_t i;
> struct guest_page *page;
>
>+ for (i = 0; i < dev->nr_cached; i++) {
>+ page = &dev->cached_guest_pages[i];
>+ if (gpa >= page->guest_phys_addr &&
>+ gpa + size < page->guest_phys_addr + page->size) {
>+ return gpa - page->guest_phys_addr +
>+ page->host_phys_addr;
>+ }
>+ }
>+
> for (i = 0; i < dev->nr_guest_pages; i++) {
> page = &dev->guest_pages[i];
>
> if (gpa >= page->guest_phys_addr &&
> gpa + size < page->guest_phys_addr + page->size) {
>+ rte_memcpy(&dev->cached_guest_pages[dev->nr_cached],
>+ page, sizeof(struct guest_page));
>+ dev->nr_cached++;
> return gpa - page->guest_phys_addr +
> page->host_phys_addr;
> }
>diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
>index bd1be0104..573e99066 100644
>--- a/lib/librte_vhost/vhost_user.c
>+++ b/lib/librte_vhost/vhost_user.c
>@@ -192,7 +192,9 @@ vhost_backend_cleanup(struct virtio_net *dev)
> }
>
> free(dev->guest_pages);
>+ free(dev->cached_guest_pages);
> dev->guest_pages = NULL;
>+ dev->cached_guest_pages = NULL;
>
> if (dev->log_addr) {
> munmap((void *)(uintptr_t)dev->log_addr, dev->log_size);
>@@ -905,7 +907,10 @@ add_one_guest_page(struct virtio_net *dev, uint64_t
>guest_phys_addr,
> old_pages = dev->guest_pages;
> dev->guest_pages = realloc(dev->guest_pages,
> dev->max_guest_pages * sizeof(*page));
>- if (!dev->guest_pages) {
>+ dev->cached_guest_pages = realloc(dev->cached_guest_pages,
>+ dev->max_guest_pages * sizeof(*page));
>+ dev->nr_cached = 0;
>+ if (!dev->guest_pages || !dev->cached_guest_pages) {
Better to compare pointer to NULL according to DPDK's coding style.
> VHOST_LOG_CONFIG(ERR, "cannot realloc guest_pages\n");
> free(old_pages);
> return -1;
>@@ -1075,6 +1080,18 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
>struct VhostUserMsg *msg,
> }
> }
>
Do we need initialize dev->nr_cached to 0 explicitly here?
>+ if (!dev->cached_guest_pages) {
>+ dev->cached_guest_pages = malloc(dev->max_guest_pages *
>+ sizeof(struct guest_page));
I'm wondering why use malloc/realloc/free for cached_guest_pages instead of DPDK
memory allocator APIs, I can see current code uses malloc/realloc/free for
guest_pages,
Is there any history reason I don't know?
Thanks,
Xiaolong
>+ if (dev->cached_guest_pages == NULL) {
>+ VHOST_LOG_CONFIG(ERR,
>+ "(%d) failed to allocate memory "
>+ "for dev->cached_guest_pages\n",
>+ dev->vid);
>+ return RTE_VHOST_MSG_RESULT_ERR;
>+ }
>+ }
>+
> dev->mem = rte_zmalloc("vhost-mem-table", sizeof(struct
> rte_vhost_memory) +
> sizeof(struct rte_vhost_mem_region) * memory->nregions, 0);
> if (dev->mem == NULL) {
>--
>2.17.1
>
