redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

virtio_net: Stripe queue affinities across cores. 

Always set the affinity hint, even if #cpu != #vq.

Handle the case where #cpu > #vq (including when #cpu % #vq != 0) and
when #vq > #cpu (including when #vq % #cpu != 0).

Signed-off-by: Caleb Raitto <caraitto@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jon Olson <jonolson@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Caleb Raitto 2018-08-09 17:28:40 -07:00 committed by David S. Miller
parent 19e226e8cc
commit 2ca653d607
1 changed files with 27 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/net/virtio_net.c
View File

@ -31,6 +31,7 @@
#include <linux/average.h>
#include <linux/filter.h>
#include <linux/netdevice.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <net/route.h>
#include <net/xdp.h>
@ -1888,30 +1889,41 @@ static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
static void virtnet_set_affinity(struct virtnet_info *vi)
{
int i;
int cpu;
cpumask_var_t mask;
int stragglers;
int group_size;
int i, j, cpu;
int num_cpu;
int stride;
/* In multiqueue mode, when the number of cpu is equal to the number of
* queue pairs, we let the queue pairs to be private to one cpu by
* setting the affinity hint to eliminate the contention.
*/
if (vi->curr_queue_pairs == 1 ||
vi->max_queue_pairs != num_online_cpus()) {
if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
virtnet_clean_affinity(vi, -1);
return;
}
i = 0;
for_each_online_cpu(cpu) {
const unsigned long *mask = cpumask_bits(cpumask_of(cpu));
num_cpu = num_online_cpus();
stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
stragglers = num_cpu >= vi->curr_queue_pairs ?
num_cpu % vi->curr_queue_pairs :
0;
cpu = cpumask_next(-1, cpu_online_mask);
virtqueue_set_affinity(vi->rq[i].vq, cpumask_of(cpu));
virtqueue_set_affinity(vi->sq[i].vq, cpumask_of(cpu));
__netif_set_xps_queue(vi->dev, mask, i, false);
i++;
for (i = 0; i < vi->curr_queue_pairs; i++) {
group_size = stride + (i < stragglers ? 1 : 0);
for (j = 0; j < group_size; j++) {
cpumask_set_cpu(cpu, mask);
cpu = cpumask_next_wrap(cpu, cpu_online_mask,
nr_cpu_ids, false);
}
virtqueue_set_affinity(vi->rq[i].vq, mask);
virtqueue_set_affinity(vi->sq[i].vq, mask);
__netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, false);
cpumask_clear(mask);
}
vi->affinity_hint_set = true;
free_cpumask_var(mask);
}
static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)