From aa6ef27ea906e74bd23d14f43f095c012469d9c7 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <bhutchings@solarflare.com>
Date: Fri, 18 Jul 2008 19:03:10 +0100
Subject: [PATCH] sfc: Create one RX queue and interrupt per CPU package by
default
Using multiple cores in the same package to handle received traffic
does not appear to provide a performance benefit. Therefore use CPU
topology information to count CPU packages and use that as the default
number of RX queues and interrupts. We rely on interrupt balancing to
spread the interrupts across packages.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
drivers/net/sfc/efx.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 7b2a818662324..45c72eebb3a7e 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -19,6 +19,7 @@
#include <linux/in.h>
#include <linux/crc32.h>
#include <linux/ethtool.h>
+#include <linux/topology.h>
#include "net_driver.h"
#include "gmii.h"
#include "ethtool.h"
@@ -832,7 +833,23 @@ static void efx_probe_interrupts(struct efx_nic *efx)
if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
BUG_ON(!pci_find_capability(efx->pci_dev, PCI_CAP_ID_MSIX));
- efx->rss_queues = rss_cpus ? rss_cpus : num_online_cpus();
+ if (rss_cpus == 0) {
+ cpumask_t core_mask;
+ int cpu;
+
+ cpus_clear(core_mask);
+ efx->rss_queues = 0;
+ for_each_online_cpu(cpu) {
+ if (!cpu_isset(cpu, core_mask)) {
+ ++efx->rss_queues;
+ cpus_or(core_mask, core_mask,
+ topology_core_siblings(cpu));
+ }
+ }
+ } else {
+ efx->rss_queues = rss_cpus;
+ }
+
efx->rss_queues = min(efx->rss_queues, max_channel + 1);
efx->rss_queues = min(efx->rss_queues, EFX_MAX_CHANNELS);
--
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