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authorChris Metcalf <cmetcalf@ezchip.com>2015-07-10 15:37:25 -0400
committerFrederic Weisbecker <fweisbec@gmail.com>2015-07-29 15:44:59 +0200
commit03f6199a359e460714b6bd08c10b566760f150a6 (patch)
tree71adc3d1afe58a51f80df84152b969d4a6d36df1
parent2019e8a3024bd8fcadd57891a88c838849216a5f (diff)
nohz: Prevent tilegx network driver interrupts
Normally the tilegx networking shim sends irqs to all the cores to distribute the load of processing incoming-packet interrupts, so that you can get to multiple Gb's of traffic inbound. However, in nohz_full mode we don't want to interrupt the nohz_full cores by default, so we limit the set of cores we use to only the online housekeeping cores. To make client code easier to read, we introduce a new nohz_full accessor, housekeeping_cpumask(), which returns a pointer to the housekeeping_mask if nohz_full is enabled, and otherwise returns the cpu_possible_mask. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
-rw-r--r--drivers/net/ethernet/tile/tilegx.c4
-rw-r--r--include/linux/tick.h9
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c
index a3f7610002aa..0a15acc075b3 100644
--- a/drivers/net/ethernet/tile/tilegx.c
+++ b/drivers/net/ethernet/tile/tilegx.c
@@ -40,6 +40,7 @@
#include <linux/tcp.h>
#include <linux/net_tstamp.h>
#include <linux/ptp_clock_kernel.h>
+#include <linux/tick.h>
#include <asm/checksum.h>
#include <asm/homecache.h>
@@ -2273,7 +2274,8 @@ static int __init tile_net_init_module(void)
tile_net_dev_init(name, mac);
if (!network_cpus_init())
- network_cpus_map = *cpu_online_mask;
+ cpumask_and(&network_cpus_map, housekeeping_cpumask(),
+ cpu_online_mask);
return 0;
}
diff --git a/include/linux/tick.h b/include/linux/tick.h
index edbfc9a5293e..1ca93f2de6f5 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -163,6 +163,15 @@ static inline void tick_nohz_full_kick_all(void) { }
static inline void __tick_nohz_task_switch(struct task_struct *tsk) { }
#endif
+static inline const struct cpumask *housekeeping_cpumask(void)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ if (tick_nohz_full_enabled())
+ return housekeeping_mask;
+#endif
+ return cpu_possible_mask;
+}
+
static inline bool is_housekeeping_cpu(int cpu)
{
#ifdef CONFIG_NO_HZ_FULL