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authorLuke Browning <lukebr@linux.vnet.ibm.com>2008-04-28 14:32:34 +1000
committerJeremy Kerr <jk@ozlabs.org>2008-05-05 13:33:43 +1000
commit7a2142002f29a7b398c49da9bdec712dc57087c7 (patch)
treebd15498cbf76cabda2d42868ffc6936738d5c578
parent093c16bf9b107433643cbf0843ca7808df90823b (diff)
[POWERPC] spufs: try to route SPU interrupts to local node
Currently, we re-route SPU interrupts to the current cpu, which may be on a remote node. In the case of time slicing, all spu interrupts will end up routed to the same cpu, where the spusched_tick occurs. This change routes mfc interrupts to the cpu where the controlling thread last ran, provided that cpu is on the same node as the spu (otherwise don't reroute interrupts). This should improve performance and provide a more predictable environment for processing spu exceptions. In the past we have seen concurrent delivery of spu exceptions to two cpus. This eliminates that concern. Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
-rw-r--r--arch/powerpc/platforms/cell/spu_priv1_mmio.c16
-rw-r--r--arch/powerpc/platforms/cell/spufs/sched.c4
-rw-r--r--arch/powerpc/platforms/cell/spufs/spufs.h1
-rw-r--r--arch/powerpc/platforms/cell/spufs/switch.c8
4 files changed, 26 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/cell/spu_priv1_mmio.c b/arch/powerpc/platforms/cell/spu_priv1_mmio.c
index 67fa7247b80..906a0a2a9fe 100644
--- a/arch/powerpc/platforms/cell/spu_priv1_mmio.c
+++ b/arch/powerpc/platforms/cell/spu_priv1_mmio.c
@@ -28,6 +28,7 @@
#include <linux/io.h>
#include <linux/mutex.h>
#include <linux/device.h>
+#include <linux/sched.h>
#include <asm/spu.h>
#include <asm/spu_priv1.h>
@@ -75,8 +76,19 @@ static u64 int_stat_get(struct spu *spu, int class)
static void cpu_affinity_set(struct spu *spu, int cpu)
{
- u64 target = iic_get_target_id(cpu);
- u64 route = target << 48 | target << 32 | target << 16;
+ u64 target;
+ u64 route;
+
+ if (nr_cpus_node(spu->node)) {
+ cpumask_t spumask = node_to_cpumask(spu->node);
+ cpumask_t cpumask = node_to_cpumask(cpu_to_node(cpu));
+
+ if (!cpus_intersects(spumask, cpumask))
+ return;
+ }
+
+ target = iic_get_target_id(cpu);
+ route = target << 48 | target << 32 | target << 16;
out_be64(&spu->priv1->int_route_RW, route);
}
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 62280c292aa..1df7d6d152c 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -140,6 +140,9 @@ void __spu_update_sched_info(struct spu_context *ctx)
* if it is timesliced or preempted.
*/
ctx->cpus_allowed = current->cpus_allowed;
+
+ /* Save the current cpu id for spu interrupt routing. */
+ ctx->last_ran = raw_smp_processor_id();
}
void spu_update_sched_info(struct spu_context *ctx)
@@ -243,7 +246,6 @@ static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
spu_switch_log_notify(spu, ctx, SWITCH_LOG_START, 0);
spu_restore(&ctx->csa, spu);
spu->timestamp = jiffies;
- spu_cpu_affinity_set(spu, raw_smp_processor_id());
spu_switch_notify(spu, ctx);
ctx->state = SPU_STATE_RUNNABLE;
diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 7312745b754..dc3a215a6a2 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -121,6 +121,7 @@ struct spu_context {
cpumask_t cpus_allowed;
int policy;
int prio;
+ int last_ran;
/* statistics */
struct {
diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c
index 9748808b0f1..47c658051fc 100644
--- a/arch/powerpc/platforms/cell/spufs/switch.c
+++ b/arch/powerpc/platforms/cell/spufs/switch.c
@@ -1704,6 +1704,13 @@ static inline void restore_mfc_sr1(struct spu_state *csa, struct spu *spu)
eieio();
}
+static inline void set_int_route(struct spu_state *csa, struct spu *spu)
+{
+ struct spu_context *ctx = spu->ctx;
+
+ spu_cpu_affinity_set(spu, ctx->last_ran);
+}
+
static inline void restore_other_spu_access(struct spu_state *csa,
struct spu *spu)
{
@@ -2014,6 +2021,7 @@ static void restore_csa(struct spu_state *next, struct spu *spu)
check_ppuint_mb_stat(next, spu); /* Step 67. */
spu_invalidate_slbs(spu); /* Modified Step 68. */
restore_mfc_sr1(next, spu); /* Step 69. */
+ set_int_route(next, spu); /* NEW */
restore_other_spu_access(next, spu); /* Step 70. */
restore_spu_runcntl(next, spu); /* Step 71. */
restore_mfc_cntl(next, spu); /* Step 72. */