[PATCH] spufs: set irq affinity for running threads
For far, all SPU triggered interrupts always end up on
the first SMT thread, which is a bad solution.
This patch implements setting the affinity to the
CPU that was running last when entering execution on
an SPU. This should result in a significant reduction
in IPI calls and better cache locality for SPE thread
specific data.
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 7fbe78a..63aa52a 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -23,6 +23,7 @@
#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
+#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/types.h>
@@ -55,6 +56,7 @@
struct iic {
struct iic_regs __iomem *regs;
+ u8 target_id;
};
static DEFINE_PER_CPU(struct iic, iic);
@@ -172,12 +174,11 @@
return irq;
}
-static struct iic_regs __iomem *find_iic(int cpu)
+static int setup_iic(int cpu, struct iic *iic)
{
struct device_node *np;
int nodeid = cpu / 2;
unsigned long regs;
- struct iic_regs __iomem *iic_regs;
for (np = of_find_node_by_type(NULL, "cpu");
np;
@@ -188,20 +189,23 @@
if (!np) {
printk(KERN_WARNING "IIC: CPU %d not found\n", cpu);
- iic_regs = NULL;
- } else {
- regs = *(long *)get_property(np, "iic", NULL);
-
- /* hack until we have decided on the devtree info */
- regs += 0x400;
- if (cpu & 1)
- regs += 0x20;
-
- printk(KERN_DEBUG "IIC for CPU %d at %lx\n", cpu, regs);
- iic_regs = __ioremap(regs, sizeof(struct iic_regs),
- _PAGE_NO_CACHE);
+ iic->regs = NULL;
+ iic->target_id = 0xff;
+ return -ENODEV;
}
- return iic_regs;
+
+ regs = *(long *)get_property(np, "iic", NULL);
+
+ /* hack until we have decided on the devtree info */
+ regs += 0x400;
+ if (cpu & 1)
+ regs += 0x20;
+
+ printk(KERN_DEBUG "IIC for CPU %d at %lx\n", cpu, regs);
+ iic->regs = __ioremap(regs, sizeof(struct iic_regs),
+ _PAGE_NO_CACHE);
+ iic->target_id = (nodeid << 4) + ((cpu & 1) ? 0xf : 0xe);
+ return 0;
}
#ifdef CONFIG_SMP
@@ -227,6 +231,12 @@
out_be64(&per_cpu(iic, cpu).regs->generate, (IIC_NUM_IPIS - 1 - mesg) << 4);
}
+u8 iic_get_target_id(int cpu)
+{
+ return per_cpu(iic, cpu).target_id;
+}
+EXPORT_SYMBOL_GPL(iic_get_target_id);
+
static irqreturn_t iic_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
{
smp_message_recv(iic_irq_to_ipi(irq), regs);
@@ -276,7 +286,7 @@
irq_offset = 0;
for_each_cpu(cpu) {
iic = &per_cpu(iic, cpu);
- iic->regs = find_iic(cpu);
+ setup_iic(cpu, iic);
if (iic->regs)
out_be64(&iic->regs->prio, 0xff);
}