[PATCH] s390: external call performance
The kernel uses the SIGP external call order code to signal other CPUs. When
running with dedicated CPUs external calls don't get delivered immediately but
within a fixed polling invervall. This can lead to delays where the system
appears to do nothing. Replace the SIGP external call order with the SIGP
emergency call order since this one gets delivered immediately.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 642572a..da77f00 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -375,7 +375,7 @@
* Set signaling bit in lowcore of target cpu and kick it
*/
set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
- while(signal_processor(cpu, sigp_external_call) == sigp_busy)
+ while(signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
udelay(10);
}
@@ -394,7 +394,7 @@
* Set signaling bit in lowcore of target cpu and kick it
*/
set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
- while (signal_processor(cpu, sigp_external_call) == sigp_busy)
+ while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
udelay(10);
}
}
@@ -751,9 +751,9 @@
unsigned int cpu;
int i;
- /* request the 0x1202 external interrupt */
- if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
- panic("Couldn't request external interrupt 0x1202");
+ /* request the 0x1201 emergency signal external interrupt */
+ if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
+ panic("Couldn't request external interrupt 0x1201");
smp_check_cpus(max_cpus);
memset(lowcore_ptr,0,sizeof(lowcore_ptr));
/*