[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>

1 files changed, 5 insertions, 5 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 642572a8e334..da77f001af8d 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -375,7 +375,7 @@ static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
          * 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 @@ static void smp_ext_bitcall_others(ec_bit_sig sig)
                  * 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 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
         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));  
         /*