From b6f6b98a4e91fcf31db7de54c3aa86252fc6fb5f Mon Sep 17 00:00:00 2001 From: Sonny Rao Date: Sat, 12 Jul 2008 09:00:26 +1000 Subject: [PATCH] powerpc: Don't spin on sync instruction at boot time Push the sync below the secondary smp init hold loop and comment its purpose. This should speed up boot by reducing global traffic during the single-threaded portion of boot. Signed-off-by: Sonny Rao Signed-off-by: Milton Miller Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/head_64.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index ecced1eb03ae..cc8fb474d520 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -1198,7 +1198,6 @@ _GLOBAL(generic_secondary_smp_init) 3: HMT_LOW lbz r23,PACAPROCSTART(r13) /* Test if this processor should */ /* start. */ - sync #ifndef CONFIG_SMP b 3b /* Never go on non-SMP */ @@ -1206,6 +1205,8 @@ _GLOBAL(generic_secondary_smp_init) cmpwi 0,r23,0 beq 3b /* Loop until told to go */ + sync /* order paca.run and cur_cpu_spec */ + /* See if we need to call a cpu state restore handler */ LOAD_REG_IMMEDIATE(r23, cur_cpu_spec) ld r23,0(r23)