From 8297511530b0d2a281c796e738683951a59a020c Mon Sep 17 00:00:00 2001 From: David Mosberger-Tang Date: Mon, 25 Apr 2005 11:44:02 -0700 Subject: [PATCH] [IA64] add missing cpu_relax() in ITC syncing code Call cpu_relax() in busy-waiting loops of the ITC-syncing code. Signed-off-by: David Mosberger-Tang Signed-off-by: Tony Luck --- arch/ia64/kernel/smpboot.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index ca1536db33..dbc6b610cc 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -1,7 +1,7 @@ /* * SMP boot-related support * - * Copyright (C) 1998-2003 Hewlett-Packard Co + * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co * David Mosberger-Tang * * 01/05/16 Rohit Seth Moved SMP booting functions from smp.c to here. @@ -156,7 +156,8 @@ sync_master (void *arg) local_irq_save(flags); { for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) { - while (!go[MASTER]); + while (!go[MASTER]) + cpu_relax(); go[MASTER] = 0; go[SLAVE] = ia64_get_itc(); } @@ -179,7 +180,8 @@ get_delta (long *rt, long *master) for (i = 0; i < NUM_ITERS; ++i) { t0 = ia64_get_itc(); go[MASTER] = 1; - while (!(tm = go[SLAVE])); + while (!(tm = go[SLAVE])) + cpu_relax(); go[SLAVE] = 0; t1 = ia64_get_itc(); @@ -258,7 +260,8 @@ ia64_sync_itc (unsigned int master) return; } - while (go[MASTER]); /* wait for master to be ready */ + while (go[MASTER]) + cpu_relax(); /* wait for master to be ready */ spin_lock_irqsave(&itc_sync_lock, flags); { -- 2.39.5