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| author | David Mosberger-Tang <davidm@hpl.hp.com> | 2005-04-25 11:44:02 -0700 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2005-04-25 11:44:02 -0700 |
| commit | 8297511530b0d2a281c796e738683951a59a020c (patch) | |
| tree | 3ade89d674db6b0791ca72704478214d0bb56ad1 /arch/ia64 | |
| parent | bf1cf98fa941fea5e630e341db4a294d531aaa3e (diff) | |
| download | linux-3.10-8297511530b0d2a281c796e738683951a59a020c.tar.gz linux-3.10-8297511530b0d2a281c796e738683951a59a020c.tar.bz2 linux-3.10-8297511530b0d2a281c796e738683951a59a020c.zip | |
[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 <davidm@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/kernel/smpboot.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index ca1536db339..dbc6b610cc6 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 <davidm@hpl.hp.com> * * 01/05/16 Rohit Seth <rohit.seth@intel.com> 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); { |