[tip:smp/hotplug] tile: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()

[tip-bot for Yong Zhang]

Commit-ID:  8efdfc3a4ed009c978dab6609d15fb958e7cff12
Gitweb:     http://git.kernel.org/tip/8efdfc3a4ed009c978dab6609d15fb958e7cff12
Author:     Yong Zhang <yong.zhang0@xxxxxxxxx>
AuthorDate: Tue, 29 May 2012 15:16:00 +0800
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 5 Jun 2012 17:27:12 +0200

tile: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()

ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock
protects only the call_function data structure itself, but it's
completely unrelated to cpu_online_mask. The mask to which the IPIs
are sent is calculated before call_function.lock is taken in
smp_call_function_many(), so the locking around set_cpu_online() is
pointless and can be removed.

[ tglx: Massaged changelog ]

Signed-off-by: Yong Zhang <yong.zhang0@xxxxxxxxx>
Cc: ralf@xxxxxxxxxxxxxx
Cc: sshtylyov@xxxxxxxxxx
Cc: david.daney@xxxxxxxxxx
Cc: nikunj@xxxxxxxxxxxxxxxxxx
Cc: paulmck@xxxxxxxxxxxxxxxxxx
Cc: axboe@xxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1338275765-3217-6-git-send-email-yong.zhang0@xxxxxxxxx
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 arch/tile/kernel/smpboot.c |   10 ----------
 1 files changed, 0 insertions(+), 10 deletions(-)

diff --git a/arch/tile/kernel/smpboot.c b/arch/tile/kernel/smpboot.c
index 84873fb..e686c5a 100644
--- a/arch/tile/kernel/smpboot.c
+++ b/arch/tile/kernel/smpboot.c
@@ -198,17 +198,7 @@ void __cpuinit online_secondary(void)
 
 	notify_cpu_starting(smp_processor_id());
 
-	/*
-	 * We need to hold call_lock, so there is no inconsistency
-	 * between the time smp_call_function() determines number of
-	 * IPI recipients, and the time when the determination is made
-	 * for which cpus receive the IPI. Holding this
-	 * lock helps us to not include this cpu in a currently in progress
-	 * smp_call_function().
-	 */
-	ipi_call_lock();
 	set_cpu_online(smp_processor_id(), 1);
-	ipi_call_unlock();
 	__get_cpu_var(cpu_state) = CPU_ONLINE;
 
 	/* Set up tile-specific state for this cpu. */
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/