Straggler: Connector: Use this_cpu_operations

From: Christoph Lameter
Date: Tue Dec 07 2010 - 10:46:37 EST


The patch was originally in the use cpuops patchset but it needs an
inc_return and is therefore dependant on an extension of the cpu ops.
Fixed up and verified that it compiles.


Subject: Connector: Use this_cpu operations

get_seq can benefit from this_cpu_operations. Address calculation is avoided
and the increment is done using an xadd.

Cc: Scott James Remnant <scott@xxxxxxxxxx>
Cc: Mike Frysinger <vapier@xxxxxxxxxx>
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>

---
drivers/connector/cn_proc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/connector/cn_proc.c
===================================================================
--- linux-2.6.orig/drivers/connector/cn_proc.c 2010-12-07 09:40:48.000000000 -0600
+++ linux-2.6/drivers/connector/cn_proc.c 2010-12-07 09:41:13.000000000 -0600
@@ -43,9 +43,10 @@ static DEFINE_PER_CPU(__u32, proc_event_

static inline void get_seq(__u32 *ts, int *cpu)
{
- *ts = get_cpu_var(proc_event_counts)++;
+ preempt_disable();
+ *ts = __this_cpu_inc_return(proc_event_counts) -1;
*cpu = smp_processor_id();
- put_cpu_var(proc_event_counts);
+ preempt_enable();
}

void proc_fork_connector(struct task_struct *task)

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