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Subject[patch 01/28] pm_qos: remove BKL
pm_qos_power_open got its lock_kernel() calls from the open() pushdown.  A
look at the code shows that the only global resources accessed are
pm_qos_array and "name". pm_qos_array doesn't change (things pointed to
therein do change, but they are atomics and/or are protected by
pm_qos_lock). Accesses to "name" are totally unprotected with or without
the BKL; that will be fixed shortly. The BKL is not helpful here; take it
out.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Cc: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index dfdec52..d96b83e 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -29,7 +29,6 @@

#include <linux/pm_qos_params.h>
#include <linux/sched.h>
-#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/time.h>
@@ -352,20 +351,15 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp)
int ret;
long pm_qos_class;

- lock_kernel();
pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
if (pm_qos_class >= 0) {
filp->private_data = (void *)pm_qos_class;
sprintf(name, "process_%d", current->pid);
ret = pm_qos_add_requirement(pm_qos_class, name,
PM_QOS_DEFAULT_VALUE);
- if (ret >= 0) {
- unlock_kernel();
+ if (ret >= 0)
return 0;
- }
}
- unlock_kernel();
-
return -EPERM;
}




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