linux-IllusionX/include/linux/bottom_half.h
Peter Zijlstra 0bd3a173d7 sched/preempt, locking: Rework local_bh_{dis,en}able()
Currently local_bh_disable() is out-of-line for no apparent reason.
So inline it to save a few cycles on call/return nonsense, the
function body is a single add on x86 (a few loads and store extra on
load/store archs).

Also expose two new local_bh functions:

  __local_bh_{dis,en}able_ip(unsigned long ip, unsigned int cnt);

Which implement the actual local_bh_{dis,en}able() behaviour.

The next patch uses the exposed @cnt argument to optimize bh lock
functions.

With build fixes from Jacob Pan.

Cc: rjw@rjwysocki.net
Cc: rui.zhang@intel.com
Cc: jacob.jun.pan@linux.intel.com
Cc: Mike Galbraith <bitbucket@online.de>
Cc: hpa@zytor.com
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: lenb@kernel.org
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131119151338.GF3694@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13 17:32:27 +01:00

35 lines
796 B
C

#ifndef _LINUX_BH_H
#define _LINUX_BH_H
#include <linux/preempt.h>
#include <linux/preempt_mask.h>
#ifdef CONFIG_TRACE_IRQFLAGS
extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);
#else
static __always_inline void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
{
preempt_count_add(cnt);
barrier();
}
#endif
static inline void local_bh_disable(void)
{
__local_bh_disable_ip(_THIS_IP_, SOFTIRQ_DISABLE_OFFSET);
}
extern void _local_bh_enable(void);
extern void __local_bh_enable_ip(unsigned long ip, unsigned int cnt);
static inline void local_bh_enable_ip(unsigned long ip)
{
__local_bh_enable_ip(ip, SOFTIRQ_DISABLE_OFFSET);
}
static inline void local_bh_enable(void)
{
__local_bh_enable_ip(_THIS_IP_, SOFTIRQ_DISABLE_OFFSET);
}
#endif /* _LINUX_BH_H */