android_kernel_motorola_sm6225/include/asm-i386/mach-default/mach_ipi.h
Zwane Mwaikambo 329d400f47 [PATCH] x86_64/i386: Remove preempt disable calls in lowlevel IPI
I noticed that some lowlevel send_IPI_mask helpers had a hotplug/preempt
race whereupon the cpu_online_map was read before disabling preemption;

...
cpumask_t mask = cpu_online_map;
int cpu = get_cpu();
cpu_clear(cpu, mask);
...

But then i realised that there is no need for these lowlevel functions to
be going through all this trouble when all the callers are already made
hotplug/preempt safe.

Signed-off-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 19:01:57 -08:00

51 lines
1.1 KiB
C

#ifndef __ASM_MACH_IPI_H
#define __ASM_MACH_IPI_H
void send_IPI_mask_bitmask(cpumask_t mask, int vector);
void __send_IPI_shortcut(unsigned int shortcut, int vector);
extern int no_broadcast;
static inline void send_IPI_mask(cpumask_t mask, int vector)
{
send_IPI_mask_bitmask(mask, vector);
}
static inline void __local_send_IPI_allbutself(int vector)
{
if (no_broadcast) {
cpumask_t mask = cpu_online_map;
cpu_clear(smp_processor_id(), mask);
send_IPI_mask(mask, vector);
} else
__send_IPI_shortcut(APIC_DEST_ALLBUT, vector);
}
static inline void __local_send_IPI_all(int vector)
{
if (no_broadcast)
send_IPI_mask(cpu_online_map, vector);
else
__send_IPI_shortcut(APIC_DEST_ALLINC, vector);
}
static inline void send_IPI_allbutself(int vector)
{
/*
* if there are no other CPUs in the system then we get an APIC send
* error if we try to broadcast, thus avoid sending IPIs in this case.
*/
if (!(num_online_cpus() > 1))
return;
__local_send_IPI_allbutself(vector);
return;
}
static inline void send_IPI_all(int vector)
{
__local_send_IPI_all(vector);
}
#endif /* __ASM_MACH_IPI_H */