diff options
| author | Paul Mackerras <paulus@samba.org> | 2011-05-25 23:34:12 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-06-20 11:21:32 +1000 |
| commit | 9ca980dce523760ce04a798470d36fd5aa596b78 (patch) | |
| tree | bef37cf5113f56a8e77d6bebf2f57a9df9ae8c21 /arch/powerpc/kernel/smp.c | |
| parent | 7ac87abb8166b99584149fcfb2efef5773a078e9 (diff) | |
powerpc: Avoid extra indirect function call in sending IPIs
On many platforms (including pSeries), smp_ops->message_pass is always
smp_muxed_ipi_message_pass. This changes arch/powerpc/kernel/smp.c so
that if smp_ops->message_pass is NULL, it calls smp_muxed_ipi_message_pass
directly.
This means that a platform doesn't need to set both .message_pass and
.cause_ipi, only one of them. It is a slight performance improvement
in that it gets rid of an indirect function call at the expense of a
predictable conditional branch.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 8ebc6700b98..2975f64cf31 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -238,15 +238,25 @@ irqreturn_t smp_ipi_demux(void) } #endif /* CONFIG_PPC_SMP_MUXED_IPI */ +static inline void do_message_pass(int cpu, int msg) +{ + if (smp_ops->message_pass) + smp_ops->message_pass(cpu, msg); +#ifdef CONFIG_PPC_SMP_MUXED_IPI + else + smp_muxed_ipi_message_pass(cpu, msg); +#endif +} + void smp_send_reschedule(int cpu) { if (likely(smp_ops)) - smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE); + do_message_pass(cpu, PPC_MSG_RESCHEDULE); } void arch_send_call_function_single_ipi(int cpu) { - smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE); + do_message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE); } void arch_send_call_function_ipi_mask(const struct cpumask *mask) @@ -254,7 +264,7 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask) unsigned int cpu; for_each_cpu(cpu, mask) - smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION); + do_message_pass(cpu, PPC_MSG_CALL_FUNCTION); } #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC) @@ -268,7 +278,7 @@ void smp_send_debugger_break(void) for_each_online_cpu(cpu) if (cpu != me) - smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK); + do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK); } #endif |