i386: use smp_call_function_single() From: Alexey Dobriyan It will execute rdmsr and wrmsr only on the cpu we need. Signed-off-by: Alexey Dobriyan Signed-off-by: Andi Kleen --- arch/i386/kernel/msr.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) Index: linux/arch/i386/kernel/msr.c =================================================================== --- linux.orig/arch/i386/kernel/msr.c +++ linux/arch/i386/kernel/msr.c @@ -68,7 +68,6 @@ static inline int rdmsr_eio(u32 reg, u32 #ifdef CONFIG_SMP struct msr_command { - int cpu; int err; u32 reg; u32 data[2]; @@ -78,16 +77,14 @@ static void msr_smp_wrmsr(void *cmd_bloc { struct msr_command *cmd = (struct msr_command *)cmd_block; - if (cmd->cpu == smp_processor_id()) - cmd->err = wrmsr_eio(cmd->reg, cmd->data[0], cmd->data[1]); + cmd->err = wrmsr_eio(cmd->reg, cmd->data[0], cmd->data[1]); } static void msr_smp_rdmsr(void *cmd_block) { struct msr_command *cmd = (struct msr_command *)cmd_block; - if (cmd->cpu == smp_processor_id()) - cmd->err = rdmsr_eio(cmd->reg, &cmd->data[0], &cmd->data[1]); + cmd->err = rdmsr_eio(cmd->reg, &cmd->data[0], &cmd->data[1]); } static inline int do_wrmsr(int cpu, u32 reg, u32 eax, u32 edx) @@ -99,12 +96,11 @@ static inline int do_wrmsr(int cpu, u32 if (cpu == smp_processor_id()) { ret = wrmsr_eio(reg, eax, edx); } else { - cmd.cpu = cpu; cmd.reg = reg; cmd.data[0] = eax; cmd.data[1] = edx; - smp_call_function(msr_smp_wrmsr, &cmd, 1, 1); + smp_call_function_single(cpu, msr_smp_wrmsr, &cmd, 1, 1); ret = cmd.err; } preempt_enable(); @@ -120,10 +116,9 @@ static inline int do_rdmsr(int cpu, u32 if (cpu == smp_processor_id()) { ret = rdmsr_eio(reg, eax, edx); } else { - cmd.cpu = cpu; cmd.reg = reg; - smp_call_function(msr_smp_rdmsr, &cmd, 1, 1); + smp_call_function_single(cpu, msr_smp_rdmsr, &cmd, 1, 1); *eax = cmd.data[0]; *edx = cmd.data[1];