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Commit d958f143 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Andi Kleen
Browse files

[PATCH] i386: use smp_call_function_single() 



It will execute rdmsr and wrmsr only on the cpu we need.

Signed-off-by: default avatarAlexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent edf8dd36

arch/i386/kernel/msr.c

+4 −9
Original line number Diff line number Diff line
@@ -68,7 +68,6 @@ static inline int rdmsr_eio(u32 reg, u32 *eax, u32 *edx) 
#ifdef CONFIG_SMP



struct msr_command {

	int cpu;

	int err;

	u32 reg;

	u32 data[2];
@@ -78,7 +77,6 @@ static void msr_smp_wrmsr(void *cmd_block) 
{

	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]);

}
@@ -86,7 +84,6 @@ 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]);

}
@@ -99,12 +96,11 @@ static inline int do_wrmsr(int cpu, u32 reg, u32 eax, u32 edx) 
	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 reg, u32 * eax, u32 * edx) 
	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];