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sparc64: Call xcall_deliver() directly in some cases.
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For these cases the callers make sure:

1) The cpus indicated are online.

2) The current cpu is not in the list of indicated cpus.

Therefore we can pass a pointer to the mask directly.

One of the motivations in this transformation is to make use of
"&cpumask_of_cpu(cpu)" which evaluates to a pointer to constant
data in the kernel and thus takes up no stack space.

Hopefully someone in the future will change the interface of
arch_send_call_function_ipi() such that it passes a const cpumask_t
pointer so that this will optimize ever further.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Aug 4, 2008
1 parent cd5bc89 commit 1992663
Showing 1 changed file with 10 additions and 23 deletions.
33 changes: 10 additions & 23 deletions arch/sparc64/kernel/smp.c
Original file line number Diff line number Diff line change
Expand Up @@ -792,16 +792,15 @@ extern unsigned long xcall_call_function;

void arch_send_call_function_ipi(cpumask_t mask)
{
smp_cross_call_masked(&xcall_call_function, 0, 0, 0, mask);
xcall_deliver((u64) &xcall_call_function, 0, 0, &mask);
}

extern unsigned long xcall_call_function_single;

void arch_send_call_function_single_ipi(int cpu)
{
cpumask_t mask = cpumask_of_cpu(cpu);

smp_cross_call_masked(&xcall_call_function_single, 0, 0, 0, mask);
xcall_deliver((u64) &xcall_call_function_single, 0, 0,
&cpumask_of_cpu(cpu));
}

/* Send cross call to all processors except self. */
Expand Down Expand Up @@ -959,24 +958,6 @@ void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
put_cpu();
}

static void __smp_receive_signal_mask(cpumask_t mask)
{
smp_cross_call_masked(&xcall_receive_signal, 0, 0, 0, mask);
}

void smp_receive_signal(int cpu)
{
cpumask_t mask = cpumask_of_cpu(cpu);

if (cpu_online(cpu))
__smp_receive_signal_mask(mask);
}

void smp_receive_signal_client(int irq, struct pt_regs *regs)
{
clear_softint(1 << irq);
}

void smp_new_mmu_context_version_client(int irq, struct pt_regs *regs)
{
struct mm_struct *mm;
Expand Down Expand Up @@ -1374,7 +1355,13 @@ void __init smp_cpus_done(unsigned int max_cpus)

void smp_send_reschedule(int cpu)
{
smp_receive_signal(cpu);
xcall_deliver((u64) &xcall_receive_signal, 0, 0,
&cpumask_of_cpu(cpu));
}

void smp_receive_signal_client(int irq, struct pt_regs *regs)
{
clear_softint(1 << irq);
}

/* This is a nop because we capture all other cpus
Expand Down

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