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[SPARC64]: Add SMT scheduling support for Niagara. 

The mapping is a simple "(cpuid >> 2) == core" for now.
Later we'll add more sophisticated code that will walk
the sun4v machine description and figure this out from
there.

We should also add core mappings for jaguar and panther
processors.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2006-03-08 16:09:19 -08:00
parent 17b0e199a1
commit 8935dced54
3 changed files with 29 additions and 0 deletions
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9
arch/sparc64/Kconfig
View File

@ -356,6 +356,15 @@ config SOLARIS_EMUL
endmenu
config SCHED_SMT
bool "SMT (Hyperthreading) scheduler support"
depends on SMP
default y
help
SMT scheduler support improves the CPU scheduler's decision making
when dealing with UltraSPARC cpus at a cost of slightly increased
overhead in some places. If unsure say N here.
config CMDLINE_BOOL
bool "Default bootloader kernel arguments"

18
arch/sparc64/kernel/smp.c
View File

@ -47,6 +47,8 @@ static unsigned char boot_cpu_id;
cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
cpumask_t phys_cpu_present_map __read_mostly = CPU_MASK_NONE;
cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly =
{ [0 ... NR_CPUS-1] = CPU_MASK_NONE };
static cpumask_t smp_commenced_mask;
static cpumask_t cpu_callout_map;
@ -1291,6 +1293,8 @@ int setup_profiling_timer(unsigned int multiplier)
/* Constrain the number of cpus to max_cpus. */
void __init smp_prepare_cpus(unsigned int max_cpus)
{
int i;
if (num_possible_cpus() > max_cpus) {
int instance, mid;
@ -1305,6 +1309,20 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
}
}
for_each_cpu(i) {
if (tlb_type == hypervisor) {
int j;
/* XXX get this mapping from machine description */
for_each_cpu(j) {
if ((j >> 2) == (i >> 2))
cpu_set(j, cpu_sibling_map[i]);
}
} else {
cpu_set(i, cpu_sibling_map[i]);
}
}
smp_store_cpu_info(boot_cpu_id);
}

2
include/asm-sparc64/smp.h
View File

@ -33,6 +33,8 @@
extern cpumask_t phys_cpu_present_map;
#define cpu_possible_map phys_cpu_present_map
extern cpumask_t cpu_sibling_map[NR_CPUS];
/*
* General functions that each host system must provide.
*/