Messages in this thread Patch in this message | | | From | Nadav Amit <> | Subject | [PATCH 9/9] x86/apic: Use non-atomic operations when possible | Date | Wed, 12 Jun 2019 23:48:13 -0700 |
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Using __clear_bit() and __cpumask_clear_cpu() is more efficient than using their atomic counterparts. Use them when atomicity is not needed, such as when manipulating bitmasks that are on the stack.
Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Nadav Amit <namit@vmware.com> --- arch/x86/kernel/apic/apic_flat_64.c | 4 ++-- arch/x86/kernel/apic/x2apic_cluster.c | 2 +- arch/x86/kernel/smp.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c index bf083c3f1d73..bbdca603f94a 100644 --- a/arch/x86/kernel/apic/apic_flat_64.c +++ b/arch/x86/kernel/apic/apic_flat_64.c @@ -78,7 +78,7 @@ flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) int cpu = smp_processor_id(); if (cpu < BITS_PER_LONG) - clear_bit(cpu, &mask); + __clear_bit(cpu, &mask); _flat_send_IPI_mask(mask, vector); } @@ -92,7 +92,7 @@ static void flat_send_IPI_allbutself(int vector) unsigned long mask = cpumask_bits(cpu_online_mask)[0]; if (cpu < BITS_PER_LONG) - clear_bit(cpu, &mask); + __clear_bit(cpu, &mask); _flat_send_IPI_mask(mask, vector); } diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c index 7685444a106b..609e499387a1 100644 --- a/arch/x86/kernel/apic/x2apic_cluster.c +++ b/arch/x86/kernel/apic/x2apic_cluster.c @@ -50,7 +50,7 @@ __x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest) cpumask_copy(tmpmsk, mask); /* If IPI should not be sent to self, clear current CPU */ if (apic_dest != APIC_DEST_ALLINC) - cpumask_clear_cpu(smp_processor_id(), tmpmsk); + __cpumask_clear_cpu(smp_processor_id(), tmpmsk); /* Collapse cpus in a cluster so a single IPI per cluster is sent */ for_each_cpu(cpu, tmpmsk) { diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 4693e2f3a03e..96421f97e75c 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -144,7 +144,7 @@ void native_send_call_func_ipi(const struct cpumask *mask) } cpumask_copy(allbutself, cpu_online_mask); - cpumask_clear_cpu(smp_processor_id(), allbutself); + __cpumask_clear_cpu(smp_processor_id(), allbutself); if (cpumask_equal(mask, allbutself) && cpumask_equal(cpu_online_mask, cpu_callout_mask)) -- 2.20.1
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