diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-02 09:03:17 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-02 09:03:17 +0300 |
| commit | 888411be09739443271d254c9d8c1f5188c05509 (patch) | |
| tree | f975a500cddf693695e3091da70f468296969491 | |
| parent | 7d6a31c394722c914c61292b457e1999c8bef5ea (diff) | |
| parent | c0edbd4a1693600d6eb9e2faad452638c35391f7 (diff) | |
| download | linux-888411be09739443271d254c9d8c1f5188c05509.tar.xz | |
Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 irq update from Ingo Molnar:
"A single commit that micro-optimizes an IRQ vectors code path in the
CPU offlining code"
* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/irq: Optimize free vector check in the CPU offline path
| -rw-r--r-- | arch/x86/kernel/irq.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 4d8183b5f113..f34fe7444836 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -394,6 +394,9 @@ int check_irq_vectors_for_cpu_disable(void) !cpumask_subset(&affinity_new, &online_new)) this_count++; } + /* No need to check any further. */ + if (!this_count) + return 0; count = 0; for_each_online_cpu(cpu) { @@ -411,8 +414,10 @@ int check_irq_vectors_for_cpu_disable(void) for (vector = FIRST_EXTERNAL_VECTOR; vector < first_system_vector; vector++) { if (!test_bit(vector, used_vectors) && - IS_ERR_OR_NULL(per_cpu(vector_irq, cpu)[vector])) - count++; + IS_ERR_OR_NULL(per_cpu(vector_irq, cpu)[vector])) { + if (++count == this_count) + return 0; + } } } |