Commit-ID: c6f4459fc3ba532e896cb678e29b45cb985f82bf Gitweb: http://git.kernel.org/tip/c6f4459fc3ba532e896cb678e29b45cb985f82bf Author: Chuansheng Liu <chuansheng....@intel.com> AuthorDate: Thu, 4 Sep 2014 15:17:54 +0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 19 Sep 2014 12:35:15 +0200
smp: Add new wake_up_all_idle_cpus() function Currently kick_all_cpus_sync() can break non-polling idle cpus thru IPI interrupts. But sometimes we need to break the polling idle cpus immediately to reselect the suitable c-state, also for non-idle cpus, we need to do nothing if we try to wake up them. Here adding one new function wake_up_all_idle_cpus() to let all cpus out of idle based on function wake_up_if_idle(). Signed-off-by: Chuansheng Liu <chuansheng....@intel.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: daniel.lezc...@linaro.org Cc: r...@rjwysocki.net Cc: linux...@vger.kernel.org Cc: changcheng....@intel.com Cc: xiaoming.w...@intel.com Cc: souvik.k.chakrava...@intel.com Cc: l...@amacapital.net Cc: Andrew Morton <a...@linux-foundation.org> Cc: Christoph Hellwig <h...@infradead.org> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: Geert Uytterhoeven <geert+rene...@glider.be> Cc: Jan Kara <j...@suse.cz> Cc: Jens Axboe <ax...@fb.com> Cc: Jens Axboe <ax...@kernel.dk> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Michal Hocko <mho...@suse.cz> Cc: Paul Gortmaker <paul.gortma...@windriver.com> Cc: Roman Gushchin <kl...@yandex-team.ru> Cc: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1409815075-4180-2-git-send-email-chuansheng....@intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- include/linux/smp.h | 2 ++ kernel/smp.c | 22 ++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/linux/smp.h b/include/linux/smp.h index 34347f2..93dff5f 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -100,6 +100,7 @@ int smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, void *info, int wait); void kick_all_cpus_sync(void); +void wake_up_all_idle_cpus(void); /* * Generic and arch helpers @@ -148,6 +149,7 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, } static inline void kick_all_cpus_sync(void) { } +static inline void wake_up_all_idle_cpus(void) { } #endif /* !SMP */ diff --git a/kernel/smp.c b/kernel/smp.c index aff8aa1..9e0d0b2 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -13,6 +13,7 @@ #include <linux/gfp.h> #include <linux/smp.h> #include <linux/cpu.h> +#include <linux/sched.h> #include "smpboot.h" @@ -699,3 +700,24 @@ void kick_all_cpus_sync(void) smp_call_function(do_nothing, NULL, 1); } EXPORT_SYMBOL_GPL(kick_all_cpus_sync); + +/** + * wake_up_all_idle_cpus - break all cpus out of idle + * wake_up_all_idle_cpus try to break all cpus which is in idle state even + * including idle polling cpus, for non-idle cpus, we will do nothing + * for them. + */ +void wake_up_all_idle_cpus(void) +{ + int cpu; + + preempt_disable(); + for_each_online_cpu(cpu) { + if (cpu == smp_processor_id()) + continue; + + wake_up_if_idle(cpu); + } + preempt_enable(); +} +EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
