Commit-ID: 1b034bd989aa4a396c13d305759c376c52595a97 Gitweb: http://git.kernel.org/tip/1b034bd989aa4a396c13d305759c376c52595a97 Author: Oleg Nesterov <o...@redhat.com> AuthorDate: Tue, 17 Nov 2015 18:05:23 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 23 Nov 2015 09:48:18 +0100
stop_machine: Make cpu_stop_queue_work() and stop_one_cpu_nowait() return bool Change cpu_stop_queue_work() to return true if the work was queued and change stop_one_cpu_nowait() to return the result of cpu_stop_queue_work(). This makes it more useful, for example now you can alloc cpu_stop_work for stop_one_cpu_nowait() and free it in the callback or if stop_one_cpu_nowait() fails, currently this is impossible because you can't know if @fn will be called or not. Also, this allows to kill cpu_stop_done->executed, see the next changes. Signed-off-by: Oleg Nesterov <o...@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Acked-by: Tejun Heo <t...@kernel.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Mike Galbraith <efa...@gmx.de> Cc: Milos Vyletel <mi...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Prarit Bhargava <pra...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/20151117170523.ga13...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- include/linux/stop_machine.h | 7 +++++-- kernel/stop_machine.c | 16 ++++++++++++---- 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 0adedca..9ef42e1 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -29,7 +29,7 @@ struct cpu_stop_work { int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg); int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *arg); -void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, +bool stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf); int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); @@ -65,7 +65,7 @@ static void stop_one_cpu_nowait_workfn(struct work_struct *work) preempt_enable(); } -static inline void stop_one_cpu_nowait(unsigned int cpu, +static inline bool stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf) { @@ -74,7 +74,10 @@ static inline void stop_one_cpu_nowait(unsigned int cpu, work_buf->fn = fn; work_buf->arg = arg; schedule_work(&work_buf->work); + return true; } + + return false; } static inline int stop_cpus(const struct cpumask *cpumask, diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 17f01a9..0ec1f16 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -81,17 +81,21 @@ static void __cpu_stop_queue_work(struct cpu_stopper *stopper, } /* queue @work to @stopper. if offline, @work is completed immediately */ -static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work) +static bool cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work) { struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); unsigned long flags; + bool enabled; spin_lock_irqsave(&stopper->lock, flags); - if (stopper->enabled) + enabled = stopper->enabled; + if (enabled) __cpu_stop_queue_work(stopper, work); else cpu_stop_signal_done(work->done, false); spin_unlock_irqrestore(&stopper->lock, flags); + + return enabled; } /** @@ -297,12 +301,16 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void * * * CONTEXT: * Don't care. + * + * RETURNS: + * true if cpu_stop_work was queued successfully and @fn will be called, + * false otherwise. */ -void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, +bool stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf) { *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, }; - cpu_stop_queue_work(cpu, work_buf); + return cpu_stop_queue_work(cpu, work_buf); } /* static data for stop_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/
