From: Cai Huoqing caihuoqing@baidu.com
[ Upstream commit 800977f6f32e452cba6b04ef21d2f5383ca29209 ]
Add a new helper function kthread_run_on_cpu(), which includes kthread_create_on_cpu/wake_up_process().
In some cases, use kthread_run_on_cpu() directly instead of kthread_create_on_node/kthread_bind/wake_up_process() or kthread_create_on_cpu/wake_up_process() or kthreadd_create/kthread_bind/wake_up_process() to simplify the code.
[akpm@linux-foundation.org: export kthread_create_on_cpu to modules]
Link: https://lkml.kernel.org/r/20211022025711.3673-2-caihuoqing@baidu.com Signed-off-by: Cai Huoqing caihuoqing@baidu.com Cc: Bernard Metzler bmt@zurich.ibm.com Cc: Cai Huoqing caihuoqing@baidu.com Cc: Daniel Bristot de Oliveira bristot@kernel.org Cc: Davidlohr Bueso dave@stgolabs.net Cc: Doug Ledford dledford@redhat.com Cc: Ingo Molnar mingo@redhat.com Cc: Jason Gunthorpe jgg@ziepe.ca Cc: Joel Fernandes (Google) joel@joelfernandes.org Cc: Josh Triplett josh@joshtriplett.org Cc: Lai Jiangshan jiangshanlai@gmail.com Cc: Mathieu Desnoyers mathieu.desnoyers@efficios.com Cc: "Paul E . McKenney" paulmck@kernel.org Cc: Steven Rostedt rostedt@goodmis.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Stable-dep-of: 08697bca9bbb ("trace/hwlat: Do not start per-cpu thread if it is already running") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/kthread.h | 25 +++++++++++++++++++++++++ kernel/kthread.c | 1 + 2 files changed, 26 insertions(+)
diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 346b0f269161a..db47aae7c481b 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -56,6 +56,31 @@ bool kthread_is_per_cpu(struct task_struct *k); __k; \ })
+/** + * kthread_run_on_cpu - create and wake a cpu bound thread. + * @threadfn: the function to run until signal_pending(current). + * @data: data ptr for @threadfn. + * @cpu: The cpu on which the thread should be bound, + * @namefmt: printf-style name for the thread. Format is restricted + * to "name.*%u". Code fills in cpu number. + * + * Description: Convenient wrapper for kthread_create_on_cpu() + * followed by wake_up_process(). Returns the kthread or + * ERR_PTR(-ENOMEM). + */ +static inline struct task_struct * +kthread_run_on_cpu(int (*threadfn)(void *data), void *data, + unsigned int cpu, const char *namefmt) +{ + struct task_struct *p; + + p = kthread_create_on_cpu(threadfn, data, cpu, namefmt); + if (!IS_ERR(p)) + wake_up_process(p); + + return p; +} + void free_kthread_struct(struct task_struct *k); void kthread_bind(struct task_struct *k, unsigned int cpu); void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask); diff --git a/kernel/kthread.c b/kernel/kthread.c index 5b37a8567168b..e319a1b62586e 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -523,6 +523,7 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), to_kthread(p)->cpu = cpu; return p; } +EXPORT_SYMBOL(kthread_create_on_cpu);
void kthread_set_per_cpu(struct task_struct *k, int cpu) {