stop_machine: Add function and caller debug info (a8b62fd0) · Commits · 戴 / test

include/linux/stop_machine.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@ typedef int (cpu_stop_fn_t)(void arg);
		struct cpu_stop_work {
		struct list_head list; /* cpu_stopper->works */
		cpu_stop_fn_t fn;
		unsigned long caller;
		void *arg;
		struct cpu_stop_done *done;
		};
		@@ -36,6 +37,8 @@ void stop_machine_park(int cpu);
		void stop_machine_unpark(int cpu);
		void stop_machine_yield(const struct cpumask *cpumask);

		extern void print_stop_info(const char log_lvl, struct task_struct task);

		#else /* CONFIG_SMP */

		#include <linux/workqueue.h>
		@@ -80,6 +83,8 @@ static inline bool stop_one_cpu_nowait(unsigned int cpu,
		return false;
		}

		static inline void print_stop_info(const char log_lvl, struct task_struct task) { }

		#endif /* CONFIG_SMP */

		/*

kernel/sched/core.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -6447,6 +6447,7 @@ void sched_show_task(struct task_struct *p)
		(unsigned long)task_thread_info(p)->flags);

		print_worker_info(KERN_INFO, p);
		print_stop_info(KERN_INFO, p);
		show_stack(p, NULL, KERN_INFO);
		put_task_stack(p);
		}

kernel/stop_machine.c

+24 −3

Original line number	Diff line number	Diff line
		@@ -42,11 +42,27 @@ struct cpu_stopper {
		struct list_head works; /* list of pending works */

		struct cpu_stop_work stop_work; /* for stop_cpus */
		unsigned long caller;
		cpu_stop_fn_t fn;
		};

		static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
		static bool stop_machine_initialized = false;

		void print_stop_info(const char log_lvl, struct task_struct task)
		{
		/*
		* If @task is a stopper task, it cannot migrate and task_cpu() is
		* stable.
		*/
		struct cpu_stopper *stopper = per_cpu_ptr(&cpu_stopper, task_cpu(task));

		if (task != stopper->thread)
		return;

		printk("%sStopper: %pS <- %pS\n", log_lvl, stopper->fn, (void *)stopper->caller);
		}

		/* static data for stop_cpus */
		static DEFINE_MUTEX(stop_cpus_mutex);
		static bool stop_cpus_in_progress;
		@@ -123,7 +139,7 @@ static bool cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
		int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
		{
		struct cpu_stop_done done;
		struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done };
		struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done, .caller = _RET_IP_ };

		cpu_stop_init_done(&done, 1);
		if (!cpu_stop_queue_work(cpu, &work))
		@@ -331,7 +347,8 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
		work1 = work2 = (struct cpu_stop_work){
		.fn = multi_cpu_stop,
		.arg = &msdata,
		.done = &done
		.done = &done,
		.caller = _RET_IP_,
		};

		cpu_stop_init_done(&done, 2);
		@@ -367,7 +384,7 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
		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, };
		*work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, .caller = _RET_IP_, };
		return cpu_stop_queue_work(cpu, work_buf);
		}

		@@ -487,6 +504,8 @@ repeat:
		int ret;

		/* cpu stop callbacks must not sleep, make in_atomic() == T */
		stopper->caller = work->caller;
		stopper->fn = fn;
		preempt_count_inc();
		ret = fn(arg);
		if (done) {
		@@ -495,6 +514,8 @@ repeat:
		cpu_stop_signal_done(done);
		}
		preempt_count_dec();
		stopper->fn = NULL;
		stopper->caller = 0;
		WARN_ONCE(preempt_count(),
		"cpu_stop: %ps(%p) leaked preempt count\n", fn, arg);
		goto repeat;

lib/dump_stack.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -12,6 +12,7 @@
		#include <linux/atomic.h>
		#include <linux/kexec.h>
		#include <linux/utsname.h>
		#include <linux/stop_machine.h>

		static char dump_stack_arch_desc_str[128];

		@@ -57,6 +58,7 @@ void dump_stack_print_info(const char *log_lvl)
		log_lvl, dump_stack_arch_desc_str);

		print_worker_info(log_lvl, current);
		print_stop_info(log_lvl, current);
		}

		/**

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