Commit 7b3c92b8 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Ingo Molnar
Browse files

sched/core: Convert get_task_struct() to return the task 



Returning the pointer that was passed in allows us to write
slightly more idiomatic code.  Convert a few users.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190704221323.24290-1-willy@infradead.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 3c29e651

include/linux/sched/task.h

+5 −1
Original line number Diff line number Diff line
@@ -105,7 +105,11 @@ extern void sched_exec(void); 
#define sched_exec()   {}

#endif



#define get_task_struct(tsk) do { refcount_inc(&(tsk)->usage); } while(0)

static inline struct task_struct *get_task_struct(struct task_struct *t)

{

	refcount_inc(&t->usage);

	return t;

}



extern void __put_task_struct(struct task_struct *t);

kernel/events/core.c

+3 −6
Original line number Diff line number Diff line
@@ -4089,10 +4089,8 @@ alloc_perf_context(struct pmu *pmu, struct task_struct *task) 
		return NULL;



	__perf_event_init_context(ctx);

	if (task) {

		ctx->task = task;

		get_task_struct(task);

	}

	if (task)

		ctx->task = get_task_struct(task);

	ctx->pmu = pmu;



	return ctx;
@@ -10355,8 +10353,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, 
		 * and we cannot use the ctx information because we need the

		 * pmu before we get a ctx.

		 */

		get_task_struct(task);

		event->hw.target = task;

		event->hw.target = get_task_struct(task);

	}



	event->clock = &local_clock;

kernel/irq/manage.c

+1 −2
Original line number Diff line number Diff line
@@ -1255,8 +1255,7 @@ setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary) 
	 * the thread dies to avoid that the interrupt code

	 * references an already freed task_struct.

	 */

	get_task_struct(t);

	new->thread = t;

	new->thread = get_task_struct(t);

	/*

	 * Tell the thread to set its affinity. This is

	 * important for shared interrupt handlers as we do

kernel/locking/rtmutex.c

+2 −4
Original line number Diff line number Diff line
@@ -628,8 +628,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, 
		}



		/* [10] Grab the next task, i.e. owner of @lock */

		task = rt_mutex_owner(lock);

		get_task_struct(task);

		task = get_task_struct(rt_mutex_owner(lock));

		raw_spin_lock(&task->pi_lock);



		/*
@@ -709,8 +708,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, 
	}



	/* [10] Grab the next task, i.e. the owner of @lock */

	task = rt_mutex_owner(lock);

	get_task_struct(task);

	task = get_task_struct(rt_mutex_owner(lock));

	raw_spin_lock(&task->pi_lock);



	/* [11] requeue the pi waiters if necessary */

kernel/trace/trace_sched_wakeup.c

+1 −2
Original line number Diff line number Diff line
@@ -579,8 +579,7 @@ probe_wakeup(void *ignore, struct task_struct *p) 
	else

		tracing_dl = 0;



	wakeup_task = p;

	get_task_struct(wakeup_task);

	wakeup_task = get_task_struct(p);



	local_save_flags(flags);