From 7b3c92b85a65c2db1f542265bc98e1f9e3056eba Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Thu, 4 Jul 2019 15:13:23 -0700
Subject: [PATCH] sched/core: Convert get_task_struct() to return the task
Git-commit: 7b3c92b85a65c2db1f542265bc98e1f9e3056eba
Patch-mainline: v5.4-rc1
References: bsc#1149032
Returning the pointer that was passed in allows us to write
slightly more idiomatic code. Convert a few users.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Peter 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: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
include/linux/sched/task.h | 6 +++++-
kernel/events/core.c | 9 +++------
kernel/irq/manage.c | 3 +--
kernel/locking/rtmutex.c | 6 ++----
kernel/trace/trace_sched_wakeup.c | 3 +--
5 files changed, 12 insertions(+), 15 deletions(-)
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 0497091e40c1..3d90ed8f75f0 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -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);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 026a14541a38..ea5e8139fe62 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -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;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e8f7f179bf77..9d50fbe5531a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -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
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index fa83d36e30c6..2874bf556162 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -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 */
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 743b2b520d34..5e43b9664eca 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -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);
--
2.16.4