From: Ye Liu <[email protected]> Replace the manual rcu_read_lock()/rcu_read_unlock() and guard(rcu) pairs combined with for_each_process(), for_each_thread() and for_each_process_thread() loops across kernel/ with the for_each_*_rcu() macros.
No functional change. Signed-off-by: Ye Liu <[email protected]> --- kernel/cpu.c | 4 +--- kernel/freezer.c | 4 +--- kernel/hung_task.c | 7 ++----- kernel/locking/lockdep.c | 4 +--- kernel/rcu/update.c | 4 +--- kernel/sched/core.c | 3 +-- kernel/sched/debug.c | 4 +--- kernel/trace/fgraph.c | 8 ++------ kernel/unwind/deferred.c | 3 +-- 9 files changed, 11 insertions(+), 30 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index b3c8553d7bd6..bc70fd21561a 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1254,8 +1254,7 @@ void clear_tasks_mm_cpumask(int cpu) * full-fledged tasklist_lock. */ WARN_ON(cpu_online(cpu)); - rcu_read_lock(); - for_each_process(p) { + for_each_process_rcu(p) { struct task_struct *t; /* @@ -1268,7 +1267,6 @@ void clear_tasks_mm_cpumask(int cpu) arch_clear_mm_cpumask_cpu(cpu, t->mm); task_unlock(t); } - rcu_read_unlock(); } /* Take this CPU down. */ diff --git a/kernel/freezer.c b/kernel/freezer.c index a76bf957fb32..a27b2382fda9 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -217,11 +217,9 @@ void thaw_process(struct task_struct *p) { struct task_struct *t; - rcu_read_lock(); - for_each_thread(p, t) { + for_each_thread_rcu(p, t) { __thaw_task(t); } - rcu_read_unlock(); } /** diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 6fcc94ce4ca9..76871f78497f 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -315,8 +315,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) return; this_round_count = 0; - rcu_read_lock(); - for_each_process_thread(g, t) { + for_each_process_thread_rcu(g, t) { if (!max_count--) goto unlock; if (time_after(jiffies, last_break + HUNG_TASK_LOCK_BREAK)) { @@ -337,9 +336,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) hung_task_info(t, timeout, this_round_count); } } - unlock: - rcu_read_unlock(); - +unlock: if (!this_round_count) return; diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index c56a7f91d72e..9c3dce0f0c4b 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -6834,15 +6834,13 @@ void debug_show_all_locks(void) } pr_warn("\nShowing all locks held in the system:\n"); - rcu_read_lock(); - for_each_process_thread(g, p) { + for_each_process_thread_rcu(g, p) { if (!p->lockdep_depth) continue; lockdep_print_held_locks(p); touch_nmi_watchdog(); touch_all_softlockup_watchdogs(); } - rcu_read_unlock(); pr_warn("\n"); pr_warn("=============================================\n\n"); diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 2a778b8ab4ad..c48a84a0da82 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -548,15 +548,13 @@ void synchronize_rcu_trivial_preempt(void) struct task_struct *t; smp_mb(); // Order prior accesses before grace-period start. - rcu_read_lock(); // Protect task list. - for_each_process_thread(g, t) { + for_each_process_thread_rcu(g, t) { if (t == current) continue; // Don't deadlock on ourselves! // Order later rcu_read_lock() on other tasks after QS. while (smp_load_acquire(&t->rcu_trivial_preempt_nesting)) continue; } - rcu_read_unlock(); } EXPORT_SYMBOL_GPL(synchronize_rcu_trivial_preempt); #endif // #if IS_ENABLED(CONFIG_TRIVIAL_PREEMPT_RCU) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0697ed0f1c3d..a41cdd2ff02f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2005,8 +2005,7 @@ static void uclamp_sync_util_min_rt_default(void) smp_mb__after_spinlock(); read_unlock(&tasklist_lock); - guard(rcu)(); - for_each_process_thread(g, p) + for_each_process_thread_rcu(g, p) uclamp_update_util_min_rt_default(p); } diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 72236db67983..8f37b1a7adfe 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -1029,14 +1029,12 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) #endif "\n"); - rcu_read_lock(); - for_each_process_thread(g, p) { + for_each_process_thread_rcu(g, p) { if (task_cpu(p) != rq_cpu) continue; print_task(m, rq, p); } - rcu_read_unlock(); } void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 40d373d65f9b..e522433ec8a5 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -1057,11 +1057,10 @@ static int alloc_retstack_tasklist(unsigned long **ret_stack_list) } } - rcu_read_lock(); - for_each_process_thread(g, t) { + for_each_process_thread_rcu(g, t) { if (start == end) { ret = -EAGAIN; - goto unlock; + goto free; } if (t->ret_stack == NULL) { @@ -1074,9 +1073,6 @@ static int alloc_retstack_tasklist(unsigned long **ret_stack_list) t->ret_stack = ret_stack_list[start++]; } } - -unlock: - rcu_read_unlock(); free: for (i = start; i < end; i++) kmem_cache_free(fgraph_stack_cachep, ret_stack_list[i]); diff --git a/kernel/unwind/deferred.c b/kernel/unwind/deferred.c index 5bea47314254..61fe2d4727ce 100644 --- a/kernel/unwind/deferred.c +++ b/kernel/unwind/deferred.c @@ -319,9 +319,8 @@ void unwind_deferred_cancel(struct unwind_work *work) synchronize_srcu(&unwind_srcu); - guard(rcu)(); /* Clear this bit from all threads */ - for_each_process_thread(g, t) { + for_each_process_thread_rcu(g, t) { atomic_long_andnot(BIT(bit), &t->unwind_info.unwind_mask); if (t->unwind_info.cache) -- 2.25.1
