From aa6da5140b784ece799f670bf532096f67aa7785 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 21 Oct 2014 13:23:08 -0700 Subject: [PATCH] rcu: Remove "cpu" argument to rcu_needs_cpu() The "cpu" argument to rcu_needs_cpu() is always the current CPU, so drop it. This in turn allows the "cpu" argument to rcu_cpu_has_callbacks() to be removed, which allows the uses of "cpu" in both functions to be replaced with a this_cpu_ptr(). Again, the anticipated cross-CPU uses of these functions has been replaced by NO_HZ_FULL. Signed-off-by: Paul E. McKenney Reviewed-by: Pranith Kumar --- include/linux/rcupdate.h | 2 +- include/linux/rcutree.h | 2 +- kernel/rcu/tree.c | 4 ++-- kernel/rcu/tree_plugin.h | 12 ++++++------ kernel/time/tick-sched.c | 2 +- 5 files changed, 11 insertions(+), 11 deletions(-) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index b4ad275d90d0..4eb810832b19 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -1103,7 +1103,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) #if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL) -static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) +static inline int rcu_needs_cpu(unsigned long *delta_jiffies) { *delta_jiffies = ULONG_MAX; return 0; diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 7b5484db1857..52953790dcca 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -32,7 +32,7 @@ void rcu_note_context_switch(void); #ifndef CONFIG_RCU_NOCB_CPU_ALL -int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies); +int rcu_needs_cpu(unsigned long *delta_jiffies); #endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ void rcu_cpu_stall_reset(void); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index b591f1459240..d678a98caf1d 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3159,7 +3159,7 @@ static int rcu_pending(void) * non-NULL, store an indication of whether all callbacks are lazy. * (If there are no callbacks, all of them are deemed to be lazy.) */ -static int __maybe_unused rcu_cpu_has_callbacks(int cpu, bool *all_lazy) +static int __maybe_unused rcu_cpu_has_callbacks(bool *all_lazy) { bool al = true; bool hc = false; @@ -3167,7 +3167,7 @@ static int __maybe_unused rcu_cpu_has_callbacks(int cpu, bool *all_lazy) struct rcu_state *rsp; for_each_rcu_flavor(rsp) { - rdp = per_cpu_ptr(rsp->rda, cpu); + rdp = this_cpu_ptr(rsp->rda); if (!rdp->nxtlist) continue; hc = true; diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 495d4cce47a7..1797b76cb3ff 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1512,10 +1512,10 @@ static void rcu_prepare_kthreads(int cpu) * any flavor of RCU. */ #ifndef CONFIG_RCU_NOCB_CPU_ALL -int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) +int rcu_needs_cpu(unsigned long *delta_jiffies) { *delta_jiffies = ULONG_MAX; - return rcu_cpu_has_callbacks(cpu, NULL); + return rcu_cpu_has_callbacks(NULL); } #endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ @@ -1624,15 +1624,15 @@ static bool __maybe_unused rcu_try_advance_all_cbs(void) * The caller must have disabled interrupts. */ #ifndef CONFIG_RCU_NOCB_CPU_ALL -int rcu_needs_cpu(int cpu, unsigned long *dj) +int rcu_needs_cpu(unsigned long *dj) { - struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); + struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); /* Snapshot to detect later posting of non-lazy callback. */ rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted; /* If no callbacks, RCU doesn't need the CPU. */ - if (!rcu_cpu_has_callbacks(cpu, &rdtp->all_lazy)) { + if (!rcu_cpu_has_callbacks(&rdtp->all_lazy)) { *dj = ULONG_MAX; return 0; } @@ -1679,7 +1679,7 @@ static void rcu_prepare_for_idle(int cpu) /* Handle nohz enablement switches conservatively. */ tne = ACCESS_ONCE(tick_nohz_active); if (tne != rdtp->tick_nohz_enabled_snap) { - if (rcu_cpu_has_callbacks(cpu, NULL)) + if (rcu_cpu_has_callbacks(NULL)) invoke_rcu_core(); /* force nohz to see update. */ rdtp->tick_nohz_enabled_snap = tne; return; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 7b5741fc4110..1f4356037a7d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -585,7 +585,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, last_jiffies = jiffies; } while (read_seqretry(&jiffies_lock, seq)); - if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || + if (rcu_needs_cpu(&rcu_delta_jiffies) || arch_needs_cpu() || irq_work_needs_cpu()) { next_jiffies = last_jiffies + 1; delta_jiffies = 1; -- 2.39.5