From 29b72bdb8b659a853436b3f22875131678486ce7 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 4 Sep 2019 16:55:27 +0200 Subject: [PATCH 296/338] hrtimer: Add a missing bracket and hide `migration_base' on !SMP Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.193-rt81.tar.xz [ Upstream commit 47b6de0b7f22c28b40275aeede3993d807668c3b ] [ Upstream commit 5d2295f3a93b04986d069ebeaf5b07725f9096c1 ] The recent change to avoid taking the expiry lock when a timer is currently migrated missed to add a bracket at the end of the if statement leading to compile errors. Since that commit the variable `migration_base' is always used but it is only available on SMP configuration thus leading to another compile error. The changelog says "The timer base and base->cpu_base cannot be NULL in the code path", so it is safe to limit this check to SMP configurations only. Add the missing bracket to the if statement and hide `migration_base' behind CONFIG_SMP bars. [ tglx: Mark the functions inline ... ] Fixes: 68b2c8c1e4210 ("hrtimer: Don't take expiry_lock when timer is currently migrated") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190904145527.eah7z56ntwobqm6j@linutronix.de Signed-off-by: Steven Rostedt (VMware) [bigeasy: port back to RT] Signed-off-by: Sebastian Andrzej Siewior --- kernel/time/hrtimer.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index eac98cfec814..cd76cd3444e7 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -150,6 +150,11 @@ static struct hrtimer_cpu_base migration_cpu_base = { #define migration_base migration_cpu_base.clock_base[0] +static inline bool is_migration_base(struct hrtimer_clock_base *base) +{ + return base == &migration_base; +} + /* * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock * means that all timers which are tied to this base via timer->base are @@ -274,6 +279,11 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, #else /* CONFIG_SMP */ +static inline bool is_migration_base(struct hrtimer_clock_base *base) +{ + return false; +} + static inline struct hrtimer_clock_base * lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) { @@ -961,7 +971,7 @@ void hrtimer_grab_expiry_lock(const struct hrtimer *timer) { struct hrtimer_clock_base *base = READ_ONCE(timer->base); - if (timer->is_soft && base != &migration_base) { + if (timer->is_soft && is_migration_base(base)) { spin_lock(&base->cpu_base->softirq_expiry_lock); spin_unlock(&base->cpu_base->softirq_expiry_lock); } -- 2.31.1