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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2019-06-08 12:13:57 +0200 |
|---|---|---|
| committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2019-06-15 12:25:55 +0200 |
| commit | 4ecf0a43e729a7e641d800c294faabe87378fc05 (patch) | |
| tree | d7c164a2215c69a17b319076b64dd99ea1f85351 | |
| parent | 38f2c691a4b3e89d476f8e8350d1ca299974b89d (diff) | |
| download | linux-stable-4ecf0a43e729a7e641d800c294faabe87378fc05.tar.gz | |
processor: get rid of cpu_relax_yield
stop_machine is the only user left of cpu_relax_yield. Given that it
now has special semantics which are tied to stop_machine introduce a
weak stop_machine_yield function which architectures can override, and
get rid of the generic cpu_relax_yield implementation.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/processor.h | 6 | ||||
| -rw-r--r-- | arch/s390/kernel/processor.c | 4 | ||||
| -rw-r--r-- | include/linux/sched.h | 4 | ||||
| -rw-r--r-- | include/linux/stop_machine.h | 1 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 7 |
5 files changed, 9 insertions, 13 deletions
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 445ce9ee4404..14883b1562e0 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -222,12 +222,6 @@ static __no_kasan_or_inline unsigned short stap(void) return cpu_address; } -/* - * Give up the time slice of the virtual PU. - */ -#define cpu_relax_yield cpu_relax_yield -void cpu_relax_yield(const struct cpumask *cpumask); - #define cpu_relax() barrier() #define ECAG_CACHE_ATTRIBUTE 0 diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c index 4cdaefec1b7c..6ebc2117c66c 100644 --- a/arch/s390/kernel/processor.c +++ b/arch/s390/kernel/processor.c @@ -7,6 +7,7 @@ #define KMSG_COMPONENT "cpu" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt +#include <linux/stop_machine.h> #include <linux/cpufeature.h> #include <linux/bitops.h> #include <linux/kernel.h> @@ -59,7 +60,7 @@ void s390_update_cpu_mhz(void) on_each_cpu(update_cpu_mhz, NULL, 0); } -void notrace cpu_relax_yield(const struct cpumask *cpumask) +void notrace stop_machine_yield(const struct cpumask *cpumask) { int cpu, this_cpu; @@ -73,7 +74,6 @@ void notrace cpu_relax_yield(const struct cpumask *cpumask) smp_yield_cpu(cpu); } } -EXPORT_SYMBOL(cpu_relax_yield); /* * cpu_init - initializes state that is per-CPU. diff --git a/include/linux/sched.h b/include/linux/sched.h index 1f9f3160da7e..911675416b05 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1518,10 +1518,6 @@ static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpuma } #endif -#ifndef cpu_relax_yield -#define cpu_relax_yield(cpumask) cpu_relax() -#endif - extern int yield_to(struct task_struct *p, bool preempt); extern void set_user_nice(struct task_struct *p, long nice); extern int task_prio(const struct task_struct *p); diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 6d3635c86dbe..f9a0c6189852 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -36,6 +36,7 @@ int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); void stop_machine_park(int cpu); void stop_machine_unpark(int cpu); +void stop_machine_yield(const struct cpumask *cpumask); #else /* CONFIG_SMP */ diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index b8b0c5ff8da9..b4f83f7bdf86 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -177,6 +177,11 @@ static void ack_state(struct multi_stop_data *msdata) set_state(msdata, msdata->state + 1); } +void __weak stop_machine_yield(const struct cpumask *cpumask) +{ + cpu_relax(); +} + /* This is the cpu_stop function which stops the CPU. */ static int multi_cpu_stop(void *data) { @@ -204,7 +209,7 @@ static int multi_cpu_stop(void *data) /* Simple state machine */ do { /* Chill out and ensure we re-read multi_stop_state. */ - cpu_relax_yield(cpumask); + stop_machine_yield(cpumask); if (msdata->state != curstate) { curstate = msdata->state; switch (curstate) { |