Commit 50612a26 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Zeng Heng
Browse files

cpumask: Introduce DYING mask 

mainline inclusion
from mainline-v5.13-rc1
commit e40f74c5
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6VS35

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e40f74c535b8a0ecf3ef0388b51a34cdadb34fb5



--------------------------------

Introduce a cpumask that indicates (for each CPU) what direction the
CPU hotplug is currently going. Notably, it tracks rollbacks. Eg. when
an up fails and we do a roll-back down, it will accurately reflect the
direction.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210310150109.151441252@infradead.org


Signed-off-by: default avatarZeng Heng <zengheng4@huawei.com>
parent de2a0c7f

include/linux/cpumask.h

+19 −0
Original line number Diff line number Diff line
@@ -91,10 +91,12 @@ extern struct cpumask __cpu_possible_mask; 
extern struct cpumask __cpu_online_mask;

extern struct cpumask __cpu_present_mask;

extern struct cpumask __cpu_active_mask;

extern struct cpumask __cpu_dying_mask;

#define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask)

#define cpu_online_mask   ((const struct cpumask *)&__cpu_online_mask)

#define cpu_present_mask  ((const struct cpumask *)&__cpu_present_mask)

#define cpu_active_mask   ((const struct cpumask *)&__cpu_active_mask)

#define cpu_dying_mask    ((const struct cpumask *)&__cpu_dying_mask)



extern atomic_t __num_online_cpus;
@@ -118,6 +120,11 @@ static inline unsigned int num_online_cpus(void) 
#define cpu_possible(cpu)	cpumask_test_cpu((cpu), cpu_possible_mask)

#define cpu_present(cpu)	cpumask_test_cpu((cpu), cpu_present_mask)

#define cpu_active(cpu)		cpumask_test_cpu((cpu), cpu_active_mask)

static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask);

static inline bool cpu_dying(unsigned int cpu)

{

	return cpumask_test_cpu(cpu, cpu_dying_mask);

}

#else

#define num_online_cpus()	1U

#define num_possible_cpus()	1U
@@ -127,6 +134,10 @@ static inline unsigned int num_online_cpus(void) 
#define cpu_possible(cpu)	((cpu) == 0)

#define cpu_present(cpu)	((cpu) == 0)

#define cpu_active(cpu)		((cpu) == 0)

static inline bool cpu_dying(unsigned int cpu)

{

	return false;

}

#endif



extern cpumask_t cpus_booted_once_mask;
@@ -851,6 +862,14 @@ set_cpu_active(unsigned int cpu, bool active) 
		cpumask_clear_cpu(cpu, &__cpu_active_mask);

}



static inline void

set_cpu_dying(unsigned int cpu, bool dying)

{

	if (dying)

		cpumask_set_cpu(cpu, &__cpu_dying_mask);

	else

		cpumask_clear_cpu(cpu, &__cpu_dying_mask);

}



/**

 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *

kernel/cpu.c

+6 −0
Original line number Diff line number Diff line
@@ -157,6 +157,9 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, 
	int (*cb)(unsigned int cpu);

	int ret, cnt;



	if (cpu_dying(cpu) != !bringup)

		set_cpu_dying(cpu, !bringup);



	if (st->fail == state) {

		st->fail = CPUHP_INVALID;
@@ -2502,6 +2505,9 @@ EXPORT_SYMBOL(__cpu_present_mask); 
struct cpumask __cpu_active_mask __read_mostly;

EXPORT_SYMBOL(__cpu_active_mask);



struct cpumask __cpu_dying_mask __read_mostly;

EXPORT_SYMBOL(__cpu_dying_mask);



atomic_t __num_online_cpus __read_mostly;

EXPORT_SYMBOL(__num_online_cpus);