mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
c360192bf4
Convert s390 to use a field in the struct lowcore for the CPU preemption count. It is a bit cheaper to access a lowcore field compared to a thread_info variable and it removes the depencency on a task related structure. bloat-o-meter on the vmlinux image for the default configuration (CONFIG_PREEMPT_NONE=y) reports a small reduction in text size: add/remove: 0/0 grow/shrink: 18/578 up/down: 228/-5448 (-5220) A larger improvement is achieved with the default configuration but with CONFIG_PREEMPT=y and CONFIG_DEBUG_PREEMPT=n: add/remove: 2/6 grow/shrink: 59/4477 up/down: 1618/-228762 (-227144) Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
138 lines
3.0 KiB
C
138 lines
3.0 KiB
C
#ifndef __ASM_PREEMPT_H
|
|
#define __ASM_PREEMPT_H
|
|
|
|
#include <asm/current.h>
|
|
#include <linux/thread_info.h>
|
|
#include <asm/atomic_ops.h>
|
|
|
|
#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
|
|
|
|
#define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED)
|
|
|
|
static inline int preempt_count(void)
|
|
{
|
|
return READ_ONCE(S390_lowcore.preempt_count) & ~PREEMPT_NEED_RESCHED;
|
|
}
|
|
|
|
static inline void preempt_count_set(int pc)
|
|
{
|
|
int old, new;
|
|
|
|
do {
|
|
old = READ_ONCE(S390_lowcore.preempt_count);
|
|
new = (old & PREEMPT_NEED_RESCHED) |
|
|
(pc & ~PREEMPT_NEED_RESCHED);
|
|
} while (__atomic_cmpxchg(&S390_lowcore.preempt_count,
|
|
old, new) != old);
|
|
}
|
|
|
|
#define init_task_preempt_count(p) do { } while (0)
|
|
|
|
#define init_idle_preempt_count(p, cpu) do { \
|
|
S390_lowcore.preempt_count = PREEMPT_ENABLED; \
|
|
} while (0)
|
|
|
|
static inline void set_preempt_need_resched(void)
|
|
{
|
|
__atomic_and(~PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
|
|
}
|
|
|
|
static inline void clear_preempt_need_resched(void)
|
|
{
|
|
__atomic_or(PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
|
|
}
|
|
|
|
static inline bool test_preempt_need_resched(void)
|
|
{
|
|
return !(READ_ONCE(S390_lowcore.preempt_count) & PREEMPT_NEED_RESCHED);
|
|
}
|
|
|
|
static inline void __preempt_count_add(int val)
|
|
{
|
|
if (__builtin_constant_p(val) && (val >= -128) && (val <= 127))
|
|
__atomic_add_const(val, &S390_lowcore.preempt_count);
|
|
else
|
|
__atomic_add(val, &S390_lowcore.preempt_count);
|
|
}
|
|
|
|
static inline void __preempt_count_sub(int val)
|
|
{
|
|
__preempt_count_add(-val);
|
|
}
|
|
|
|
static inline bool __preempt_count_dec_and_test(void)
|
|
{
|
|
return __atomic_add(-1, &S390_lowcore.preempt_count) == 1;
|
|
}
|
|
|
|
static inline bool should_resched(int preempt_offset)
|
|
{
|
|
return unlikely(READ_ONCE(S390_lowcore.preempt_count) ==
|
|
preempt_offset);
|
|
}
|
|
|
|
#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
|
|
|
|
#define PREEMPT_ENABLED (0)
|
|
|
|
static inline int preempt_count(void)
|
|
{
|
|
return READ_ONCE(S390_lowcore.preempt_count);
|
|
}
|
|
|
|
static inline void preempt_count_set(int pc)
|
|
{
|
|
S390_lowcore.preempt_count = pc;
|
|
}
|
|
|
|
#define init_task_preempt_count(p) do { } while (0)
|
|
|
|
#define init_idle_preempt_count(p, cpu) do { \
|
|
S390_lowcore.preempt_count = PREEMPT_ENABLED; \
|
|
} while (0)
|
|
|
|
static inline void set_preempt_need_resched(void)
|
|
{
|
|
}
|
|
|
|
static inline void clear_preempt_need_resched(void)
|
|
{
|
|
}
|
|
|
|
static inline bool test_preempt_need_resched(void)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline void __preempt_count_add(int val)
|
|
{
|
|
S390_lowcore.preempt_count += val;
|
|
}
|
|
|
|
static inline void __preempt_count_sub(int val)
|
|
{
|
|
S390_lowcore.preempt_count -= val;
|
|
}
|
|
|
|
static inline bool __preempt_count_dec_and_test(void)
|
|
{
|
|
return !--S390_lowcore.preempt_count && tif_need_resched();
|
|
}
|
|
|
|
static inline bool should_resched(int preempt_offset)
|
|
{
|
|
return unlikely(preempt_count() == preempt_offset &&
|
|
tif_need_resched());
|
|
}
|
|
|
|
#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
extern asmlinkage void preempt_schedule(void);
|
|
#define __preempt_schedule() preempt_schedule()
|
|
extern asmlinkage void preempt_schedule_notrace(void);
|
|
#define __preempt_schedule_notrace() preempt_schedule_notrace()
|
|
#endif /* CONFIG_PREEMPT */
|
|
|
|
#endif /* __ASM_PREEMPT_H */
|