If the user wants to stop controlling uclamp and let the task inherit the value from the group, we need a method to reset.
Add SCHED_FLAG_UTIL_CLAMP_RESET flag to allow the user to reset uclamp via sched_setattr syscall. Signed-off-by: Yun Hsiang <[email protected]> --- include/uapi/linux/sched.h | 9 ++++++++- kernel/sched/core.c | 16 ++++++++++++---- 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h index 3bac0a8ceab2..a12e88c362d8 100644 --- a/include/uapi/linux/sched.h +++ b/include/uapi/linux/sched.h @@ -132,6 +132,9 @@ struct clone_args { #define SCHED_FLAG_KEEP_PARAMS 0x10 #define SCHED_FLAG_UTIL_CLAMP_MIN 0x20 #define SCHED_FLAG_UTIL_CLAMP_MAX 0x40 +#define SCHED_FLAG_UTIL_CLAMP_RESET_MIN 0x80 +#define SCHED_FLAG_UTIL_CLAMP_RESET_MAX 0x100 + #define SCHED_FLAG_KEEP_ALL (SCHED_FLAG_KEEP_POLICY | \ SCHED_FLAG_KEEP_PARAMS) @@ -139,10 +142,14 @@ struct clone_args { #define SCHED_FLAG_UTIL_CLAMP (SCHED_FLAG_UTIL_CLAMP_MIN | \ SCHED_FLAG_UTIL_CLAMP_MAX) +#define SCHED_FLAG_UTIL_CLAMP_RESET (SCHED_FLAG_UTIL_CLAMP_RESET_MIN | \ + SCHED_FLAG_UTIL_CLAMP_RESET_MAX) + #define SCHED_FLAG_ALL (SCHED_FLAG_RESET_ON_FORK | \ SCHED_FLAG_RECLAIM | \ SCHED_FLAG_DL_OVERRUN | \ SCHED_FLAG_KEEP_ALL | \ - SCHED_FLAG_UTIL_CLAMP) + SCHED_FLAG_UTIL_CLAMP | \ + SCHED_FLAG_UTIL_CLAMP_RESET) #endif /* _UAPI_LINUX_SCHED_H */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9a2fbf98fd6f..ed4cb412dde7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1207,15 +1207,22 @@ static void __setscheduler_uclamp(struct task_struct *p, uclamp_se_set(uc_se, clamp_value, false); } - if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP))) + if (likely(!(attr->sched_flags & + (SCHED_FLAG_UTIL_CLAMP | SCHED_FLAG_UTIL_CLAMP_RESET)))) return; - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_RESET_MIN) { + uclamp_se_set(&p->uclamp_req[UCLAMP_MIN], + 0, false); + } else if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { uclamp_se_set(&p->uclamp_req[UCLAMP_MIN], attr->sched_util_min, true); } - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_RESET_MAX) { + uclamp_se_set(&p->uclamp_req[UCLAMP_MAX], + 1024, false); + } else if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { uclamp_se_set(&p->uclamp_req[UCLAMP_MAX], attr->sched_util_max, true); } @@ -4901,7 +4908,8 @@ static int __sched_setscheduler(struct task_struct *p, goto change; if (dl_policy(policy) && dl_param_changed(p, attr)) goto change; - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) + if (attr->sched_flags & + (SCHED_FLAG_UTIL_CLAMP | SCHED_FLAG_UTIL_CLAMP_RESET)) goto change; p->sched_reset_on_fork = reset_on_fork; -- 2.25.1
