diff options
| -rw-r--r-- | arch/arm/include/asm/unistd.h | 2 | ||||
| -rw-r--r-- | arch/arm/include/uapi/asm/unistd.h | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/calls.S | 2 | ||||
| -rw-r--r-- | arch/x86/syscalls/syscall_32.tbl | 2 | ||||
| -rw-r--r-- | arch/x86/syscalls/syscall_64.tbl | 2 | ||||
| -rw-r--r-- | include/linux/sched.h | 62 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 6 | ||||
| -rw-r--r-- | kernel/sched/core.c | 263 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 9 |
9 files changed, 326 insertions, 24 deletions
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h index 141baa3f9a72..acabef1a75df 100644 --- a/arch/arm/include/asm/unistd.h +++ b/arch/arm/include/asm/unistd.h @@ -15,7 +15,7 @@ #include <uapi/asm/unistd.h> -#define __NR_syscalls (380) +#define __NR_syscalls (384) #define __ARM_NR_cmpxchg (__ARM_NR_BASE+0x00fff0) #define __ARCH_WANT_STAT64 diff --git a/arch/arm/include/uapi/asm/unistd.h b/arch/arm/include/uapi/asm/unistd.h index af33b44990ed..fb5584d0cc05 100644 --- a/arch/arm/include/uapi/asm/unistd.h +++ b/arch/arm/include/uapi/asm/unistd.h @@ -406,6 +406,8 @@ #define __NR_process_vm_writev (__NR_SYSCALL_BASE+377) #define __NR_kcmp (__NR_SYSCALL_BASE+378) #define __NR_finit_module (__NR_SYSCALL_BASE+379) +#define __NR_sched_setattr (__NR_SYSCALL_BASE+380) +#define __NR_sched_getattr (__NR_SYSCALL_BASE+381) /* * This may need to be greater than __NR_last_syscall+1 in order to diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index c6ca7e376773..166e945de832 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -389,6 +389,8 @@ CALL(sys_process_vm_writev) CALL(sys_kcmp) CALL(sys_finit_module) +/* 380 */ CALL(sys_sched_setattr) + CALL(sys_sched_getattr) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls #define syscalls_counted diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl index aabfb8380a1c..96bc506ac6de 100644 --- a/arch/x86/syscalls/syscall_32.tbl +++ b/arch/x86/syscalls/syscall_32.tbl @@ -357,3 +357,5 @@ 348 i386 process_vm_writev sys_process_vm_writev compat_sys_process_vm_writev 349 i386 kcmp sys_kcmp 350 i386 finit_module sys_finit_module +351 i386 sched_setattr sys_sched_setattr +352 i386 sched_getattr sys_sched_getattr diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl index 38ae65dfd14f..a12bddc7ccea 100644 --- a/arch/x86/syscalls/syscall_64.tbl +++ b/arch/x86/syscalls/syscall_64.tbl @@ -320,6 +320,8 @@ 311 64 process_vm_writev sys_process_vm_writev 312 common kcmp sys_kcmp 313 common finit_module sys_finit_module +314 common sched_setattr sys_sched_setattr +315 common sched_getattr sys_sched_getattr # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/include/linux/sched.h b/include/linux/sched.h index 3a1e9857b393..86025b6c6387 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -56,6 +56,66 @@ struct sched_param { #include <asm/processor.h> +#define SCHED_ATTR_SIZE_VER0 48 /* sizeof first published struct */ + +/* + * Extended scheduling parameters data structure. + * + * This is needed because the original struct sched_param can not be + * altered without introducing ABI issues with legacy applications + * (e.g., in sched_getparam()). + * + * However, the possibility of specifying more than just a priority for + * the tasks may be useful for a wide variety of application fields, e.g., + * multimedia, streaming, automation and control, and many others. + * + * This variant (sched_attr) is meant at describing a so-called + * sporadic time-constrained task. In such model a task is specified by: + * - the activation period or minimum instance inter-arrival time; + * - the maximum (or average, depending on the actual scheduling + * discipline) computation time of all instances, a.k.a. runtime; + * - the deadline (relative to the actual activation time) of each + * instance. + * Very briefly, a periodic (sporadic) task asks for the execution of + * some specific computation --which is typically called an instance-- + * (at most) every period. Moreover, each instance typically lasts no more + * than the runtime and must be completed by time instant t equal to + * the instance activation time + the deadline. + * + * This is reflected by the actual fields of the sched_attr structure: + * + * @size size of the structure, for fwd/bwd compat. + * + * @sched_policy task's scheduling policy + * @sched_flags for customizing the scheduler behaviour + * @sched_nice task's nice value (SCHED_NORMAL/BATCH) + * @sched_priority task's static priority (SCHED_FIFO/RR) + * @sched_deadline representative of the task's deadline + * @sched_runtime representative of the task's runtime + * @sched_period representative of the task's period + * + * Given this task model, there are a multiplicity of scheduling algorithms + * and policies, that can be used to ensure all the tasks will make their + * timing constraints. + */ +struct sched_attr { + u32 size; + + u32 sched_policy; + u64 sched_flags; + + /* SCHED_NORMAL, SCHED_BATCH */ + s32 sched_nice; + + /* SCHED_FIFO, SCHED_RR */ + u32 sched_priority; + + /* SCHED_DEADLINE */ + u64 sched_runtime; + u64 sched_deadline; + u64 sched_period; +}; + struct exec_domain; struct futex_pi_state; struct robust_list_head; @@ -1958,6 +2018,8 @@ extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); +extern int sched_setattr(struct task_struct *, + const struct sched_attr *); extern struct task_struct *idle_task(int cpu); /** * is_idle_task - is the specified task an idle task? diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 94273bbe6050..40ed9e9a77e5 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -38,6 +38,7 @@ struct rlimit; struct rlimit64; struct rusage; struct sched_param; +struct sched_attr; struct sel_arg_struct; struct semaphore; struct sembuf; @@ -279,9 +280,14 @@ asmlinkage long sys_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param); asmlinkage long sys_sched_setparam(pid_t pid, struct sched_param __user *param); +asmlinkage long sys_sched_setattr(pid_t pid, + struct sched_attr __user *attr); asmlinkage long sys_sched_getscheduler(pid_t pid); asmlinkage long sys_sched_getparam(pid_t pid, struct sched_param __user *param); +asmlinkage long sys_sched_getattr(pid_t pid, + struct sched_attr __user *attr, + unsigned int size); asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long __user *user_mask_ptr); asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len, diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b21a63ed5d62..8174f889076c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2817,6 +2817,7 @@ out_unlock: __task_rq_unlock(rq); } #endif + void set_user_nice(struct task_struct *p, long nice) { int old_prio, delta, on_rq; @@ -2991,22 +2992,29 @@ static struct task_struct *find_process_by_pid(pid_t pid) return pid ? find_task_by_vpid(pid) : current; } -/* Actually do priority change: must hold rq lock. */ -static void -__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) +/* Actually do priority change: must hold pi & rq lock. */ +static void __setscheduler(struct rq *rq, struct task_struct *p, + const struct sched_attr *attr) { + int policy = attr->sched_policy; + p->policy = policy; - p->rt_priority = prio; + + if (rt_policy(policy)) + p->rt_priority = attr->sched_priority; + else + p->static_prio = NICE_TO_PRIO(attr->sched_nice); + p->normal_prio = normal_prio(p); - /* we are holding p->pi_lock already */ p->prio = rt_mutex_getprio(p); + if (rt_prio(p->prio)) p->sched_class = &rt_sched_class; else p->sched_class = &fair_sched_class; + set_load_weight(p); } - /* * check the target process has a UID that matches the current process's */ @@ -3023,10 +3031,12 @@ static bool check_same_owner(struct task_struct *p) return match; } -static int __sched_setscheduler(struct task_struct *p, int policy, - const struct sched_param *param, bool user) +static int __sched_setscheduler(struct task_struct *p, + const struct sched_attr *attr, + bool user) { int retval, oldprio, oldpolicy = -1, on_rq, running; + int policy = attr->sched_policy; unsigned long flags; const struct sched_class *prev_class; struct rq *rq; @@ -3054,17 +3064,22 @@ recheck: * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, * SCHED_BATCH and SCHED_IDLE is 0. */ - if (param->sched_priority < 0 || - (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || - (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) + if (attr->sched_priority < 0 || + (p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) || + (!p->mm && attr->sched_priority > MAX_RT_PRIO-1)) return -EINVAL; - if (rt_policy(policy) != (param->sched_priority != 0)) + if (rt_policy(policy) != (attr->sched_priority != 0)) return -EINVAL; /* * Allow unprivileged RT tasks to decrease priority: */ if (user && !capable(CAP_SYS_NICE)) { + if (fair_policy(policy)) { + if (!can_nice(p, attr->sched_nice)) + return -EPERM; + } + if (rt_policy(policy)) { unsigned long rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); @@ -3074,8 +3089,8 @@ recheck: return -EPERM; /* can't increase priority */ - if (param->sched_priority > p->rt_priority && - param->sched_priority > rlim_rtprio) + if (attr->sched_priority > p->rt_priority && + attr->sched_priority > rlim_rtprio) return -EPERM; } @@ -3123,11 +3138,16 @@ recheck: /* * If not changing anything there's no need to proceed further: */ - if (unlikely(policy == p->policy && (!rt_policy(policy) || - param->sched_priority == p->rt_priority))) { + if (unlikely(policy == p->policy)) { + if (fair_policy(policy) && attr->sched_nice != TASK_NICE(p)) + goto change; + if (rt_policy(policy) && attr->sched_priority != p->rt_priority) + goto change; + task_rq_unlock(rq, p, &flags); return 0; } +change: #ifdef CONFIG_RT_GROUP_SCHED if (user) { @@ -3161,7 +3181,7 @@ recheck: oldprio = p->prio; prev_class = p->sched_class; - __setscheduler(rq, p, policy, param->sched_priority); + __setscheduler(rq, p, attr); if (running) p->sched_class->set_curr_task(rq); @@ -3189,10 +3209,20 @@ recheck: int sched_setscheduler(struct task_struct *p, int policy, const struct sched_param *param) { - return __sched_setscheduler(p, policy, param, true); + struct sched_attr attr = { + .sched_policy = policy, + .sched_priority = param->sched_priority + }; + return __sched_setscheduler(p, &attr, true); } EXPORT_SYMBOL_GPL(sched_setscheduler); +int sched_setattr(struct task_struct *p, const struct sched_attr *attr) +{ + return __sched_setscheduler(p, attr, true); +} +EXPORT_SYMBOL_GPL(sched_setattr); + /** * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. * @p: the task in question. @@ -3209,7 +3239,11 @@ EXPORT_SYMBOL_GPL(sched_setscheduler); int sched_setscheduler_nocheck(struct task_struct *p, int policy, const struct sched_param *param) { - return __sched_setscheduler(p, policy, param, false); + struct sched_attr attr = { + .sched_policy = policy, + .sched_priority = param->sched_priority + }; + return __sched_setscheduler(p, &attr, false); } static int @@ -3234,6 +3268,79 @@ do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) return retval; } +/* + * Mimics kernel/events/core.c perf_copy_attr(). + */ +static int sched_copy_attr(struct sched_attr __user *uattr, + struct sched_attr *attr) +{ + u32 size; + int ret; + + if (!access_ok(VERIFY_WRITE, uattr, SCHED_ATTR_SIZE_VER0)) + return -EFAULT; + + /* + * zero the full structure, so that a short copy will be nice. + */ + memset(attr, 0, sizeof(*attr)); + + ret = get_user(size, &uattr->size); + if (ret) + return ret; + + if (size > PAGE_SIZE) /* silly large */ + goto err_size; + + if (!size) /* abi compat */ + size = SCHED_ATTR_SIZE_VER0; + + if (size < SCHED_ATTR_SIZE_VER0) + goto err_size; + + /* + * If we're handed a bigger struct than we know of, + * ensure all the unknown bits are 0 - i.e. new + * user-space does not rely on any kernel feature + * extensions we dont know about yet. + */ + if (size > sizeof(*attr)) { + unsigned char __user *addr; + unsigned char __user *end; + unsigned char val; + + addr = (void __user *)uattr + sizeof(*attr); + end = (void __user *)uattr + size; + + for (; addr < end; addr++) { + ret = get_user(val, addr); + if (ret) + return ret; + if (val) + goto err_size; + } + size = sizeof(*attr); + } + + ret = copy_from_user(attr, uattr, size); + if (ret) + return -EFAULT; + + /* + * XXX: do we want to be lenient like existing syscalls; or do we want + * to be strict and return an error on out-of-bounds values? + */ + attr->sched_nice = clamp(attr->sched_nice, -20, 19); + +out: + return ret; + +err_size: + put_user(sizeof(*attr), &uattr->size); + ret = -E2BIG; + goto out; +} + /** * sys_sched_setscheduler - set/change the scheduler policy and RT priority * @pid: the pid in question. @@ -3265,6 +3372,33 @@ SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) } /** + * sys_sched_setattr - same as above, but with extended sched_attr + * @pid: the pid in question. + * @attr: structure containing the extended parameters. + */ +SYSCALL_DEFINE2(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr) +{ + struct sched_attr attr; + struct task_struct *p; + int retval; + + if (!uattr || pid < 0) + return -EINVAL; + + if (sched_copy_attr(uattr, &attr)) + return -EFAULT; + + rcu_read_lock(); + retval = -ESRCH; + p = find_process_by_pid(pid); + if (p != NULL) + retval = sched_setattr(p, &attr); + rcu_read_unlock(); + + return retval; +} + +/** * sys_sched_getscheduler - get the policy (scheduling class) of a thread * @pid: the pid in question. * @@ -3334,6 +3468,92 @@ out_unlock: return retval; } +static int sched_read_attr(struct sched_attr __user *uattr, + struct sched_attr *attr, + unsigned int usize) +{ + int ret; + + if (!access_ok(VERIFY_WRITE, uattr, usize)) + return -EFAULT; + + /* + * If we're handed a smaller struct than we know of, + * ensure all the unknown bits are 0 - i.e. old + * user-space does not get uncomplete information. + */ + if (usize < sizeof(*attr)) { + unsigned char *addr; + unsigned char *end; + + addr = (void *)attr + usize; + end = (void *)attr + sizeof(*attr); + + for (; addr < end; addr++) { + if (*addr) + goto err_size; + } + + attr->size = usize; + } + + ret = copy_to_user(uattr, attr, usize); + if (ret) + return -EFAULT; + +out: + return ret; + +err_size: + ret = -E2BIG; + goto out; +} + +/** + * sys_sched_getattr - same as above, but with extended "sched_param" + * @pid: the pid in question. + * @attr: structure containing the extended parameters. + * @size: sizeof(attr) for fwd/bwd comp. + */ +SYSCALL_DEFINE3(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, + unsigned int, size) +{ + struct sched_attr attr = { + .size = sizeof(struct sched_attr), + }; + struct task_struct *p; + int retval; + + if (!uattr || pid < 0 || size > PAGE_SIZE || + size < SCHED_ATTR_SIZE_VER0) + return -EINVAL; + + rcu_read_lock(); + p = find_process_by_pid(pid); + retval = -ESRCH; + if (!p) + goto out_unlock; + + retval = security_task_getscheduler(p); + if (retval) + goto out_unlock; + + attr.sched_policy = p->policy; + if (task_has_rt_policy(p)) + attr.sched_priority = p->rt_priority; + else + attr.sched_nice = TASK_NICE(p); + + rcu_read_unlock(); + + retval = sched_read_attr(uattr, &attr, size); + return retval; + +out_unlock: + rcu_read_unlock(); + return retval; +} + long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) { cpumask_var_t cpus_allowed, new_mask; @@ -6400,13 +6620,16 @@ EXPORT_SYMBOL(__might_sleep); static void normalize_task(struct rq *rq, struct task_struct *p) { const struct sched_class *prev_class = p->sched_class; + struct sched_attr attr = { + .sched_policy = SCHED_NORMAL, + }; int old_prio = p->prio; int on_rq; on_rq = p->on_rq; if (on_rq) dequeue_task(rq, p, 0); - __setscheduler(rq, p, SCHED_NORMAL, 0); + __setscheduler(rq, p, &attr); if (on_rq) { enqueue_task(rq, p, 0); resched_task(rq->curr); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index b3b4a4953efc..df023db7721c 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -81,11 +81,14 @@ extern void update_cpu_load_active(struct rq *this_rq); */ #define RUNTIME_INF ((u64)~0ULL) +static inline int fair_policy(int policy) +{ + return policy == SCHED_NORMAL || policy == SCHED_BATCH; +} + static inline int rt_policy(int policy) { - if (policy == SCHED_FIFO || policy == SCHED_RR) - return 1; - return 0; + return policy == SCHED_FIFO || policy == SCHED_RR; } static inline int task_has_rt_policy(struct task_struct *p) |