From d50dde5a10f305253cbc3855307f608f8a3c5f73 Mon Sep 17 00:00:00 2001 From: Dario Faggioli Date: Thu, 7 Nov 2013 14:43:36 +0100 Subject: sched: Add new scheduler syscalls to support an extended scheduling parameters ABI Add the syscalls needed for supporting scheduling algorithms with extended scheduling parameters (e.g., SCHED_DEADLINE). In general, it makes possible to specify a periodic/sporadic task, that executes for a given amount of runtime at each instance, and is scheduled according to the urgency of their own timing constraints, i.e.: - a (maximum/typical) instance execution time, - a minimum interval between consecutive instances, - a time constraint by which each instance must be completed. Thus, both the data structure that holds the scheduling parameters of the tasks and the system calls dealing with it must be extended. Unfortunately, modifying the existing struct sched_param would break the ABI and result in potentially serious compatibility issues with legacy binaries. For these reasons, this patch: - defines the new struct sched_attr, containing all the fields that are necessary for specifying a task in the computational model described above; - defines and implements the new scheduling related syscalls that manipulate it, i.e., sched_setattr() and sched_getattr(). Syscalls are introduced for x86 (32 and 64 bits) and ARM only, as a proof of concept and for developing and testing purposes. Making them available on other architectures is straightforward. Since no "user" for these new parameters is introduced in this patch, the implementation of the new system calls is just identical to their already existing counterpart. Future patches that implement scheduling policies able to exploit the new data structure must also take care of modifying the sched_*attr() calls accordingly with their own purposes. Signed-off-by: Dario Faggioli [ Rewrote to use sched_attr. ] Signed-off-by: Juri Lelli [ Removed sched_setscheduler2() for now. ] Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1383831828-15501-3-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar --- include/linux/syscalls.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/syscalls.h') 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, -- cgit v1.2.2