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authorDario Faggioli <raistlin@linux.it>2013-11-07 14:43:36 +0100
committerIngo Molnar <mingo@kernel.org>2014-01-13 13:41:04 +0100
commitd50dde5a10f305253cbc3855307f608f8a3c5f73 (patch)
tree940022e0216611f198d9a00f1cb3bfc59b2014d8 /kernel/sched/sched.h
parentMerge branch 'sched/urgent' into sched/core (diff)
downloadlinux-d50dde5a10f305253cbc3855307f608f8a3c5f73.tar.xz
linux-d50dde5a10f305253cbc3855307f608f8a3c5f73.zip
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 <raistlin@linux.it> [ Rewrote to use sched_attr. ] Signed-off-by: Juri Lelli <juri.lelli@gmail.com> [ Removed sched_setscheduler2() for now. ] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-3-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/sched.h')
-rw-r--r--kernel/sched/sched.h9
1 files changed, 6 insertions, 3 deletions
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)