Re: [PATCH] sched: make policy-testing consistent in core

From: Henrik Austad
Date: Wed Sep 09 2015 - 05:32:58 EST


As per-irc request

*prod*

thanks!
-Henrik

On Thu, Aug 20, 2015 at 03:54:02PM +0200, Henrik Austad wrote:
> Most of the policy-tests are done via the <class>_policy() helpers with
> the notable exception of idle. A new wrapper for valid_policy() has also
> been added to improve readability in set_load_weight().
>
> This commit does not change the logical behavior of the scheduler core.
>
> Signed-off-by: Henrik Austad <henrik@xxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> CC: linux-kernel@xxxxxxxxxxxxxxx
> ---
> kernel/sched/core.c | 9 +++------
> kernel/sched/sched.h | 9 +++++++++
> 2 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 78b4bad10081..476a30e5632a 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -816,7 +816,7 @@ static void set_load_weight(struct task_struct *p)
> /*
> * SCHED_IDLE tasks get minimal weight:
> */
> - if (p->policy == SCHED_IDLE) {
> + if (idle_policy(p->policy)) {
> load->weight = scale_load(WEIGHT_IDLEPRIO);
> load->inv_weight = WMULT_IDLEPRIO;
> return;
> @@ -3684,10 +3684,7 @@ recheck:
> } else {
> reset_on_fork = !!(attr->sched_flags & SCHED_FLAG_RESET_ON_FORK);
>
> - if (policy != SCHED_DEADLINE &&
> - policy != SCHED_FIFO && policy != SCHED_RR &&
> - policy != SCHED_NORMAL && policy != SCHED_BATCH &&
> - policy != SCHED_IDLE)
> + if (!valid_policy(policy))
> return -EINVAL;
> }
>
> @@ -3743,7 +3740,7 @@ recheck:
> * Treat SCHED_IDLE as nice 20. Only allow a switch to
> * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
> */
> - if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) {
> + if (idle_policy(p->policy) && !idle_policy(policy)) {
> if (!can_nice(p, task_nice(p)))
> return -EPERM;
> }
> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index 84d48790bb6d..fe7cb34cc55b 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -84,6 +84,10 @@ static inline void update_cpu_load_active(struct rq *this_rq) { }
> */
> #define RUNTIME_INF ((u64)~0ULL)
>
> +static inline int idle_policy(int policy)
> +{
> + return policy == SCHED_IDLE;
> +}
> static inline int fair_policy(int policy)
> {
> return policy == SCHED_NORMAL || policy == SCHED_BATCH;
> @@ -98,6 +102,11 @@ static inline int dl_policy(int policy)
> {
> return policy == SCHED_DEADLINE;
> }
> +static inline bool valid_policy(int policy)
> +{
> + return idle_policy(policy) || fair_policy(policy) ||
> + rt_policy(policy) || dl_policy(policy);
> +}
>
> static inline int task_has_rt_policy(struct task_struct *p)
> {
> --
> 1.9.1
>

--
Henrik Austad

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