From: Juri Lelli <juri.le...@gmail.com> This patch adds the possibility to get the delivery of two signals whenever there is a runtime overrun or a deadline miss, respectively. The request is done through the sched_flags field within the sched_attr structure.
Forward port of https://lkml.org/lkml/2009/10/16/170 Signed-off-by: Juri Lelli <juri.le...@gmail.com> Signed-off-by: Claudio Scordino <clau...@evidence.eu.com> Signed-off-by: Luca Abeni <luca.ab...@santannapisa.it> Cc: Tommaso Cucinotta <tommaso.cucino...@sssup.it> CC: Peter Zijlstra <pet...@infradead.org> CC: Ingo Molnar <mi...@redhat.com> CC: Thomas Gleixner <t...@linutronix.de> Cc: Mathieu Poirier <mathieu.poir...@linaro.org> --- include/linux/sched.h | 8 ++++++++ include/uapi/linux/sched.h | 2 ++ kernel/sched/core.c | 3 ++- kernel/sched/deadline.c | 13 +++++++++++++ kernel/time/posix-cpu-timers.c | 26 ++++++++++++++++++++++++++ 5 files changed, 51 insertions(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 0f897df..285d1b4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -473,11 +473,19 @@ struct sched_dl_entity { * has not been executed yet. This flag is useful to avoid race * conditions between the inactive timer handler and the wakeup * code. + * + * @dl_overrun tells if the task asked to be informed about budget + * overruns. + * + * @dl_dmiss tells if the task asked to be informed about deadline + * misses. */ int dl_throttled : 1; int dl_boosted : 1; int dl_yielded : 1; int dl_non_contending : 1; + int dl_overrun : 1; + int dl_dmiss : 1; /* * Bandwidth enforcement timer. Each -deadline task has its diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h index e2a6c7b..544be0c 100644 --- a/include/uapi/linux/sched.h +++ b/include/uapi/linux/sched.h @@ -48,5 +48,7 @@ */ #define SCHED_FLAG_RESET_ON_FORK 0x01 #define SCHED_FLAG_RECLAIM 0x02 +#define SCHED_FLAG_DL_OVERRUN 0x04 +#define SCHED_FLAG_DL_DMISS 0x08 #endif /* _UAPI_LINUX_SCHED_H */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 97227df..d79df7a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4041,7 +4041,8 @@ static int __sched_setscheduler(struct task_struct *p, } if (attr->sched_flags & - ~(SCHED_FLAG_RESET_ON_FORK | SCHED_FLAG_RECLAIM)) + ~(SCHED_FLAG_RESET_ON_FORK | SCHED_FLAG_RECLAIM | + SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_DL_DMISS)) return -EINVAL; /* diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 8d1b946..8c1aa61 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1154,6 +1154,17 @@ static void update_curr_dl(struct rq *rq) throttle: if (dl_runtime_exceeded(dl_se) || dl_se->dl_yielded) { dl_se->dl_throttled = 1; + + /* + * If requested, inform the user about deadline misses and/or + * runtime overruns. + */ + if (unlikely(dl_se->flags & SCHED_FLAG_DL_DMISS && + dl_time_before(dl_se->deadline, rq_clock(rq)))) + dl_se->dl_dmiss = 1; + if (dl_se->flags & SCHED_FLAG_DL_OVERRUN) + dl_se->dl_overrun = 1; + __dequeue_task_dl(rq, curr, 0); if (unlikely(dl_se->dl_boosted || !start_dl_timer(curr))) enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH); @@ -2565,6 +2576,8 @@ void __dl_clear_params(struct task_struct *p) dl_se->dl_throttled = 0; dl_se->dl_yielded = 0; dl_se->dl_non_contending = 0; + dl_se->dl_overrun = 0; + dl_se->dl_dmiss = 0; } bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr) diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 8585ad6..f3616c5 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -13,6 +13,7 @@ #include <linux/tick.h> #include <linux/workqueue.h> #include <linux/compat.h> +#include <linux/sched/deadline.h> #include "posix-timers.h" @@ -790,6 +791,22 @@ check_timers_list(struct list_head *timers, return 0; } +static inline void check_dl_overrun(struct task_struct *tsk) +{ + if (tsk->dl.dl_overrun) { + tsk->dl.dl_overrun = 0; + pr_info("runtime overrun: %s[%d]\n", + tsk->comm, task_pid_nr(tsk)); + __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); + } + if (tsk->dl.dl_dmiss) { + tsk->dl.dl_dmiss = 0; + pr_info("scheduling deadline miss: %s[%d]\n", + tsk->comm, task_pid_nr(tsk)); + __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); + } +} + /* * Check for any per-thread CPU timers that have fired and move them off * the tsk->cpu_timers[N] list onto the firing list. Here we update the @@ -803,6 +820,9 @@ static void check_thread_timers(struct task_struct *tsk, u64 expires; unsigned long soft; + if (dl_task(tsk)) + check_dl_overrun(tsk); + /* * If cputime_expires is zero, then there are no active * per thread CPU timers. @@ -905,6 +925,9 @@ static void check_process_timers(struct task_struct *tsk, struct task_cputime cputime; unsigned long soft; + if (dl_task(tsk)) + check_dl_overrun(tsk); + /* * If cputimer is not running, then there are no active * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU). @@ -1110,6 +1133,9 @@ static inline int fastpath_timer_check(struct task_struct *tsk) return 1; } + if (dl_task(tsk) && (tsk->dl.dl_overrun || tsk->dl.dl_dmiss)) + return 1; + return 0; } -- 2.7.4
