From 50e7b416d2ab10b9771bd00a4d85df90ad2e4b37 Mon Sep 17 00:00:00 2001 From: Dietmar Eggemann Date: Thu, 28 Apr 2022 15:43:37 +0100 Subject: sched/fair: Remove sched_trace_*() helper functions We no longer need them as we can use DWARF debug info or BTF + pahole to re-generate the required structs to compile against them for a given kernel. This moves the burden of maintaining these helper functions to the module. https://github.com/qais-yousef/sched_tp Note that pahole v1.15 is required at least for using DWARF. And for BTF v1.23 which is not yet released will be required. There's alignment problem that will lead to crashes in earlier versions when used with BTF. We should have enough infrastructure to make these helper functions now obsolete, so remove them. [Rewrote commit message to reflect the new alternative] Signed-off-by: Dietmar Eggemann Signed-off-by: Qais Yousef Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220428144338.479094-2-qais.yousef@arm.com --- include/linux/sched.h | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 67f06f72c50e..fc74ea2578b7 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2378,20 +2378,6 @@ static inline void rseq_syscall(struct pt_regs *regs) #endif -const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq); -char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len); -int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq); - -const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq); -const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq); -const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq); - -int sched_trace_rq_cpu(struct rq *rq); -int sched_trace_rq_cpu_capacity(struct rq *rq); -int sched_trace_rq_nr_running(struct rq *rq); - -const struct cpumask *sched_trace_rd_span(struct root_domain *rd); - #ifdef CONFIG_SCHED_CORE extern void sched_core_free(struct task_struct *tsk); extern void sched_core_fork(struct task_struct *p); -- cgit v1.2.3 From d664e399128bd78b905ff480917e2c2d4949e101 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 13 Apr 2022 15:31:02 +0200 Subject: sched: Fix missing prototype warnings A W=1 build emits more than a dozen missing prototype warnings related to scheduler and scheduler specific includes. Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220413133024.249118058@linutronix.de --- include/linux/sched.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index fc74ea2578b7..a27316f5f737 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2388,4 +2388,6 @@ static inline void sched_core_free(struct task_struct *tsk) { } static inline void sched_core_fork(struct task_struct *p) { } #endif +extern void sched_set_stop_task(int cpu, struct task_struct *stop); + #endif -- cgit v1.2.3 From 1a90bfd220201fbe050dfc15deaac20ca5f15638 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 13 Apr 2022 15:31:05 +0200 Subject: smp: Make softirq handling RT safe in flush_smp_call_function_queue() flush_smp_call_function_queue() invokes do_softirq() which is not available on PREEMPT_RT. flush_smp_call_function_queue() is invoked from the idle task and the migration task with preemption or interrupts disabled. So RT kernels cannot process soft interrupts in that context as that has to acquire 'sleeping spinlocks' which is not possible with preemption or interrupts disabled and forbidden from the idle task anyway. The currently known SMP function call which raises a soft interrupt is in the block layer, but this functionality is not enabled on RT kernels due to latency and performance reasons. RT could wake up ksoftirqd unconditionally, but this wants to be avoided if there were soft interrupts pending already when this is invoked in the context of the migration task. The migration task might have preempted a threaded interrupt handler which raised a soft interrupt, but did not reach the local_bh_enable() to process it. The "running" ksoftirqd might prevent the handling in the interrupt thread context which is causing latency issues. Add a new function which handles this case explicitely for RT and falls back to do_softirq() on !RT kernels. In the RT case this warns when one of the flushed SMP function calls raised a soft interrupt so this can be investigated. [ tglx: Moved the RT part out of SMP code ] Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/YgKgL6aPj8aBES6G@linutronix.de Link: https://lore.kernel.org/r/20220413133024.356509586@linutronix.de --- include/linux/interrupt.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index f40754caaefa..a49fe8d88676 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -607,6 +607,15 @@ struct softirq_action asmlinkage void do_softirq(void); asmlinkage void __do_softirq(void); +#ifdef CONFIG_PREEMPT_RT +extern void do_softirq_post_smp_call_flush(unsigned int was_pending); +#else +static inline void do_softirq_post_smp_call_flush(unsigned int unused) +{ + do_softirq(); +} +#endif + extern void open_softirq(int nr, void (*action)(struct softirq_action *)); extern void softirq_init(void); extern void __raise_softirq_irqoff(unsigned int nr); -- cgit v1.2.3 From 546a3fee174969ff323d70ff27b1ef181f0d7ceb Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 17 May 2022 13:46:54 +0200 Subject: sched: Reverse sched_class layout Because GCC-12 is fully stupid about array bounds and it's just really hard to get a solid array definition from a linker script, flip the array order to avoid needing negative offsets :-/ This makes the whole relational pointer magic a little less obvious, but alas. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/YoOLLmLG7HRTXeEm@hirez.programming.kicks-ass.net --- include/asm-generic/vmlinux.lds.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 69138e9db787..7515a465ec03 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -126,13 +126,13 @@ */ #define SCHED_DATA \ STRUCT_ALIGN(); \ - __begin_sched_classes = .; \ - *(__idle_sched_class) \ - *(__fair_sched_class) \ - *(__rt_sched_class) \ - *(__dl_sched_class) \ + __sched_class_highest = .; \ *(__stop_sched_class) \ - __end_sched_classes = .; + *(__dl_sched_class) \ + *(__rt_sched_class) \ + *(__fair_sched_class) \ + *(__idle_sched_class) \ + __sched_class_lowest = .; /* The actual configuration determine if the init/exit sections * are handled as text/data or they can be discarded (which -- cgit v1.2.3 From 991d8d8142cad94f9c5c05db25e67fa83d6f772a Mon Sep 17 00:00:00 2001 From: Dietmar Eggemann Date: Fri, 13 May 2022 11:34:33 +0200 Subject: topology: Remove unused cpu_cluster_mask() default_topology[] uses cpu_clustergroup_mask() for the CLS level (guarded by CONFIG_SCHED_CLUSTER) which is currently provided by x86 (arch/x86/kernel/smpboot.c) and arm64 (drivers/base/arch_topology.c). Fixes: 778c558f49a2c ("sched: Add cluster scheduler level in core and related Kconfig for ARM64") Signed-off-by: Dietmar Eggemann Signed-off-by: Peter Zijlstra (Intel) Acked-by: Barry Song Link: https://lore.kernel.org/r/20220513093433.425163-1-dietmar.eggemann@arm.com --- include/linux/topology.h | 7 ------- 1 file changed, 7 deletions(-) (limited to 'include') diff --git a/include/linux/topology.h b/include/linux/topology.h index f19bc3626297..4564faafd0e1 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -240,13 +240,6 @@ static inline const struct cpumask *cpu_smt_mask(int cpu) } #endif -#if defined(CONFIG_SCHED_CLUSTER) && !defined(cpu_cluster_mask) -static inline const struct cpumask *cpu_cluster_mask(int cpu) -{ - return topology_cluster_cpumask(cpu); -} -#endif - static inline const struct cpumask *cpu_cpu_mask(int cpu) { return cpumask_of_node(cpu_to_node(cpu)); -- cgit v1.2.3