From 8a99b6833c884fa0e7919030d93fecedc69fc625 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 24 Mar 2021 11:43:21 +0100 Subject: [PATCH] sched: Move SCHED_DEBUG sysctl to debugfs Stop polluting sysctl with undocumented knobs that really are debug only, move them all to /debug/sched/ along with the existing /debug/sched_* files that already exist. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Greg Kroah-Hartman Tested-by: Valentin Schneider Link: https://lkml.kernel.org/r/20210412102001.287610138@infradead.org --- include/linux/sched/sysctl.h | 8 ++- kernel/sched/core.c | 4 +- kernel/sched/debug.c | 74 +++++++++++++++++++++++++-- kernel/sched/fair.c | 9 +--- kernel/sched/sched.h | 2 + kernel/sysctl.c | 96 ------------------------------------ 6 files changed, 80 insertions(+), 113 deletions(-) diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index 3c31ba88aca5..0a3f34638cf5 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -26,10 +26,11 @@ int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, enum { sysctl_hung_task_timeout_secs = 0 }; #endif +extern unsigned int sysctl_sched_child_runs_first; + extern unsigned int sysctl_sched_latency; extern unsigned int sysctl_sched_min_granularity; extern unsigned int sysctl_sched_wakeup_granularity; -extern unsigned int sysctl_sched_child_runs_first; enum sched_tunable_scaling { SCHED_TUNABLESCALING_NONE, @@ -37,7 +38,7 @@ enum sched_tunable_scaling { SCHED_TUNABLESCALING_LINEAR, SCHED_TUNABLESCALING_END, }; -extern enum sched_tunable_scaling sysctl_sched_tunable_scaling; +extern unsigned int sysctl_sched_tunable_scaling; extern unsigned int sysctl_numa_balancing_scan_delay; extern unsigned int sysctl_numa_balancing_scan_period_min; @@ -47,9 +48,6 @@ extern unsigned int sysctl_numa_balancing_scan_size; #ifdef CONFIG_SCHED_DEBUG extern __read_mostly unsigned int sysctl_sched_migration_cost; extern __read_mostly unsigned int sysctl_sched_nr_migrate; - -int sched_proc_update_handler(struct ctl_table *table, int write, - void *buffer, size_t *length, loff_t *ppos); #endif /* diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7d031da20df3..bac30db29d3f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5504,9 +5504,11 @@ static const struct file_operations sched_dynamic_fops = { .release = single_release, }; +extern struct dentry *debugfs_sched; + static __init int sched_init_debug_dynamic(void) { - debugfs_create_file("sched_preempt", 0644, NULL, NULL, &sched_dynamic_fops); + debugfs_create_file("sched_preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops); return 0; } late_initcall(sched_init_debug_dynamic); diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 4b49cc2af5c4..2093b9086e34 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -169,15 +169,81 @@ static const struct file_operations sched_feat_fops = { .release = single_release, }; +#ifdef CONFIG_SMP + +static ssize_t sched_scaling_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[16]; + + if (cnt > 15) + cnt = 15; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + if (kstrtouint(buf, 10, &sysctl_sched_tunable_scaling)) + return -EINVAL; + + if (sched_update_scaling()) + return -EINVAL; + + *ppos += cnt; + return cnt; +} + +static int sched_scaling_show(struct seq_file *m, void *v) +{ + seq_printf(m, "%d\n", sysctl_sched_tunable_scaling); + return 0; +} + +static int sched_scaling_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, sched_scaling_show, NULL); +} + +static const struct file_operations sched_scaling_fops = { + .open = sched_scaling_open, + .write = sched_scaling_write, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +#endif /* SMP */ + __read_mostly bool sched_debug_enabled; +struct dentry *debugfs_sched; + static __init int sched_init_debug(void) { - debugfs_create_file("sched_features", 0644, NULL, NULL, - &sched_feat_fops); + struct dentry __maybe_unused *numa; - debugfs_create_bool("sched_debug", 0644, NULL, - &sched_debug_enabled); + debugfs_sched = debugfs_create_dir("sched", NULL); + + debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops); + debugfs_create_bool("debug_enabled", 0644, debugfs_sched, &sched_debug_enabled); + + debugfs_create_u32("latency_ns", 0644, debugfs_sched, &sysctl_sched_latency); + debugfs_create_u32("min_granularity_ns", 0644, debugfs_sched, &sysctl_sched_min_granularity); + debugfs_create_u32("wakeup_granularity_ns", 0644, debugfs_sched, &sysctl_sched_wakeup_granularity); + +#ifdef CONFIG_SMP + debugfs_create_file("tunable_scaling", 0644, debugfs_sched, NULL, &sched_scaling_fops); + debugfs_create_u32("migration_cost_ns", 0644, debugfs_sched, &sysctl_sched_migration_cost); + debugfs_create_u32("nr_migrate", 0644, debugfs_sched, &sysctl_sched_nr_migrate); +#endif + +#ifdef CONFIG_NUMA_BALANCING + numa = debugfs_create_dir("numa_balancing", debugfs_sched); + + debugfs_create_u32("scan_delay_ms", 0644, numa, &sysctl_numa_balancing_scan_delay); + debugfs_create_u32("scan_period_min_ms", 0644, numa, &sysctl_numa_balancing_scan_period_min); + debugfs_create_u32("scan_period_max_ms", 0644, numa, &sysctl_numa_balancing_scan_period_max); + debugfs_create_u32("scan_size_mb", 0644, numa, &sysctl_numa_balancing_scan_size); +#endif return 0; } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9b8ae02f1994..b3ea14c08a9b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -49,7 +49,7 @@ static unsigned int normalized_sysctl_sched_latency = 6000000ULL; * * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) */ -enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG; +unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG; /* * Minimal preemption granularity for CPU-bound tasks: @@ -634,15 +634,10 @@ struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) * Scheduling class statistics methods: */ -int sched_proc_update_handler(struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos) +int sched_update_scaling(void) { - int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); unsigned int factor = get_update_sysctl_factor(); - if (ret || !write) - return ret; - sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency, sysctl_sched_min_granularity); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 7e7e936b4938..123ff3bb90bc 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1568,6 +1568,8 @@ static inline void unregister_sched_domain_sysctl(void) } #endif +extern int sched_update_scaling(void); + extern void flush_smp_call_function_from_idle(void); #else /* !CONFIG_SMP: */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 17f1cc9988ca..4bff44d47154 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -184,17 +184,6 @@ static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT; int sysctl_legacy_va_layout; #endif -#ifdef CONFIG_SCHED_DEBUG -static int min_sched_granularity_ns = 100000; /* 100 usecs */ -static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */ -static int min_wakeup_granularity_ns; /* 0 usecs */ -static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */ -#ifdef CONFIG_SMP -static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE; -static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1; -#endif /* CONFIG_SMP */ -#endif /* CONFIG_SCHED_DEBUG */ - #ifdef CONFIG_COMPACTION static int min_extfrag_threshold; static int max_extfrag_threshold = 1000; @@ -1659,91 +1648,6 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, -#ifdef CONFIG_SCHED_DEBUG - { - .procname = "sched_min_granularity_ns", - .data = &sysctl_sched_min_granularity, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = sched_proc_update_handler, - .extra1 = &min_sched_granularity_ns, - .extra2 = &max_sched_granularity_ns, - }, - { - .procname = "sched_latency_ns", - .data = &sysctl_sched_latency, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = sched_proc_update_handler, - .extra1 = &min_sched_granularity_ns, - .extra2 = &max_sched_granularity_ns, - }, - { - .procname = "sched_wakeup_granularity_ns", - .data = &sysctl_sched_wakeup_granularity, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = sched_proc_update_handler, - .extra1 = &min_wakeup_granularity_ns, - .extra2 = &max_wakeup_granularity_ns, - }, -#ifdef CONFIG_SMP - { - .procname = "sched_tunable_scaling", - .data = &sysctl_sched_tunable_scaling, - .maxlen = sizeof(enum sched_tunable_scaling), - .mode = 0644, - .proc_handler = sched_proc_update_handler, - .extra1 = &min_sched_tunable_scaling, - .extra2 = &max_sched_tunable_scaling, - }, - { - .procname = "sched_migration_cost_ns", - .data = &sysctl_sched_migration_cost, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { - .procname = "sched_nr_migrate", - .data = &sysctl_sched_nr_migrate, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, -#endif /* CONFIG_SMP */ -#ifdef CONFIG_NUMA_BALANCING - { - .procname = "numa_balancing_scan_delay_ms", - .data = &sysctl_numa_balancing_scan_delay, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { - .procname = "numa_balancing_scan_period_min_ms", - .data = &sysctl_numa_balancing_scan_period_min, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { - .procname = "numa_balancing_scan_period_max_ms", - .data = &sysctl_numa_balancing_scan_period_max, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { - .procname = "numa_balancing_scan_size_mb", - .data = &sysctl_numa_balancing_scan_size, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = SYSCTL_ONE, - }, -#endif /* CONFIG_NUMA_BALANCING */ -#endif /* CONFIG_SCHED_DEBUG */ #ifdef CONFIG_SCHEDSTATS { .procname = "sched_schedstats",