[PATCH 4/9] sched: Move SCHED_DEBUG to debugfs
From: Peter Zijlstra
Date: Fri Mar 26 2021 - 06:43:43 EST
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) <peterz@xxxxxxxxxxxxx>
---
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(-)
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -26,10 +26,11 @@ int proc_dohung_task_timeout_secs(struct
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_balancin
#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
/*
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5504,9 +5504,11 @@ static const struct file_operations sche
.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);
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -169,15 +169,81 @@ static const struct file_operations sche
.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_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_bool("sched_debug", 0644, NULL,
- &sched_debug_enabled);
+ 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;
}
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -49,7 +49,7 @@ static unsigned int normalized_sysctl_sc
*
* (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:
@@ -627,15 +627,10 @@ struct sched_entity *__pick_last_entity(
* 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);
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1569,6 +1569,8 @@ static inline void unregister_sched_doma
}
#endif
+extern int sched_update_scaling(void);
+
extern void flush_smp_call_function_from_idle(void);
#else /* !CONFIG_SMP: */
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -184,17 +184,6 @@ static enum sysctl_writes_mode sysctl_wr
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",