diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 15 | ||||
| -rw-r--r-- | kernel/sched_debug.c | 10 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 13 | ||||
| -rw-r--r-- | kernel/sysctl.c | 14 |
4 files changed, 51 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index b54ecf84b6be..116efed962c6 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7033,7 +7033,20 @@ cpumask_var_t nohz_cpu_mask; static void update_sysctl(void) { unsigned int cpus = min(num_online_cpus(), 8U); - unsigned int factor = 1 + ilog2(cpus); + unsigned int factor; + + switch (sysctl_sched_tunable_scaling) { + case SCHED_TUNABLESCALING_NONE: + factor = 1; + break; + case SCHED_TUNABLESCALING_LINEAR: + factor = cpus; + break; + case SCHED_TUNABLESCALING_LOG: + default: + factor = 1 + ilog2(cpus); + break; + } #define SET_SYSCTL(name) \ (sysctl_##name = (factor) * normalized_sysctl_##name) diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 5fda66615fee..0fc5287fe80f 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -309,6 +309,12 @@ static void print_cpu(struct seq_file *m, int cpu) print_rq(m, rq, cpu); } +static const char *sched_tunable_scaling_names[] = { + "none", + "logaritmic", + "linear" +}; + static int sched_debug_show(struct seq_file *m, void *v) { u64 now = ktime_to_ns(ktime_get()); @@ -334,6 +340,10 @@ static int sched_debug_show(struct seq_file *m, void *v) #undef PN #undef P + SEQ_printf(m, " .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling", + sysctl_sched_tunable_scaling, + sched_tunable_scaling_names[sysctl_sched_tunable_scaling]); + for_each_online_cpu(cpu) print_cpu(m, cpu); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 71b3458245e5..455106d318a8 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -21,6 +21,7 @@ */ #include <linux/latencytop.h> +#include <linux/sched.h> /* * Targeted preemption latency for CPU-bound tasks: @@ -38,6 +39,18 @@ unsigned int sysctl_sched_latency = 5000000ULL; unsigned int normalized_sysctl_sched_latency = 5000000ULL; /* + * The initial- and re-scaling of tunables is configurable + * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) + * + * Options are: + * SCHED_TUNABLESCALING_NONE - unscaled, always *1 + * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus) + * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus + */ +enum sched_tunable_scaling sysctl_sched_tunable_scaling + = SCHED_TUNABLESCALING_LOG; + +/* * Minimal preemption granularity for CPU-bound tasks: * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e5cc53514caa..d10406e5fdfe 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -251,6 +251,8 @@ 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 */ +static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE; +static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1; #endif static struct ctl_table kern_table[] = { @@ -306,6 +308,18 @@ static struct ctl_table kern_table[] = { }, { .ctl_name = CTL_UNNUMBERED, + .procname = "sched_tunable_scaling", + .data = &sysctl_sched_tunable_scaling, + .maxlen = sizeof(enum sched_tunable_scaling), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &min_sched_tunable_scaling, + .extra2 = &max_sched_tunable_scaling, + }, + + { + .ctl_name = CTL_UNNUMBERED, .procname = "sched_shares_thresh", .data = &sysctl_sched_shares_thresh, .maxlen = sizeof(unsigned int), |