From: Joel Fernandes joelagnelf@nvidia.com
When a sched_ext server is loaded, tasks in the fair class are automatically moved to the sched_ext class. Add support to modify the ext server parameters similar to how the fair server parameters are modified.
Re-use common code between ext and fair servers as needed.
v2: - use dl_se->dl_server to determine if dl_se is a DL server (Peter Zijlstra) - depend on CONFIG_SCHED_CLASS_EXT (Andrea Righi)
Tested-by: Christian Loehle christian.loehle@arm.com Reviewed-by: Juri Lelli juri.lelli@redhat.com Co-developed-by: Andrea Righi arighi@nvidia.com Signed-off-by: Andrea Righi arighi@nvidia.com Signed-off-by: Joel Fernandes joelagnelf@nvidia.com --- kernel/sched/debug.c | 157 ++++++++++++++++++++++++++++++++++++------- 1 file changed, 133 insertions(+), 24 deletions(-)
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index dd793f8f3858a..2e9896668c6fd 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -336,14 +336,16 @@ enum dl_param { DL_PERIOD, };
-static unsigned long fair_server_period_max = (1UL << 22) * NSEC_PER_USEC; /* ~4 seconds */ -static unsigned long fair_server_period_min = (100) * NSEC_PER_USEC; /* 100 us */ +static unsigned long dl_server_period_max = (1UL << 22) * NSEC_PER_USEC; /* ~4 seconds */ +static unsigned long dl_server_period_min = (100) * NSEC_PER_USEC; /* 100 us */
-static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos, enum dl_param param) +static ssize_t sched_server_write_common(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos, enum dl_param param, + void *server) { long cpu = (long) ((struct seq_file *) filp->private_data)->private; struct rq *rq = cpu_rq(cpu); + struct sched_dl_entity *dl_se = (struct sched_dl_entity *)server; u64 runtime, period; int retval = 0; size_t err; @@ -356,8 +358,8 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu scoped_guard (rq_lock_irqsave, rq) { bool is_active;
- runtime = rq->fair_server.dl_runtime; - period = rq->fair_server.dl_period; + runtime = dl_se->dl_runtime; + period = dl_se->dl_period;
switch (param) { case DL_RUNTIME: @@ -373,25 +375,25 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu }
if (runtime > period || - period > fair_server_period_max || - period < fair_server_period_min) { + period > dl_server_period_max || + period < dl_server_period_min) { return -EINVAL; }
- is_active = dl_server_active(&rq->fair_server); + is_active = dl_server_active(dl_se); if (is_active) { update_rq_clock(rq); - dl_server_stop(&rq->fair_server); + dl_server_stop(dl_se); }
- retval = dl_server_apply_params(&rq->fair_server, runtime, period, 0); + retval = dl_server_apply_params(dl_se, runtime, period, 0);
if (!runtime) - printk_deferred("Fair server disabled in CPU %d, system may crash due to starvation.\n", - cpu_of(rq)); + printk_deferred("%s server disabled in CPU %d, system may crash due to starvation.\n", + server == &rq->fair_server ? "Fair" : "Ext", cpu_of(rq));
if (is_active && runtime) - dl_server_start(&rq->fair_server); + dl_server_start(dl_se);
if (retval < 0) return retval; @@ -401,36 +403,42 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu return cnt; }
-static size_t sched_fair_server_show(struct seq_file *m, void *v, enum dl_param param) +static size_t sched_server_show_common(struct seq_file *m, void *v, enum dl_param param, + void *server) { - unsigned long cpu = (unsigned long) m->private; - struct rq *rq = cpu_rq(cpu); + struct sched_dl_entity *dl_se = (struct sched_dl_entity *)server; u64 value;
switch (param) { case DL_RUNTIME: - value = rq->fair_server.dl_runtime; + value = dl_se->dl_runtime; break; case DL_PERIOD: - value = rq->fair_server.dl_period; + value = dl_se->dl_period; break; }
seq_printf(m, "%llu\n", value); return 0; - }
static ssize_t sched_fair_server_runtime_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_RUNTIME); + long cpu = (long) ((struct seq_file *) filp->private_data)->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_write_common(filp, ubuf, cnt, ppos, DL_RUNTIME, + &rq->fair_server); }
static int sched_fair_server_runtime_show(struct seq_file *m, void *v) { - return sched_fair_server_show(m, v, DL_RUNTIME); + unsigned long cpu = (unsigned long) m->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_show_common(m, v, DL_RUNTIME, &rq->fair_server); }
static int sched_fair_server_runtime_open(struct inode *inode, struct file *filp) @@ -446,16 +454,57 @@ static const struct file_operations fair_server_runtime_fops = { .release = single_release, };
+#ifdef CONFIG_SCHED_CLASS_EXT +static ssize_t +sched_ext_server_runtime_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + long cpu = (long) ((struct seq_file *) filp->private_data)->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_write_common(filp, ubuf, cnt, ppos, DL_RUNTIME, + &rq->ext_server); +} + +static int sched_ext_server_runtime_show(struct seq_file *m, void *v) +{ + unsigned long cpu = (unsigned long) m->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_show_common(m, v, DL_RUNTIME, &rq->ext_server); +} + +static int sched_ext_server_runtime_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, sched_ext_server_runtime_show, inode->i_private); +} + +static const struct file_operations ext_server_runtime_fops = { + .open = sched_ext_server_runtime_open, + .write = sched_ext_server_runtime_write, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif /* CONFIG_SCHED_CLASS_EXT */ + static ssize_t sched_fair_server_period_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_PERIOD); + long cpu = (long) ((struct seq_file *) filp->private_data)->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_write_common(filp, ubuf, cnt, ppos, DL_PERIOD, + &rq->fair_server); }
static int sched_fair_server_period_show(struct seq_file *m, void *v) { - return sched_fair_server_show(m, v, DL_PERIOD); + unsigned long cpu = (unsigned long) m->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_show_common(m, v, DL_PERIOD, &rq->fair_server); }
static int sched_fair_server_period_open(struct inode *inode, struct file *filp) @@ -471,6 +520,40 @@ static const struct file_operations fair_server_period_fops = { .release = single_release, };
+#ifdef CONFIG_SCHED_CLASS_EXT +static ssize_t +sched_ext_server_period_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + long cpu = (long) ((struct seq_file *) filp->private_data)->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_write_common(filp, ubuf, cnt, ppos, DL_PERIOD, + &rq->ext_server); +} + +static int sched_ext_server_period_show(struct seq_file *m, void *v) +{ + unsigned long cpu = (unsigned long) m->private; + struct rq *rq = cpu_rq(cpu); + + return sched_server_show_common(m, v, DL_PERIOD, &rq->ext_server); +} + +static int sched_ext_server_period_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, sched_ext_server_period_show, inode->i_private); +} + +static const struct file_operations ext_server_period_fops = { + .open = sched_ext_server_period_open, + .write = sched_ext_server_period_write, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif /* CONFIG_SCHED_CLASS_EXT */ + static struct dentry *debugfs_sched;
static void debugfs_fair_server_init(void) @@ -494,6 +577,29 @@ static void debugfs_fair_server_init(void) } }
+#ifdef CONFIG_SCHED_CLASS_EXT +static void debugfs_ext_server_init(void) +{ + struct dentry *d_ext; + unsigned long cpu; + + d_ext = debugfs_create_dir("ext_server", debugfs_sched); + if (!d_ext) + return; + + for_each_possible_cpu(cpu) { + struct dentry *d_cpu; + char buf[32]; + + snprintf(buf, sizeof(buf), "cpu%lu", cpu); + d_cpu = debugfs_create_dir(buf, d_ext); + + debugfs_create_file("runtime", 0644, d_cpu, (void *) cpu, &ext_server_runtime_fops); + debugfs_create_file("period", 0644, d_cpu, (void *) cpu, &ext_server_period_fops); + } +} +#endif /* CONFIG_SCHED_CLASS_EXT */ + static __init int sched_init_debug(void) { struct dentry __maybe_unused *numa; @@ -532,6 +638,9 @@ static __init int sched_init_debug(void) debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops);
debugfs_fair_server_init(); +#ifdef CONFIG_SCHED_CLASS_EXT + debugfs_ext_server_init(); +#endif
return 0; }