Commit 43e33f53 authored by Tejun Heo's avatar Tejun Heo Committed by Peter Zijlstra
Browse files

sched/core: Reorganize cgroup bandwidth control interface file reads 



- Update tg_get_cfs_*() to return u64 values. These are now used as the low
  level accessors to the fair's bandwidth configuration parameters.
  Translation to usecs takes place in these functions.

- Add tg_bandwidth() which reads all three bandwidth parameters using
  tg_get_cfs_*().

- Reimplement cgroup interface read functions using tg_bandwidth(). Drop cfs
  from the function names.

This is to prepare for adding bandwidth control support to sched_ext.
tg_bandwidth() will be used as the muxing point similar to tg_weight(). No
functional changes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250614012346.2358261-4-tj@kernel.org
parent de4c80c6

kernel/sched/core.c

+40 −18
Original line number Diff line number Diff line
@@ -9404,7 +9404,7 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota, 
	return 0;

}



static long tg_get_cfs_period(struct task_group *tg)

static u64 tg_get_cfs_period(struct task_group *tg)

{

	u64 cfs_period_us;
@@ -9414,12 +9414,12 @@ static long tg_get_cfs_period(struct task_group *tg) 
	return cfs_period_us;

}



static long tg_get_cfs_quota(struct task_group *tg)

static u64 tg_get_cfs_quota(struct task_group *tg)

{

	u64 quota_us;



	if (tg->cfs_bandwidth.quota == RUNTIME_INF)

		return -1;

		return RUNTIME_INF;



	quota_us = tg->cfs_bandwidth.quota;

	do_div(quota_us, NSEC_PER_USEC);
@@ -9427,7 +9427,7 @@ static long tg_get_cfs_quota(struct task_group *tg) 
	return quota_us;

}



static long tg_get_cfs_burst(struct task_group *tg)

static u64 tg_get_cfs_burst(struct task_group *tg)

{

	u64 burst_us;
@@ -9614,22 +9614,42 @@ static int cpu_cfs_local_stat_show(struct seq_file *sf, void *v) 
	return 0;

}



static u64 cpu_cfs_period_read_u64(struct cgroup_subsys_state *css,

static void tg_bandwidth(struct task_group *tg,

			 u64 *period_us_p, u64 *quota_us_p, u64 *burst_us_p)

{

	if (period_us_p)

		*period_us_p = tg_get_cfs_period(tg);

	if (quota_us_p)

		*quota_us_p = tg_get_cfs_quota(tg);

	if (burst_us_p)

		*burst_us_p = tg_get_cfs_burst(tg);

}



static u64 cpu_period_read_u64(struct cgroup_subsys_state *css,

			       struct cftype *cft)

{

	return tg_get_cfs_period(css_tg(css));

	u64 period_us;



	tg_bandwidth(css_tg(css), &period_us, NULL, NULL);

	return period_us;

}



static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,

static s64 cpu_quota_read_s64(struct cgroup_subsys_state *css,

			      struct cftype *cft)

{

	return tg_get_cfs_quota(css_tg(css));

	u64 quota_us;



	tg_bandwidth(css_tg(css), NULL, &quota_us, NULL);

	return quota_us;	/* (s64)RUNTIME_INF becomes -1 */

}



static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css,

static u64 cpu_burst_read_u64(struct cgroup_subsys_state *css,

			      struct cftype *cft)

{

	return tg_get_cfs_burst(css_tg(css));

	u64 burst_us;



	tg_bandwidth(css_tg(css), NULL, NULL, &burst_us);

	return burst_us;

}



static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
@@ -9712,17 +9732,17 @@ static struct cftype cpu_legacy_files[] = { 
#ifdef CONFIG_CFS_BANDWIDTH

	{

		.name = "cfs_period_us",

		.read_u64 = cpu_cfs_period_read_u64,

		.read_u64 = cpu_period_read_u64,

		.write_u64 = cpu_cfs_period_write_u64,

	},

	{

		.name = "cfs_quota_us",

		.read_s64 = cpu_cfs_quota_read_s64,

		.read_s64 = cpu_quota_read_s64,

		.write_s64 = cpu_cfs_quota_write_s64,

	},

	{

		.name = "cfs_burst_us",

		.read_u64 = cpu_cfs_burst_read_u64,

		.read_u64 = cpu_burst_read_u64,

		.write_u64 = cpu_cfs_burst_write_u64,

	},

	{
@@ -9944,8 +9964,10 @@ static int __maybe_unused cpu_period_quota_parse(char *buf, 
static int cpu_max_show(struct seq_file *sf, void *v)

{

	struct task_group *tg = css_tg(seq_css(sf));

	u64 period_us, quota_us;



	cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));

	tg_bandwidth(tg, &period_us, &quota_us, NULL);

	cpu_period_quota_print(sf, period_us, quota_us);

	return 0;

}
@@ -9996,7 +10018,7 @@ static struct cftype cpu_files[] = { 
	{

		.name = "max.burst",

		.flags = CFTYPE_NOT_ON_ROOT,

		.read_u64 = cpu_cfs_burst_read_u64,

		.read_u64 = cpu_burst_read_u64,

		.write_u64 = cpu_cfs_burst_write_u64,

	},

#endif /* CONFIG_CFS_BANDWIDTH */