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: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250614012346.2358261-4-tj@kernel.org
This commit is contained in:
Tejun Heo 2025-06-13 15:23:29 -10:00 committed by Peter Zijlstra
parent de4c80c696
commit 43e33f53e2

View File

@ -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,
struct cftype *cft)
static void tg_bandwidth(struct task_group *tg,
u64 *period_us_p, u64 *quota_us_p, u64 *burst_us_p)
{
return tg_get_cfs_period(css_tg(css));
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 s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,
struct cftype *cft)
static u64 cpu_period_read_u64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
return tg_get_cfs_quota(css_tg(css));
u64 period_us;
tg_bandwidth(css_tg(css), &period_us, NULL, NULL);
return period_us;
}
static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css,
struct cftype *cft)
static s64 cpu_quota_read_s64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
return tg_get_cfs_burst(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_burst_read_u64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
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 */