* [PATCH 1/4] sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h
2025-06-14 1:23 [PATCHSET tip/sched/core] sched/core: Reorganize bandwidth control interface handling Tejun Heo
@ 2025-06-14 1:23 ` Tejun Heo
2025-06-20 9:49 ` [tip: sched/core] " tip-bot2 for Tejun Heo
2025-06-14 1:23 ` [PATCH 2/4] sched/core: Relocate tg_get_cfs_*() and cpu_cfs_*_read_*() Tejun Heo
` (2 subsequent siblings)
3 siblings, 1 reply; 9+ messages in thread
From: Tejun Heo @ 2025-06-14 1:23 UTC (permalink / raw)
To: mingo, peterz; +Cc: linux-kernel, sched-ext, void, arighi, changwoo, Tejun Heo
max_cfs_quota_period is defined in core.c but has a declaration in fair.c.
Move the declaration to kernel/sched/sched.h. Also, move
default_cfs_period() from fair.c to sched.h. No functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
kernel/sched/fair.c | 11 -----------
kernel/sched/sched.h | 13 +++++++++++++
2 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 6b17d3da034a..707be4570430 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5617,15 +5617,6 @@ void cfs_bandwidth_usage_inc(void) {}
void cfs_bandwidth_usage_dec(void) {}
#endif /* !CONFIG_JUMP_LABEL */
-/*
- * default period for cfs group bandwidth.
- * default: 0.1s, units: nanoseconds
- */
-static inline u64 default_cfs_period(void)
-{
- return 100000000ULL;
-}
-
static inline u64 sched_cfs_bandwidth_slice(void)
{
return (u64)sysctl_sched_cfs_bandwidth_slice * NSEC_PER_USEC;
@@ -6405,8 +6396,6 @@ static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
return HRTIMER_NORESTART;
}
-extern const u64 max_cfs_quota_period;
-
static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
{
struct cfs_bandwidth *cfs_b =
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c323d015486c..e00b80cd998e 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -402,6 +402,19 @@ static inline bool dl_server_active(struct sched_dl_entity *dl_se)
extern struct list_head task_groups;
+#ifdef CONFIG_CFS_BANDWIDTH
+extern const u64 max_cfs_quota_period;
+
+/*
+ * default period for cfs group bandwidth.
+ * default: 0.1s, units: nanoseconds
+ */
+static inline u64 default_cfs_period(void)
+{
+ return 100000000ULL;
+}
+#endif /* CONFIG_CFS_BANDWIDTH */
+
struct cfs_bandwidth {
#ifdef CONFIG_CFS_BANDWIDTH
raw_spinlock_t lock;
--
2.49.0
^ permalink raw reply [flat|nested] 9+ messages in thread* [tip: sched/core] sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h
2025-06-14 1:23 ` [PATCH 1/4] sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h Tejun Heo
@ 2025-06-20 9:49 ` tip-bot2 for Tejun Heo
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot2 for Tejun Heo @ 2025-06-20 9:49 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Tejun Heo, Peter Zijlstra (Intel), x86, linux-kernel
The following commit has been merged into the sched/core branch of tip:
Commit-ID: d403a3689af5c3a3e3ac6e282958d0eaa69ca47f
Gitweb: https://git.kernel.org/tip/d403a3689af5c3a3e3ac6e282958d0eaa69ca47f
Author: Tejun Heo <tj@kernel.org>
AuthorDate: Fri, 13 Jun 2025 15:23:27 -10:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 18 Jun 2025 13:59:56 +02:00
sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h
max_cfs_quota_period is defined in core.c but has a declaration in fair.c.
Move the declaration to kernel/sched/sched.h. Also, move
default_cfs_period() from fair.c to sched.h. 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/20250614012346.2358261-2-tj@kernel.org
---
kernel/sched/fair.c | 11 -----------
kernel/sched/sched.h | 13 +++++++++++++
2 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 6b17d3d..707be45 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5617,15 +5617,6 @@ void cfs_bandwidth_usage_inc(void) {}
void cfs_bandwidth_usage_dec(void) {}
#endif /* !CONFIG_JUMP_LABEL */
-/*
- * default period for cfs group bandwidth.
- * default: 0.1s, units: nanoseconds
- */
-static inline u64 default_cfs_period(void)
-{
- return 100000000ULL;
-}
-
static inline u64 sched_cfs_bandwidth_slice(void)
{
return (u64)sysctl_sched_cfs_bandwidth_slice * NSEC_PER_USEC;
@@ -6405,8 +6396,6 @@ static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
return HRTIMER_NORESTART;
}
-extern const u64 max_cfs_quota_period;
-
static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
{
struct cfs_bandwidth *cfs_b =
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c323d01..e00b80c 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -402,6 +402,19 @@ static inline bool dl_server_active(struct sched_dl_entity *dl_se)
extern struct list_head task_groups;
+#ifdef CONFIG_CFS_BANDWIDTH
+extern const u64 max_cfs_quota_period;
+
+/*
+ * default period for cfs group bandwidth.
+ * default: 0.1s, units: nanoseconds
+ */
+static inline u64 default_cfs_period(void)
+{
+ return 100000000ULL;
+}
+#endif /* CONFIG_CFS_BANDWIDTH */
+
struct cfs_bandwidth {
#ifdef CONFIG_CFS_BANDWIDTH
raw_spinlock_t lock;
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH 2/4] sched/core: Relocate tg_get_cfs_*() and cpu_cfs_*_read_*()
2025-06-14 1:23 [PATCHSET tip/sched/core] sched/core: Reorganize bandwidth control interface handling Tejun Heo
2025-06-14 1:23 ` [PATCH 1/4] sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h Tejun Heo
@ 2025-06-14 1:23 ` Tejun Heo
2025-06-20 9:49 ` [tip: sched/core] " tip-bot2 for Tejun Heo
2025-06-14 1:23 ` [PATCH 3/4] sched/core: Reorganize cgroup bandwidth control interface file reads Tejun Heo
2025-06-14 1:23 ` [PATCH 4/4] sched/core: Reorganize cgroup bandwidth control interface file writes Tejun Heo
3 siblings, 1 reply; 9+ messages in thread
From: Tejun Heo @ 2025-06-14 1:23 UTC (permalink / raw)
To: mingo, peterz; +Cc: linux-kernel, sched-ext, void, arighi, changwoo, Tejun Heo
Collect the getters, relocate the trivial interface file wrappers, and put
all of them in period, quota, burst order to prepare for future changes.
Pure reordering. No functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
kernel/sched/core.c | 134 ++++++++++++++++++++++----------------------
1 file changed, 67 insertions(+), 67 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a03c3c1d7f50..dc9668a6592f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9404,20 +9404,14 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota,
return 0;
}
-static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
+static long tg_get_cfs_period(struct task_group *tg)
{
- u64 quota, period, burst;
+ u64 cfs_period_us;
- period = ktime_to_ns(tg->cfs_bandwidth.period);
- burst = tg->cfs_bandwidth.burst;
- if (cfs_quota_us < 0)
- quota = RUNTIME_INF;
- else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC)
- quota = (u64)cfs_quota_us * NSEC_PER_USEC;
- else
- return -EINVAL;
+ cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period);
+ do_div(cfs_period_us, NSEC_PER_USEC);
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
+ return cfs_period_us;
}
static long tg_get_cfs_quota(struct task_group *tg)
@@ -9433,6 +9427,16 @@ static long tg_get_cfs_quota(struct task_group *tg)
return quota_us;
}
+static long tg_get_cfs_burst(struct task_group *tg)
+{
+ u64 burst_us;
+
+ burst_us = tg->cfs_bandwidth.burst;
+ do_div(burst_us, NSEC_PER_USEC);
+
+ return burst_us;
+}
+
static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
{
u64 quota, period, burst;
@@ -9447,14 +9451,20 @@ static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
-static long tg_get_cfs_period(struct task_group *tg)
+static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
{
- u64 cfs_period_us;
+ u64 quota, period, burst;
- cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period);
- do_div(cfs_period_us, NSEC_PER_USEC);
+ period = ktime_to_ns(tg->cfs_bandwidth.period);
+ burst = tg->cfs_bandwidth.burst;
+ if (cfs_quota_us < 0)
+ quota = RUNTIME_INF;
+ else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC)
+ quota = (u64)cfs_quota_us * NSEC_PER_USEC;
+ else
+ return -EINVAL;
- return cfs_period_us;
+ return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us)
@@ -9471,52 +9481,6 @@ static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us)
return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
-static long tg_get_cfs_burst(struct task_group *tg)
-{
- u64 burst_us;
-
- burst_us = tg->cfs_bandwidth.burst;
- do_div(burst_us, NSEC_PER_USEC);
-
- return burst_us;
-}
-
-static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return tg_get_cfs_quota(css_tg(css));
-}
-
-static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css,
- struct cftype *cftype, s64 cfs_quota_us)
-{
- return tg_set_cfs_quota(css_tg(css), cfs_quota_us);
-}
-
-static u64 cpu_cfs_period_read_u64(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return tg_get_cfs_period(css_tg(css));
-}
-
-static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_period_us)
-{
- return tg_set_cfs_period(css_tg(css), cfs_period_us);
-}
-
-static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return tg_get_cfs_burst(css_tg(css));
-}
-
-static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_burst_us)
-{
- return tg_set_cfs_burst(css_tg(css), cfs_burst_us);
-}
-
struct cfs_schedulable_data {
struct task_group *tg;
u64 period, quota;
@@ -9649,6 +9613,42 @@ 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)
+{
+ return tg_get_cfs_period(css_tg(css));
+}
+
+static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return tg_get_cfs_quota(css_tg(css));
+}
+
+static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return tg_get_cfs_burst(css_tg(css));
+}
+
+static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 cfs_period_us)
+{
+ return tg_set_cfs_period(css_tg(css), cfs_period_us);
+}
+
+static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, s64 cfs_quota_us)
+{
+ return tg_set_cfs_quota(css_tg(css), cfs_quota_us);
+}
+
+static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 cfs_burst_us)
+{
+ return tg_set_cfs_burst(css_tg(css), cfs_burst_us);
+}
#endif /* CONFIG_CFS_BANDWIDTH */
#ifdef CONFIG_RT_GROUP_SCHED
@@ -9710,16 +9710,16 @@ static struct cftype cpu_legacy_files[] = {
},
#endif
#ifdef CONFIG_CFS_BANDWIDTH
- {
- .name = "cfs_quota_us",
- .read_s64 = cpu_cfs_quota_read_s64,
- .write_s64 = cpu_cfs_quota_write_s64,
- },
{
.name = "cfs_period_us",
.read_u64 = cpu_cfs_period_read_u64,
.write_u64 = cpu_cfs_period_write_u64,
},
+ {
+ .name = "cfs_quota_us",
+ .read_s64 = cpu_cfs_quota_read_s64,
+ .write_s64 = cpu_cfs_quota_write_s64,
+ },
{
.name = "cfs_burst_us",
.read_u64 = cpu_cfs_burst_read_u64,
--
2.49.0
^ permalink raw reply [flat|nested] 9+ messages in thread* [tip: sched/core] sched/core: Relocate tg_get_cfs_*() and cpu_cfs_*_read_*()
2025-06-14 1:23 ` [PATCH 2/4] sched/core: Relocate tg_get_cfs_*() and cpu_cfs_*_read_*() Tejun Heo
@ 2025-06-20 9:49 ` tip-bot2 for Tejun Heo
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot2 for Tejun Heo @ 2025-06-20 9:49 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Tejun Heo, Peter Zijlstra (Intel), x86, linux-kernel
The following commit has been merged into the sched/core branch of tip:
Commit-ID: de4c80c6963e130707ead16a544a387f811dbd87
Gitweb: https://git.kernel.org/tip/de4c80c6963e130707ead16a544a387f811dbd87
Author: Tejun Heo <tj@kernel.org>
AuthorDate: Fri, 13 Jun 2025 15:23:28 -10:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 18 Jun 2025 13:59:57 +02:00
sched/core: Relocate tg_get_cfs_*() and cpu_cfs_*_read_*()
Collect the getters, relocate the trivial interface file wrappers, and put
all of them in period, quota, burst order to prepare for future changes.
Pure reordering. 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/20250614012346.2358261-3-tj@kernel.org
---
kernel/sched/core.c | 134 +++++++++++++++++++++----------------------
1 file changed, 67 insertions(+), 67 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a03c3c1..dc9668a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9404,20 +9404,14 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota,
return 0;
}
-static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
+static long tg_get_cfs_period(struct task_group *tg)
{
- u64 quota, period, burst;
+ u64 cfs_period_us;
- period = ktime_to_ns(tg->cfs_bandwidth.period);
- burst = tg->cfs_bandwidth.burst;
- if (cfs_quota_us < 0)
- quota = RUNTIME_INF;
- else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC)
- quota = (u64)cfs_quota_us * NSEC_PER_USEC;
- else
- return -EINVAL;
+ cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period);
+ do_div(cfs_period_us, NSEC_PER_USEC);
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
+ return cfs_period_us;
}
static long tg_get_cfs_quota(struct task_group *tg)
@@ -9433,6 +9427,16 @@ static long tg_get_cfs_quota(struct task_group *tg)
return quota_us;
}
+static long tg_get_cfs_burst(struct task_group *tg)
+{
+ u64 burst_us;
+
+ burst_us = tg->cfs_bandwidth.burst;
+ do_div(burst_us, NSEC_PER_USEC);
+
+ return burst_us;
+}
+
static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
{
u64 quota, period, burst;
@@ -9447,14 +9451,20 @@ static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
-static long tg_get_cfs_period(struct task_group *tg)
+static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
{
- u64 cfs_period_us;
+ u64 quota, period, burst;
- cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period);
- do_div(cfs_period_us, NSEC_PER_USEC);
+ period = ktime_to_ns(tg->cfs_bandwidth.period);
+ burst = tg->cfs_bandwidth.burst;
+ if (cfs_quota_us < 0)
+ quota = RUNTIME_INF;
+ else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC)
+ quota = (u64)cfs_quota_us * NSEC_PER_USEC;
+ else
+ return -EINVAL;
- return cfs_period_us;
+ return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us)
@@ -9471,52 +9481,6 @@ static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us)
return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
-static long tg_get_cfs_burst(struct task_group *tg)
-{
- u64 burst_us;
-
- burst_us = tg->cfs_bandwidth.burst;
- do_div(burst_us, NSEC_PER_USEC);
-
- return burst_us;
-}
-
-static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return tg_get_cfs_quota(css_tg(css));
-}
-
-static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css,
- struct cftype *cftype, s64 cfs_quota_us)
-{
- return tg_set_cfs_quota(css_tg(css), cfs_quota_us);
-}
-
-static u64 cpu_cfs_period_read_u64(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return tg_get_cfs_period(css_tg(css));
-}
-
-static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_period_us)
-{
- return tg_set_cfs_period(css_tg(css), cfs_period_us);
-}
-
-static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return tg_get_cfs_burst(css_tg(css));
-}
-
-static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_burst_us)
-{
- return tg_set_cfs_burst(css_tg(css), cfs_burst_us);
-}
-
struct cfs_schedulable_data {
struct task_group *tg;
u64 period, quota;
@@ -9649,6 +9613,42 @@ 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)
+{
+ return tg_get_cfs_period(css_tg(css));
+}
+
+static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return tg_get_cfs_quota(css_tg(css));
+}
+
+static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return tg_get_cfs_burst(css_tg(css));
+}
+
+static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 cfs_period_us)
+{
+ return tg_set_cfs_period(css_tg(css), cfs_period_us);
+}
+
+static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, s64 cfs_quota_us)
+{
+ return tg_set_cfs_quota(css_tg(css), cfs_quota_us);
+}
+
+static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 cfs_burst_us)
+{
+ return tg_set_cfs_burst(css_tg(css), cfs_burst_us);
+}
#endif /* CONFIG_CFS_BANDWIDTH */
#ifdef CONFIG_RT_GROUP_SCHED
@@ -9711,16 +9711,16 @@ static struct cftype cpu_legacy_files[] = {
#endif
#ifdef CONFIG_CFS_BANDWIDTH
{
- .name = "cfs_quota_us",
- .read_s64 = cpu_cfs_quota_read_s64,
- .write_s64 = cpu_cfs_quota_write_s64,
- },
- {
.name = "cfs_period_us",
.read_u64 = cpu_cfs_period_read_u64,
.write_u64 = cpu_cfs_period_write_u64,
},
{
+ .name = "cfs_quota_us",
+ .read_s64 = cpu_cfs_quota_read_s64,
+ .write_s64 = cpu_cfs_quota_write_s64,
+ },
+ {
.name = "cfs_burst_us",
.read_u64 = cpu_cfs_burst_read_u64,
.write_u64 = cpu_cfs_burst_write_u64,
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH 3/4] sched/core: Reorganize cgroup bandwidth control interface file reads
2025-06-14 1:23 [PATCHSET tip/sched/core] sched/core: Reorganize bandwidth control interface handling Tejun Heo
2025-06-14 1:23 ` [PATCH 1/4] sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h Tejun Heo
2025-06-14 1:23 ` [PATCH 2/4] sched/core: Relocate tg_get_cfs_*() and cpu_cfs_*_read_*() Tejun Heo
@ 2025-06-14 1:23 ` Tejun Heo
2025-06-20 9:49 ` [tip: sched/core] " tip-bot2 for Tejun Heo
2025-06-14 1:23 ` [PATCH 4/4] sched/core: Reorganize cgroup bandwidth control interface file writes Tejun Heo
3 siblings, 1 reply; 9+ messages in thread
From: Tejun Heo @ 2025-06-14 1:23 UTC (permalink / raw)
To: mingo, peterz; +Cc: linux-kernel, sched-ext, void, arighi, changwoo, Tejun Heo
- 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>
---
kernel/sched/core.c | 58 +++++++++++++++++++++++++++++++--------------
1 file changed, 40 insertions(+), 18 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index dc9668a6592f..8de93a3bfa27 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -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, "a_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, "a_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 */
--
2.49.0
^ permalink raw reply [flat|nested] 9+ messages in thread* [tip: sched/core] sched/core: Reorganize cgroup bandwidth control interface file reads
2025-06-14 1:23 ` [PATCH 3/4] sched/core: Reorganize cgroup bandwidth control interface file reads Tejun Heo
@ 2025-06-20 9:49 ` tip-bot2 for Tejun Heo
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot2 for Tejun Heo @ 2025-06-20 9:49 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Tejun Heo, Peter Zijlstra (Intel), x86, linux-kernel
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 43e33f53e25687ca870248d1939cfade0164426c
Gitweb: https://git.kernel.org/tip/43e33f53e25687ca870248d1939cfade0164426c
Author: Tejun Heo <tj@kernel.org>
AuthorDate: Fri, 13 Jun 2025 15:23:29 -10:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 18 Jun 2025 13:59:57 +02:00
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
---
kernel/sched/core.c | 58 ++++++++++++++++++++++++++++++--------------
1 file changed, 40 insertions(+), 18 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index dc9668a..8de93a3 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -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, "a_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, "a_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 */
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH 4/4] sched/core: Reorganize cgroup bandwidth control interface file writes
2025-06-14 1:23 [PATCHSET tip/sched/core] sched/core: Reorganize bandwidth control interface handling Tejun Heo
` (2 preceding siblings ...)
2025-06-14 1:23 ` [PATCH 3/4] sched/core: Reorganize cgroup bandwidth control interface file reads Tejun Heo
@ 2025-06-14 1:23 ` Tejun Heo
2025-06-20 9:49 ` [tip: sched/core] " tip-bot2 for Tejun Heo
3 siblings, 1 reply; 9+ messages in thread
From: Tejun Heo @ 2025-06-14 1:23 UTC (permalink / raw)
To: mingo, peterz; +Cc: linux-kernel, sched-ext, void, arighi, changwoo, Tejun Heo
- Move input parameter validation from tg_set_cfs_bandwidth() to the new
outer function tg_set_bandwidth(). The outer function handles parameters
in usecs, validates them and calls tg_set_cfs_bandwidth() which converts
them into nsecs. This matches tg_bandwidth() on the read side.
- max/min_cfs_* consts are now used by tg_set_bandwidth(). Relocate, convert
into usecs and drop "cfs" from the names.
- Reimplement cpu_cfs_{period|quote|burst}_write_*() using tg_bandwidth()
and tg_set_bandwidth() and replace "cfs" in the names with "bw".
- Update cpu_max_write() to use tg_set_bandiwdth(). cpu_period_quota_parse()
is updated to drop nsec conversion accordingly. This aligns the behavior
with cfs_period_quota_print().
- Drop now unused tg_set_cfs_{period|quota|burst}().
- While at it, for consistency, rename default_cfs_period() to
default_bw_period_us() and make it return usecs.
This is to prepare for adding bandwidth control support to sched_ext.
tg_set_bandwidth() will be used as the muxing point. No functional changes
intended.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
kernel/sched/core.c | 205 +++++++++++++++++++++----------------------
kernel/sched/fair.c | 4 +-
kernel/sched/sched.h | 10 +--
3 files changed, 106 insertions(+), 113 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8de93a3bfa27..2f8caa9db78d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9309,47 +9309,23 @@ static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css,
#ifdef CONFIG_CFS_BANDWIDTH
static DEFINE_MUTEX(cfs_constraints_mutex);
-const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */
-static const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */
-/* More than 203 days if BW_SHIFT equals 20. */
-static const u64 max_cfs_runtime = MAX_BW * NSEC_PER_USEC;
-
static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime);
-static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota,
- u64 burst)
+static int tg_set_cfs_bandwidth(struct task_group *tg,
+ u64 period_us, u64 quota_us, u64 burst_us)
{
int i, ret = 0, runtime_enabled, runtime_was_enabled;
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+ u64 period, quota, burst;
- if (tg == &root_task_group)
- return -EINVAL;
-
- /*
- * Ensure we have at some amount of bandwidth every period. This is
- * to prevent reaching a state of large arrears when throttled via
- * entity_tick() resulting in prolonged exit starvation.
- */
- if (quota < min_cfs_quota_period || period < min_cfs_quota_period)
- return -EINVAL;
+ period = (u64)period_us * NSEC_PER_USEC;
- /*
- * Likewise, bound things on the other side by preventing insane quota
- * periods. This also allows us to normalize in computing quota
- * feasibility.
- */
- if (period > max_cfs_quota_period)
- return -EINVAL;
-
- /*
- * Bound quota to defend quota against overflow during bandwidth shift.
- */
- if (quota != RUNTIME_INF && quota > max_cfs_runtime)
- return -EINVAL;
+ if (quota_us == RUNTIME_INF)
+ quota = RUNTIME_INF;
+ else
+ quota = (u64)quota_us * NSEC_PER_USEC;
- if (quota != RUNTIME_INF && (burst > quota ||
- burst + quota > max_cfs_runtime))
- return -EINVAL;
+ burst = (u64)burst_us * NSEC_PER_USEC;
/*
* Prevent race between setting of cfs_rq->runtime_enabled and
@@ -9437,50 +9413,6 @@ static u64 tg_get_cfs_burst(struct task_group *tg)
return burst_us;
}
-static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
-{
- u64 quota, period, burst;
-
- if ((u64)cfs_period_us > U64_MAX / NSEC_PER_USEC)
- return -EINVAL;
-
- period = (u64)cfs_period_us * NSEC_PER_USEC;
- quota = tg->cfs_bandwidth.quota;
- burst = tg->cfs_bandwidth.burst;
-
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
-}
-
-static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
-{
- u64 quota, period, burst;
-
- period = ktime_to_ns(tg->cfs_bandwidth.period);
- burst = tg->cfs_bandwidth.burst;
- if (cfs_quota_us < 0)
- quota = RUNTIME_INF;
- else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC)
- quota = (u64)cfs_quota_us * NSEC_PER_USEC;
- else
- return -EINVAL;
-
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
-}
-
-static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us)
-{
- u64 quota, period, burst;
-
- if ((u64)cfs_burst_us > U64_MAX / NSEC_PER_USEC)
- return -EINVAL;
-
- burst = (u64)cfs_burst_us * NSEC_PER_USEC;
- period = ktime_to_ns(tg->cfs_bandwidth.period);
- quota = tg->cfs_bandwidth.quota;
-
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
-}
-
struct cfs_schedulable_data {
struct task_group *tg;
u64 period, quota;
@@ -9614,6 +9546,11 @@ static int cpu_cfs_local_stat_show(struct seq_file *sf, void *v)
return 0;
}
+const u64 max_bw_quota_period_us = 1 * USEC_PER_SEC; /* 1s */
+static const u64 min_bw_quota_period_us = 1 * USEC_PER_MSEC; /* 1ms */
+/* More than 203 days if BW_SHIFT equals 20. */
+static const u64 max_bw_runtime_us = MAX_BW;
+
static void tg_bandwidth(struct task_group *tg,
u64 *period_us_p, u64 *quota_us_p, u64 *burst_us_p)
{
@@ -9634,6 +9571,50 @@ static u64 cpu_period_read_u64(struct cgroup_subsys_state *css,
return period_us;
}
+static int tg_set_bandwidth(struct task_group *tg,
+ u64 period_us, u64 quota_us, u64 burst_us)
+{
+ const u64 max_usec = U64_MAX / NSEC_PER_USEC;
+
+ if (tg == &root_task_group)
+ return -EINVAL;
+
+ /* Values should survive translation to nsec */
+ if (period_us > max_usec ||
+ (quota_us != RUNTIME_INF && quota_us > max_usec) ||
+ burst_us > max_usec)
+ return -EINVAL;
+
+ /*
+ * Ensure we have some amount of bandwidth every period. This is to
+ * prevent reaching a state of large arrears when throttled via
+ * entity_tick() resulting in prolonged exit starvation.
+ */
+ if (quota_us < min_bw_quota_period_us ||
+ period_us < min_bw_quota_period_us)
+ return -EINVAL;
+
+ /*
+ * Likewise, bound things on the other side by preventing insane quota
+ * periods. This also allows us to normalize in computing quota
+ * feasibility.
+ */
+ if (period_us > max_bw_quota_period_us)
+ return -EINVAL;
+
+ /*
+ * Bound quota to defend quota against overflow during bandwidth shift.
+ */
+ if (quota_us != RUNTIME_INF && quota_us > max_bw_runtime_us)
+ return -EINVAL;
+
+ if (quota_us != RUNTIME_INF && (burst_us > quota_us ||
+ burst_us + quota_us > max_bw_runtime_us))
+ return -EINVAL;
+
+ return tg_set_cfs_bandwidth(tg, period_us, quota_us, burst_us);
+}
+
static s64 cpu_quota_read_s64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
@@ -9652,22 +9633,37 @@ static u64 cpu_burst_read_u64(struct cgroup_subsys_state *css,
return burst_us;
}
-static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_period_us)
+static int cpu_period_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 period_us)
{
- return tg_set_cfs_period(css_tg(css), cfs_period_us);
+ struct task_group *tg = css_tg(css);
+ u64 quota_us, burst_us;
+
+ tg_bandwidth(tg, NULL, "a_us, &burst_us);
+ return tg_set_bandwidth(tg, period_us, quota_us, burst_us);
}
-static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css,
- struct cftype *cftype, s64 cfs_quota_us)
+static int cpu_quota_write_s64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, s64 quota_us)
{
- return tg_set_cfs_quota(css_tg(css), cfs_quota_us);
+ struct task_group *tg = css_tg(css);
+ u64 period_us, burst_us;
+
+ if (quota_us < 0)
+ quota_us = RUNTIME_INF;
+
+ tg_bandwidth(tg, &period_us, NULL, &burst_us);
+ return tg_set_bandwidth(tg, period_us, quota_us, burst_us);
}
-static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_burst_us)
+static int cpu_burst_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 burst_us)
{
- return tg_set_cfs_burst(css_tg(css), cfs_burst_us);
+ struct task_group *tg = css_tg(css);
+ u64 period_us, quota_us;
+
+ tg_bandwidth(tg, &period_us, "a_us, NULL);
+ return tg_set_bandwidth(tg, period_us, quota_us, burst_us);
}
#endif /* CONFIG_CFS_BANDWIDTH */
@@ -9733,17 +9729,17 @@ static struct cftype cpu_legacy_files[] = {
{
.name = "cfs_period_us",
.read_u64 = cpu_period_read_u64,
- .write_u64 = cpu_cfs_period_write_u64,
+ .write_u64 = cpu_period_write_u64,
},
{
.name = "cfs_quota_us",
.read_s64 = cpu_quota_read_s64,
- .write_s64 = cpu_cfs_quota_write_s64,
+ .write_s64 = cpu_quota_write_s64,
},
{
.name = "cfs_burst_us",
.read_u64 = cpu_burst_read_u64,
- .write_u64 = cpu_cfs_burst_write_u64,
+ .write_u64 = cpu_burst_write_u64,
},
{
.name = "stat",
@@ -9940,22 +9936,20 @@ static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
}
/* caller should put the current value in *@periodp before calling */
-static int __maybe_unused cpu_period_quota_parse(char *buf,
- u64 *periodp, u64 *quotap)
+static int __maybe_unused cpu_period_quota_parse(char *buf, u64 *period_us_p,
+ u64 *quota_us_p)
{
char tok[21]; /* U64_MAX */
- if (sscanf(buf, "%20s %llu", tok, periodp) < 1)
+ if (sscanf(buf, "%20s %llu", tok, period_us_p) < 1)
return -EINVAL;
- *periodp *= NSEC_PER_USEC;
-
- if (sscanf(tok, "%llu", quotap))
- *quotap *= NSEC_PER_USEC;
- else if (!strcmp(tok, "max"))
- *quotap = RUNTIME_INF;
- else
- return -EINVAL;
+ if (sscanf(tok, "%llu", quota_us_p) < 1) {
+ if (!strcmp(tok, "max"))
+ *quota_us_p = RUNTIME_INF;
+ else
+ return -EINVAL;
+ }
return 0;
}
@@ -9975,14 +9969,13 @@ static ssize_t cpu_max_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
struct task_group *tg = css_tg(of_css(of));
- u64 period = tg_get_cfs_period(tg);
- u64 burst = tg->cfs_bandwidth.burst;
- u64 quota;
+ u64 period_us, quota_us, burst_us;
int ret;
- ret = cpu_period_quota_parse(buf, &period, "a);
+ tg_bandwidth(tg, &period_us, NULL, &burst_us);
+ ret = cpu_period_quota_parse(buf, &period_us, "a_us);
if (!ret)
- ret = tg_set_cfs_bandwidth(tg, period, quota, burst);
+ ret = tg_set_bandwidth(tg, period_us, quota_us, burst_us);
return ret ?: nbytes;
}
#endif /* CONFIG_CFS_BANDWIDTH */
@@ -10019,7 +10012,7 @@ static struct cftype cpu_files[] = {
.name = "max.burst",
.flags = CFTYPE_NOT_ON_ROOT,
.read_u64 = cpu_burst_read_u64,
- .write_u64 = cpu_cfs_burst_write_u64,
+ .write_u64 = cpu_burst_write_u64,
},
#endif /* CONFIG_CFS_BANDWIDTH */
#ifdef CONFIG_UCLAMP_TASK_GROUP
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 707be4570430..7e2963efe800 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6422,7 +6422,7 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
* to fail.
*/
new = old * 2;
- if (new < max_cfs_quota_period) {
+ if (new < max_bw_quota_period_us * NSEC_PER_USEC) {
cfs_b->period = ns_to_ktime(new);
cfs_b->quota *= 2;
cfs_b->burst *= 2;
@@ -6456,7 +6456,7 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *paren
raw_spin_lock_init(&cfs_b->lock);
cfs_b->runtime = 0;
cfs_b->quota = RUNTIME_INF;
- cfs_b->period = ns_to_ktime(default_cfs_period());
+ cfs_b->period = us_to_ktime(default_bw_period_us());
cfs_b->burst = 0;
cfs_b->hierarchical_quota = parent ? parent->hierarchical_quota : RUNTIME_INF;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index e00b80cd998e..105190b18020 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -403,15 +403,15 @@ static inline bool dl_server_active(struct sched_dl_entity *dl_se)
extern struct list_head task_groups;
#ifdef CONFIG_CFS_BANDWIDTH
-extern const u64 max_cfs_quota_period;
+extern const u64 max_bw_quota_period_us;
/*
- * default period for cfs group bandwidth.
- * default: 0.1s, units: nanoseconds
+ * default period for group bandwidth.
+ * default: 0.1s, units: microseconds
*/
-static inline u64 default_cfs_period(void)
+static inline u64 default_bw_period_us(void)
{
- return 100000000ULL;
+ return 100000ULL;
}
#endif /* CONFIG_CFS_BANDWIDTH */
--
2.49.0
^ permalink raw reply [flat|nested] 9+ messages in thread* [tip: sched/core] sched/core: Reorganize cgroup bandwidth control interface file writes
2025-06-14 1:23 ` [PATCH 4/4] sched/core: Reorganize cgroup bandwidth control interface file writes Tejun Heo
@ 2025-06-20 9:49 ` tip-bot2 for Tejun Heo
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot2 for Tejun Heo @ 2025-06-20 9:49 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Tejun Heo, Peter Zijlstra (Intel), x86, linux-kernel
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 5bc34be478d09c4d16009e665e020ad0fcd0deea
Gitweb: https://git.kernel.org/tip/5bc34be478d09c4d16009e665e020ad0fcd0deea
Author: Tejun Heo <tj@kernel.org>
AuthorDate: Fri, 13 Jun 2025 15:23:30 -10:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 18 Jun 2025 13:59:57 +02:00
sched/core: Reorganize cgroup bandwidth control interface file writes
- Move input parameter validation from tg_set_cfs_bandwidth() to the new
outer function tg_set_bandwidth(). The outer function handles parameters
in usecs, validates them and calls tg_set_cfs_bandwidth() which converts
them into nsecs. This matches tg_bandwidth() on the read side.
- max/min_cfs_* consts are now used by tg_set_bandwidth(). Relocate, convert
into usecs and drop "cfs" from the names.
- Reimplement cpu_cfs_{period|quote|burst}_write_*() using tg_bandwidth()
and tg_set_bandwidth() and replace "cfs" in the names with "bw".
- Update cpu_max_write() to use tg_set_bandiwdth(). cpu_period_quota_parse()
is updated to drop nsec conversion accordingly. This aligns the behavior
with cfs_period_quota_print().
- Drop now unused tg_set_cfs_{period|quota|burst}().
- While at it, for consistency, rename default_cfs_period() to
default_bw_period_us() and make it return usecs.
This is to prepare for adding bandwidth control support to sched_ext.
tg_set_bandwidth() will be used as the muxing point. No functional changes
intended.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250614012346.2358261-5-tj@kernel.org
---
kernel/sched/core.c | 205 ++++++++++++++++++++----------------------
kernel/sched/fair.c | 4 +-
kernel/sched/sched.h | 10 +-
3 files changed, 106 insertions(+), 113 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8de93a3..2f8caa9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9309,47 +9309,23 @@ static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css,
#ifdef CONFIG_CFS_BANDWIDTH
static DEFINE_MUTEX(cfs_constraints_mutex);
-const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */
-static const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */
-/* More than 203 days if BW_SHIFT equals 20. */
-static const u64 max_cfs_runtime = MAX_BW * NSEC_PER_USEC;
-
static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime);
-static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota,
- u64 burst)
+static int tg_set_cfs_bandwidth(struct task_group *tg,
+ u64 period_us, u64 quota_us, u64 burst_us)
{
int i, ret = 0, runtime_enabled, runtime_was_enabled;
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+ u64 period, quota, burst;
- if (tg == &root_task_group)
- return -EINVAL;
-
- /*
- * Ensure we have at some amount of bandwidth every period. This is
- * to prevent reaching a state of large arrears when throttled via
- * entity_tick() resulting in prolonged exit starvation.
- */
- if (quota < min_cfs_quota_period || period < min_cfs_quota_period)
- return -EINVAL;
+ period = (u64)period_us * NSEC_PER_USEC;
- /*
- * Likewise, bound things on the other side by preventing insane quota
- * periods. This also allows us to normalize in computing quota
- * feasibility.
- */
- if (period > max_cfs_quota_period)
- return -EINVAL;
-
- /*
- * Bound quota to defend quota against overflow during bandwidth shift.
- */
- if (quota != RUNTIME_INF && quota > max_cfs_runtime)
- return -EINVAL;
+ if (quota_us == RUNTIME_INF)
+ quota = RUNTIME_INF;
+ else
+ quota = (u64)quota_us * NSEC_PER_USEC;
- if (quota != RUNTIME_INF && (burst > quota ||
- burst + quota > max_cfs_runtime))
- return -EINVAL;
+ burst = (u64)burst_us * NSEC_PER_USEC;
/*
* Prevent race between setting of cfs_rq->runtime_enabled and
@@ -9437,50 +9413,6 @@ static u64 tg_get_cfs_burst(struct task_group *tg)
return burst_us;
}
-static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
-{
- u64 quota, period, burst;
-
- if ((u64)cfs_period_us > U64_MAX / NSEC_PER_USEC)
- return -EINVAL;
-
- period = (u64)cfs_period_us * NSEC_PER_USEC;
- quota = tg->cfs_bandwidth.quota;
- burst = tg->cfs_bandwidth.burst;
-
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
-}
-
-static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
-{
- u64 quota, period, burst;
-
- period = ktime_to_ns(tg->cfs_bandwidth.period);
- burst = tg->cfs_bandwidth.burst;
- if (cfs_quota_us < 0)
- quota = RUNTIME_INF;
- else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC)
- quota = (u64)cfs_quota_us * NSEC_PER_USEC;
- else
- return -EINVAL;
-
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
-}
-
-static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us)
-{
- u64 quota, period, burst;
-
- if ((u64)cfs_burst_us > U64_MAX / NSEC_PER_USEC)
- return -EINVAL;
-
- burst = (u64)cfs_burst_us * NSEC_PER_USEC;
- period = ktime_to_ns(tg->cfs_bandwidth.period);
- quota = tg->cfs_bandwidth.quota;
-
- return tg_set_cfs_bandwidth(tg, period, quota, burst);
-}
-
struct cfs_schedulable_data {
struct task_group *tg;
u64 period, quota;
@@ -9614,6 +9546,11 @@ static int cpu_cfs_local_stat_show(struct seq_file *sf, void *v)
return 0;
}
+const u64 max_bw_quota_period_us = 1 * USEC_PER_SEC; /* 1s */
+static const u64 min_bw_quota_period_us = 1 * USEC_PER_MSEC; /* 1ms */
+/* More than 203 days if BW_SHIFT equals 20. */
+static const u64 max_bw_runtime_us = MAX_BW;
+
static void tg_bandwidth(struct task_group *tg,
u64 *period_us_p, u64 *quota_us_p, u64 *burst_us_p)
{
@@ -9634,6 +9571,50 @@ static u64 cpu_period_read_u64(struct cgroup_subsys_state *css,
return period_us;
}
+static int tg_set_bandwidth(struct task_group *tg,
+ u64 period_us, u64 quota_us, u64 burst_us)
+{
+ const u64 max_usec = U64_MAX / NSEC_PER_USEC;
+
+ if (tg == &root_task_group)
+ return -EINVAL;
+
+ /* Values should survive translation to nsec */
+ if (period_us > max_usec ||
+ (quota_us != RUNTIME_INF && quota_us > max_usec) ||
+ burst_us > max_usec)
+ return -EINVAL;
+
+ /*
+ * Ensure we have some amount of bandwidth every period. This is to
+ * prevent reaching a state of large arrears when throttled via
+ * entity_tick() resulting in prolonged exit starvation.
+ */
+ if (quota_us < min_bw_quota_period_us ||
+ period_us < min_bw_quota_period_us)
+ return -EINVAL;
+
+ /*
+ * Likewise, bound things on the other side by preventing insane quota
+ * periods. This also allows us to normalize in computing quota
+ * feasibility.
+ */
+ if (period_us > max_bw_quota_period_us)
+ return -EINVAL;
+
+ /*
+ * Bound quota to defend quota against overflow during bandwidth shift.
+ */
+ if (quota_us != RUNTIME_INF && quota_us > max_bw_runtime_us)
+ return -EINVAL;
+
+ if (quota_us != RUNTIME_INF && (burst_us > quota_us ||
+ burst_us + quota_us > max_bw_runtime_us))
+ return -EINVAL;
+
+ return tg_set_cfs_bandwidth(tg, period_us, quota_us, burst_us);
+}
+
static s64 cpu_quota_read_s64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
@@ -9652,22 +9633,37 @@ static u64 cpu_burst_read_u64(struct cgroup_subsys_state *css,
return burst_us;
}
-static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_period_us)
+static int cpu_period_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 period_us)
{
- return tg_set_cfs_period(css_tg(css), cfs_period_us);
+ struct task_group *tg = css_tg(css);
+ u64 quota_us, burst_us;
+
+ tg_bandwidth(tg, NULL, "a_us, &burst_us);
+ return tg_set_bandwidth(tg, period_us, quota_us, burst_us);
}
-static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css,
- struct cftype *cftype, s64 cfs_quota_us)
+static int cpu_quota_write_s64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, s64 quota_us)
{
- return tg_set_cfs_quota(css_tg(css), cfs_quota_us);
+ struct task_group *tg = css_tg(css);
+ u64 period_us, burst_us;
+
+ if (quota_us < 0)
+ quota_us = RUNTIME_INF;
+
+ tg_bandwidth(tg, &period_us, NULL, &burst_us);
+ return tg_set_bandwidth(tg, period_us, quota_us, burst_us);
}
-static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css,
- struct cftype *cftype, u64 cfs_burst_us)
+static int cpu_burst_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 burst_us)
{
- return tg_set_cfs_burst(css_tg(css), cfs_burst_us);
+ struct task_group *tg = css_tg(css);
+ u64 period_us, quota_us;
+
+ tg_bandwidth(tg, &period_us, "a_us, NULL);
+ return tg_set_bandwidth(tg, period_us, quota_us, burst_us);
}
#endif /* CONFIG_CFS_BANDWIDTH */
@@ -9733,17 +9729,17 @@ static struct cftype cpu_legacy_files[] = {
{
.name = "cfs_period_us",
.read_u64 = cpu_period_read_u64,
- .write_u64 = cpu_cfs_period_write_u64,
+ .write_u64 = cpu_period_write_u64,
},
{
.name = "cfs_quota_us",
.read_s64 = cpu_quota_read_s64,
- .write_s64 = cpu_cfs_quota_write_s64,
+ .write_s64 = cpu_quota_write_s64,
},
{
.name = "cfs_burst_us",
.read_u64 = cpu_burst_read_u64,
- .write_u64 = cpu_cfs_burst_write_u64,
+ .write_u64 = cpu_burst_write_u64,
},
{
.name = "stat",
@@ -9940,22 +9936,20 @@ static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
}
/* caller should put the current value in *@periodp before calling */
-static int __maybe_unused cpu_period_quota_parse(char *buf,
- u64 *periodp, u64 *quotap)
+static int __maybe_unused cpu_period_quota_parse(char *buf, u64 *period_us_p,
+ u64 *quota_us_p)
{
char tok[21]; /* U64_MAX */
- if (sscanf(buf, "%20s %llu", tok, periodp) < 1)
+ if (sscanf(buf, "%20s %llu", tok, period_us_p) < 1)
return -EINVAL;
- *periodp *= NSEC_PER_USEC;
-
- if (sscanf(tok, "%llu", quotap))
- *quotap *= NSEC_PER_USEC;
- else if (!strcmp(tok, "max"))
- *quotap = RUNTIME_INF;
- else
- return -EINVAL;
+ if (sscanf(tok, "%llu", quota_us_p) < 1) {
+ if (!strcmp(tok, "max"))
+ *quota_us_p = RUNTIME_INF;
+ else
+ return -EINVAL;
+ }
return 0;
}
@@ -9975,14 +9969,13 @@ static ssize_t cpu_max_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
struct task_group *tg = css_tg(of_css(of));
- u64 period = tg_get_cfs_period(tg);
- u64 burst = tg->cfs_bandwidth.burst;
- u64 quota;
+ u64 period_us, quota_us, burst_us;
int ret;
- ret = cpu_period_quota_parse(buf, &period, "a);
+ tg_bandwidth(tg, &period_us, NULL, &burst_us);
+ ret = cpu_period_quota_parse(buf, &period_us, "a_us);
if (!ret)
- ret = tg_set_cfs_bandwidth(tg, period, quota, burst);
+ ret = tg_set_bandwidth(tg, period_us, quota_us, burst_us);
return ret ?: nbytes;
}
#endif /* CONFIG_CFS_BANDWIDTH */
@@ -10019,7 +10012,7 @@ static struct cftype cpu_files[] = {
.name = "max.burst",
.flags = CFTYPE_NOT_ON_ROOT,
.read_u64 = cpu_burst_read_u64,
- .write_u64 = cpu_cfs_burst_write_u64,
+ .write_u64 = cpu_burst_write_u64,
},
#endif /* CONFIG_CFS_BANDWIDTH */
#ifdef CONFIG_UCLAMP_TASK_GROUP
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 707be45..7e2963e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6422,7 +6422,7 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
* to fail.
*/
new = old * 2;
- if (new < max_cfs_quota_period) {
+ if (new < max_bw_quota_period_us * NSEC_PER_USEC) {
cfs_b->period = ns_to_ktime(new);
cfs_b->quota *= 2;
cfs_b->burst *= 2;
@@ -6456,7 +6456,7 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *paren
raw_spin_lock_init(&cfs_b->lock);
cfs_b->runtime = 0;
cfs_b->quota = RUNTIME_INF;
- cfs_b->period = ns_to_ktime(default_cfs_period());
+ cfs_b->period = us_to_ktime(default_bw_period_us());
cfs_b->burst = 0;
cfs_b->hierarchical_quota = parent ? parent->hierarchical_quota : RUNTIME_INF;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index e00b80c..105190b 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -403,15 +403,15 @@ static inline bool dl_server_active(struct sched_dl_entity *dl_se)
extern struct list_head task_groups;
#ifdef CONFIG_CFS_BANDWIDTH
-extern const u64 max_cfs_quota_period;
+extern const u64 max_bw_quota_period_us;
/*
- * default period for cfs group bandwidth.
- * default: 0.1s, units: nanoseconds
+ * default period for group bandwidth.
+ * default: 0.1s, units: microseconds
*/
-static inline u64 default_cfs_period(void)
+static inline u64 default_bw_period_us(void)
{
- return 100000000ULL;
+ return 100000ULL;
}
#endif /* CONFIG_CFS_BANDWIDTH */
^ permalink raw reply [flat|nested] 9+ messages in thread