linux.git/kernel/sched/deadline.c, branch v7.2-rc2 Linux kernel source tree Merge tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip 2026-06-15T09:20:18+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-06-15T09:20:18+00:00 2cbf335f8ccc7a6418159858dc03e36df8e3e5cf Pull scheduler updates from Ingo Molnar: "SMP load-balancing updates: - A large series to introduce infrastructure for cache-aware load balancing, with the goal of co-locating tasks that share data within the same Last Level Cache (LLC) domain. By improving cache locality, the scheduler can reduce cache bouncing and cache misses, ultimately improving data access efficiency. Implemented by Chen Yu and Tim Chen, based on early prototype work by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and Shrikanth Hegde. - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde) Fair scheduler updates: - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing SMT awareness (Andrea Righi, K Prateek Nayak) - A series to optimize cfs_rq and sched_entity allocation for better data locality (Zecheng Li) - A preparatory series to change fair/cgroup scheduling to a single runqueue, without the final change (Peter Zijlstra) - Auto-manage ext/fair dl_server bandwidth (Andrea Righi) - Fix cpu_util runnable_avg arithmetic (Hongyan Xia) - Optimize update_tg_load_avg()'s rate-limiting code (Rik van Riel) - Allow account_cfs_rq_runtime() to throttle current hierarchy (K Prateek Nayak) - Update util_est after updating util_avg during dequeue, to fix the util signal update logic, which reduces signal noise (Vincent Guittot) Scheduler topology updates: - Allow multiple domains to claim sched_domain_shared (K Prateek Nayak) - Add parameter to split LLC (Peter Zijlstra) Core scheduler updates: - Use trace_call__<tp>() to save a static branch (Gabriele Monaco) Scheduler statistics updates: - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation guard (Nicolas Pitre) Deadline scheduler updates: - Reject debugfs dl_server writes for offline CPUs (Andrea Righi) - Fix replenishment logic for non-deferred servers (Yuri Andriaccio) RT scheduling updates: - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt) - Update default bandwidth for real-time tasks to 1.0 (Yuri Andriaccio) Proxy scheduling updates: - A series to implement Optimized Donor Migration for Proxy Execution (John Stultz, Peter Zijlstra) - Various proxy scheduling cleanups and fixes (Peter Zijlstra, K Prateek Nayak) Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi, Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde, Peter Zijlstra, Liang Luo and Yiyang Chen" * tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (91 commits) sched/fair: Fix newidle vs core-sched sched/deadline: Use task_on_rq_migrating() helper sched/core: Combine separate 'else' and 'if' statements sched/fair: Fix cpu_util runnable_avg arithmetic sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime() sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up() sched/fair: Call update_curr() before unthrottling the hierarchy sched/fair: Use throttled_csd_list for local unthrottle sched/fair: Convert cfs bandwidth throttling to use guards sched/fair: Allocate cfs_tg_state with percpu allocator sched/fair: Remove task_group->se pointer array sched/fair: Co-locate cfs_rq and sched_entity in cfs_tg_state sched: restore timer_slack_ns when resetting RT policy on fork MAINTAINERS: Fix spelling mistake in Peter's name sched: Simplify ttwu_runnable() sched/proxy: Remove superfluous clear_task_blocked_in() sched/proxy: Remove PROXY_WAKING sched/proxy: Switch proxy to use p->is_blocked sched/proxy: Only return migrate when needed sched: Be more strict about p->is_blocked ... 
Pull scheduler updates from Ingo Molnar:
 "SMP load-balancing updates:

   - A large series to introduce infrastructure for cache-aware load
     balancing, with the goal of co-locating tasks that share data
     within the same Last Level Cache (LLC) domain. By improving cache
     locality, the scheduler can reduce cache bouncing and cache misses,
     ultimately improving data access efficiency.

     Implemented by Chen Yu and Tim Chen, based on early prototype work
     by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and
     Shrikanth Hegde.

   - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde)

  Fair scheduler updates:

   - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing
     SMT awareness (Andrea Righi, K Prateek Nayak)

   - A series to optimize cfs_rq and sched_entity allocation for better
     data locality (Zecheng Li)

   - A preparatory series to change fair/cgroup scheduling to a single
     runqueue, without the final change (Peter Zijlstra)

   - Auto-manage ext/fair dl_server bandwidth (Andrea Righi)

   - Fix cpu_util runnable_avg arithmetic (Hongyan Xia)

   - Optimize update_tg_load_avg()'s rate-limiting code (Rik van Riel)

   - Allow account_cfs_rq_runtime() to throttle current hierarchy
     (K Prateek Nayak)

   - Update util_est after updating util_avg during dequeue, to fix the
     util signal update logic, which reduces signal noise (Vincent
     Guittot)

  Scheduler topology updates:

   - Allow multiple domains to claim sched_domain_shared (K Prateek
     Nayak)

   - Add parameter to split LLC (Peter Zijlstra)

  Core scheduler updates:

   - Use trace_call__<tp>() to save a static branch (Gabriele Monaco)

  Scheduler statistics updates:

   - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation
     guard (Nicolas Pitre)

  Deadline scheduler updates:

   - Reject debugfs dl_server writes for offline CPUs (Andrea Righi)

   - Fix replenishment logic for non-deferred servers (Yuri Andriaccio)

  RT scheduling updates:

   - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt)

   - Update default bandwidth for real-time tasks to 1.0 (Yuri
     Andriaccio)

  Proxy scheduling updates:

   - A series to implement Optimized Donor Migration for Proxy Execution
     (John Stultz, Peter Zijlstra)

   - Various proxy scheduling cleanups and fixes (Peter Zijlstra,
     K Prateek Nayak)

  Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi,
  Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde,
  Peter Zijlstra, Liang Luo and Yiyang Chen"

* tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (91 commits)
  sched/fair: Fix newidle vs core-sched
  sched/deadline: Use task_on_rq_migrating() helper
  sched/core: Combine separate 'else' and 'if' statements
  sched/fair: Fix cpu_util runnable_avg arithmetic
  sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime()
  sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up()
  sched/fair: Call update_curr() before unthrottling the hierarchy
  sched/fair: Use throttled_csd_list for local unthrottle
  sched/fair: Convert cfs bandwidth throttling to use guards
  sched/fair: Allocate cfs_tg_state with percpu allocator
  sched/fair: Remove task_group->se pointer array
  sched/fair: Co-locate cfs_rq and sched_entity in cfs_tg_state
  sched: restore timer_slack_ns when resetting RT policy on fork
  MAINTAINERS: Fix spelling mistake in Peter's name
  sched: Simplify ttwu_runnable()
  sched/proxy: Remove superfluous clear_task_blocked_in()
  sched/proxy: Remove PROXY_WAKING
  sched/proxy: Switch proxy to use p->is_blocked
  sched/proxy: Only return migrate when needed
  sched: Be more strict about p->is_blocked
  ...
sched/deadline: Use task_on_rq_migrating() helper 2026-06-09T08:28:08+00:00 Liang Luo luoliang@kylinos.cn 2026-06-08T07:55:00+00:00 9ebe5c3c29f6217412ff256134516d4dff0e5624 Replace the open-coded "p->on_rq == TASK_ON_RQ_MIGRATING" comparisons in enqueue_task_dl() and dequeue_task_dl() with the existing task_on_rq_migrating() helper, consistent with the rest of the scheduler code. No functional change. Signed-off-by: Liang Luo <luoliang@kylinos.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://patch.msgid.link/20260608075500.387271-1-luoliang@kylinos.cn 
Replace the open-coded "p->on_rq == TASK_ON_RQ_MIGRATING" comparisons
in enqueue_task_dl() and dequeue_task_dl() with the existing
task_on_rq_migrating() helper, consistent with the rest of the
scheduler code.

No functional change.

Signed-off-by: Liang Luo <luoliang@kylinos.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://patch.msgid.link/20260608075500.387271-1-luoliang@kylinos.cn
sched: deadline: Add dl_rq->curr pointer to address issues with Proxy Exec 2026-06-02T10:26:06+00:00 John Stultz jstultz@google.com 2026-05-12T02:56:13+00:00 cd8e62c85861bcfbbefedce11a6f8eb00c774312 The DL scheduler keeps the current task in the rbtree, since the deadline value isn't usually chagned while the task is runnable. This results in set_next_task() and put_prev_task() being simpler, but unfortunately this causes complexity elsewhere. Specifically when update_curr_dl() updates the deadline, it has to dequeue and then enqueue the task. From put_prev_task_dl(), we first call update_curr_dl(), and then call enqueue_pushable_dl_task(). However, with Proxy Exec this goes awry. Since when a mutex is released, we might wake the waiting rq->donor. This will cause put_prev_task() to be called on the donor to take it off the cpu for return migration. At that point, from put_prev_task_dl() the update_curr_dl() logic will dequeue & enqueue the task, and the enqueue function will call enqueue_pushable_dl_task() (since the task_current() check won't prevent it). Then back up the callstack in put_prev_task_dl() we'll end up calling enqueue_pushable_dl_task() again, tripping the !RB_EMPTY_NODE(&p->pushable_dl_tasks) warning. So to avoid this, use Peter's suggested[1] approach, and add a dl_rq->curr pointer that is set/cleared from set_next_task()/ put_prev_task(), which effectively tracks the rq->donor. We can then use this to avoid adding the active donor to the pushable list from enqueue_task_dl(). [1]: https://lore.kernel.org/lkml/20260304095123.GP606826@noisy.programming.kicks-ass.net/ Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260512025635.2840817-4-jstultz@google.com 
The DL scheduler keeps the current task in the rbtree, since
the deadline value isn't usually chagned while the task is
runnable.

This results in set_next_task() and put_prev_task() being
simpler, but unfortunately this causes complexity elsewhere.

Specifically when update_curr_dl() updates the deadline, it has
to dequeue and then enqueue the task.

From put_prev_task_dl(), we first call update_curr_dl(), and
then call enqueue_pushable_dl_task().

However, with Proxy Exec this goes awry. Since when a mutex is
released, we might wake the waiting rq->donor. This will cause
put_prev_task() to be called on the donor to take it off the
cpu for return migration.

At that point, from put_prev_task_dl() the update_curr_dl()
logic will dequeue & enqueue the task, and the enqueue function
will call enqueue_pushable_dl_task() (since the task_current()
check won't prevent it). Then back up the callstack in
put_prev_task_dl() we'll end up calling
enqueue_pushable_dl_task() again, tripping the
!RB_EMPTY_NODE(&p->pushable_dl_tasks) warning.

So to avoid this, use Peter's suggested[1] approach, and add a
dl_rq->curr pointer that is set/cleared from set_next_task()/
put_prev_task(), which effectively tracks the rq->donor. We can
then use this to avoid adding the active donor to the pushable
list from enqueue_task_dl().

[1]: https://lore.kernel.org/lkml/20260304095123.GP606826@noisy.programming.kicks-ass.net/

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260512025635.2840817-4-jstultz@google.com
sched: deadline: Add some helper variables to cleanup deadline logic 2026-06-02T10:26:06+00:00 John Stultz jstultz@google.com 2026-05-12T02:56:12+00:00 96a6988fb595ab1d77f60b33ea392b2e15b68605 As part of an improvement to handling pushable deadline tasks, Peter suggested this cleanup[1], to use helper values for dl_entity and dl_rq in the enqueue_task_dl() and put_prev_task_dl() functions. There should be no functional change from this patch. To make sure this cleanup change doesn't obscure later logic changes, I've split it into its own patch. [1]: https://lore.kernel.org/lkml/20260304095123.GP606826@noisy.programming.kicks-ass.net/ Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260512025635.2840817-3-jstultz@google.com 
As part of an improvement to handling pushable deadline tasks,
Peter suggested this cleanup[1], to use helper values for
dl_entity and dl_rq in the enqueue_task_dl() and
put_prev_task_dl() functions. There should be no functional
change from this patch.

To make sure this cleanup change doesn't obscure later logic
changes, I've split it into its own patch.

[1]: https://lore.kernel.org/lkml/20260304095123.GP606826@noisy.programming.kicks-ass.net/

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260512025635.2840817-3-jstultz@google.com
sched: Rework prev_balance() to avoid stale prev references 2026-06-02T10:26:06+00:00 John Stultz jstultz@google.com 2026-05-12T02:56:11+00:00 7a3a6bfbd62a2ba3e0ef1e92d6b71abb66890825 Historically, the prev value from __schedule() was the rq->curr. This prev value is passed down through numerous functions, and used in the class scheduler implementations. The fact that prev was on_cpu until the end of __schedule(), meant it was stable across the rq lock drops that the class->balance() implementations often do. However, with proxy-exec, the prev passed to functions called by __schedule() is rq->donor, which may not be the same as rq->curr and may not be on_cpu, this makes the prev value potentially unstable across rq lock drops. A recently found issue with proxy-exec, is when we begin doing return migration from try_to_wake_up(), its possible we may be waking up the rq->donor. When we do this, we proxy_resched_idle() to put_prev_set_next() setting the rq->donor to rq->idle, allowing the rq->donor to be return migrated and allowed to run. This however runs into trouble, as on another cpu we might be in the middle of calling __schedule(). Conceptually the rq lock is held for the majority of the time, but in calling prev_balance() its possible the class->balance() handler call may briefly drop the rq lock. This opens a window for try_to_wake_up() to wake and return migrate the rq->donor before the class logic reacquires the rq lock. Unfortunately prev_balance() pass in a prev argument, to which we pass rq->donor. However this prev value can now become stale and incorrect across a rq lock drop. So, to correct this, rework the prev_balance() call so that it does not take a "prev" argument. Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260512025635.2840817-2-jstultz@google.com 
Historically, the prev value from __schedule() was the rq->curr.
This prev value is passed down through numerous functions, and
used in the class scheduler implementations. The fact that
prev was on_cpu until the end of __schedule(), meant it was
stable across the rq lock drops that the class->balance()
implementations often do.

However, with proxy-exec, the prev passed to functions called
by __schedule() is rq->donor, which may not be the same as
rq->curr and may not be on_cpu, this makes the prev value
potentially unstable across rq lock drops.

A recently found issue with proxy-exec, is when we begin doing
return migration from try_to_wake_up(), its possible we may be
waking up the rq->donor.  When we do this, we proxy_resched_idle()
to put_prev_set_next() setting the rq->donor to rq->idle, allowing
the rq->donor to be return migrated and allowed to run.

This however runs into trouble, as on another cpu we might be in
the middle of calling __schedule(). Conceptually the rq lock is
held for the majority of the time, but in calling prev_balance()
its possible the class->balance() handler call may briefly drop the rq lock.
This opens a window for try_to_wake_up() to wake and return migrate the
rq->donor before the class logic reacquires the rq lock.

Unfortunately prev_balance() pass in a prev argument, to which we pass
rq->donor. However this prev value can now become stale and incorrect across a
rq lock drop.

So, to correct this, rework the prev_balance() call so that it does not take a
"prev" argument.

Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260512025635.2840817-2-jstultz@google.com
sched_ext: Auto-register/unregister dl_server reservations 2026-05-29T10:43:15+00:00 Andrea Righi arighi@nvidia.com 2026-05-26T16:42:48+00:00 e7b63427fdb4977621d69085a97272c8856644fe Commit cd959a3562050d ("sched_ext: Add a DL server for sched_ext tasks") introduced an ext_server deadline server to protect sched_ext tasks from fair/RT starvation, mirroring the existing fair_server. Currently, both servers reserve their 50ms/1000ms bandwidth at boot, regardless of whether a BPF scheduler is loaded. Unused bandwidth is still reclaimed at runtime by other classes, but the static reservation prevents the RT class from implicitly using that headroom when one of the two classes is guaranteed to be empty. A sysadmin can work around this by writing /sys/kernel/debug/sched/{fair,ext}_server/cpu*/runtime, but that requires manual action and not all systems expose debugfs. A better approach is to make server bandwidth reservations dynamic: only the scheduling policy that is currently active should register its reservation, while the inactive one should not artificially hold capacity (keeping both reservations only when the BPF scheduler is running in partial mode): +---------------------------------------------+-------------+------------+ | BPF scheduler state | fair server | ext server | +---------------------------------------------+-------------+------------+ | not loaded (default boot) | reserved | none | | loaded full mode (!SCX_OPS_SWITCH_PARTIAL) | none | reserved | | loaded partial mode (SCX_OPS_SWITCH_PARTIAL)| reserved | reserved | +---------------------------------------------+-------------+------------+ To achieve this, introduce an "attached/detached" state for each deadline server, so the kernel can decide whether a server's bandwidth should be accounted in global bandwidth tracking. At boot, the system starts with only the fair server contributing to bandwidth accounting. When a BPF scheduler is enabled, the ext server is attached and may replace or complement the fair server depending on whether full or partial mode is used. When sched_ext is disabled, the system restores the previous deadline bandwidth values and behavior. The transition logic ensures that switching between scheduling modes is consistent and reversible, without losing runtime configuration or requiring manual intervention. Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://patch.msgid.link/20260526164420.638711-2-arighi@nvidia.com 
Commit cd959a3562050d ("sched_ext: Add a DL server for sched_ext tasks")
introduced an ext_server deadline server to protect sched_ext tasks from
fair/RT starvation, mirroring the existing fair_server.

Currently, both servers reserve their 50ms/1000ms bandwidth at boot,
regardless of whether a BPF scheduler is loaded. Unused bandwidth is
still reclaimed at runtime by other classes, but the static reservation
prevents the RT class from implicitly using that headroom when one of
the two classes is guaranteed to be empty.

A sysadmin can work around this by writing
/sys/kernel/debug/sched/{fair,ext}_server/cpu*/runtime, but that
requires manual action and not all systems expose debugfs.

A better approach is to make server bandwidth reservations dynamic: only
the scheduling policy that is currently active should register its
reservation, while the inactive one should not artificially hold
capacity (keeping both reservations only when the BPF scheduler is
running in partial mode):

 +---------------------------------------------+-------------+------------+
 | BPF scheduler state                         | fair server | ext server |
 +---------------------------------------------+-------------+------------+
 | not loaded (default boot)                   | reserved    | none       |
 | loaded full mode (!SCX_OPS_SWITCH_PARTIAL)  | none        | reserved   |
 | loaded partial mode (SCX_OPS_SWITCH_PARTIAL)| reserved    | reserved   |
 +---------------------------------------------+-------------+------------+

To achieve this, introduce an "attached/detached" state for each
deadline server, so the kernel can decide whether a server's bandwidth
should be accounted in global bandwidth tracking.

At boot, the system starts with only the fair server contributing to
bandwidth accounting. When a BPF scheduler is enabled, the ext server is
attached and may replace or complement the fair server depending on
whether full or partial mode is used. When sched_ext is disabled, the
system restores the previous deadline bandwidth values and behavior.

The transition logic ensures that switching between scheduling modes is
consistent and reversible, without losing runtime configuration or
requiring manual intervention.

Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260526164420.638711-2-arighi@nvidia.com
sched/deadline: Fix replenishment logic for non-deferred servers 2026-05-19T10:17:35+00:00 Yuri Andriaccio yurand2000@gmail.com 2026-04-30T21:38:05+00:00 eecd5e117cfa63a353f4c69fdcea5d9b14af698e Enqueue and replenish non-deferred deadline servers when their runtime is exhausted and the replenishment timer could not be started because it is too close to the wake-up instant. Signed-off-by: Yuri Andriaccio <yurand2000@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260430213835.62217-2-yurand2000@gmail.com 
Enqueue and replenish non-deferred deadline servers when their runtime is
exhausted and the replenishment timer could not be started because it is
too close to the wake-up instant.

Signed-off-by: Yuri Andriaccio <yurand2000@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260430213835.62217-2-yurand2000@gmail.com
cgroup/cpuset: Reserve DL bandwidth only for root-domain moves 2026-05-11T20:27:14+00:00 Guopeng Zhang zhangguopeng@kylinos.cn 2026-05-09T10:20:31+00:00 5dd74441cbf42c22e874450eb6a6bbb19390a216 cpuset_can_attach() currently adds the bandwidth of all migrating SCHED_DEADLINE tasks to sum_migrate_dl_bw. If the source and destination cpuset effective CPU masks do not overlap, the whole sum is then reserved in the destination root domain. set_cpus_allowed_dl(), however, subtracts bandwidth from the source root domain only when the affinity change really moves the task between root domains. A DL task can move between cpusets that are still in the same root domain, so including that task in sum_migrate_dl_bw can reserve destination bandwidth without a matching source-side subtraction. Share the root-domain move test with set_cpus_allowed_dl(). Keep nr_migrate_dl_tasks counting all migrating deadline tasks for cpuset DL task accounting, but add to sum_migrate_dl_bw only for tasks that need a root-domain bandwidth move. Keep using the destination cpuset effective CPU mask and leave the broader can_attach()/attach() transaction model unchanged. Fixes: 2ef269ef1ac0 ("cgroup/cpuset: Free DL BW in case can_attach() fails") Cc: stable@vger.kernel.org # v6.10+ Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn> Reviewed-by: Waiman Long <longman@redhat.com> Acked-by: Juri Lelli <juri.lelli@redhat.com> Tested-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
cpuset_can_attach() currently adds the bandwidth of all migrating
SCHED_DEADLINE tasks to sum_migrate_dl_bw. If the source and destination
cpuset effective CPU masks do not overlap, the whole sum is then
reserved in the destination root domain.

set_cpus_allowed_dl(), however, subtracts bandwidth from the source
root domain only when the affinity change really moves the task between
root domains. A DL task can move between cpusets that are still in the
same root domain, so including that task in sum_migrate_dl_bw can reserve
destination bandwidth without a matching source-side subtraction.

Share the root-domain move test with set_cpus_allowed_dl(). Keep
nr_migrate_dl_tasks counting all migrating deadline tasks for cpuset DL
task accounting, but add to sum_migrate_dl_bw only for tasks that need a
root-domain bandwidth move. Keep using the destination cpuset effective
CPU mask and leave the broader can_attach()/attach() transaction model
unchanged.

Fixes: 2ef269ef1ac0 ("cgroup/cpuset: Free DL BW in case can_attach() fails")
Cc: stable@vger.kernel.org # v6.10+
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Waiman Long <longman@redhat.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Merge tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 2026-04-16T00:15:18+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-04-16T00:15:18+00:00 fdbfee9fc56e13a1307868829d438ad66ab308a4 Pull runtime verification updates from Steven Rostedt: - Refactor da_monitor header to share handlers across monitor types No functional changes, only less code duplication. - Add Hybrid Automata model class Add a new model class that extends deterministic automata by adding constraints on transitions and states. Those constraints can take into account wall-clock time and as such allow RV monitor to make assertions on real time. Add documentation and code generation scripts. - Add stall monitor as hybrid automaton example Add a monitor that triggers a violation when a task is stalling as an example of automaton working with real time variables. - Convert the opid monitor to a hybrid automaton The opid monitor can be heavily simplified if written as a hybrid automaton: instead of tracking preempt and interrupt enable/disable events, it can just run constraints on the preemption/interrupt states when events like wakeup and need_resched verify. - Add support for per-object monitors in DA/HA Allow writing deterministic and hybrid automata monitors for generic objects (e.g. any struct), by exploiting a hash table where objects are saved. This allows to track more than just tasks in RV. For instance it will be used to track deadline entities in deadline monitors. - Add deadline tracepoints and move some deadline utilities Prepare the ground for deadline monitors by defining events and exporting helpers. - Add nomiss deadline monitor Add first example of deadline monitor asserting all entities complete before their deadline. - Improve rvgen error handling Introduce AutomataError exception class and better handle expected exceptions while showing a backtrace for unexpected ones. - Improve python code quality in rvgen Refactor the rvgen generation scripts to align with python best practices: use f-strings instead of %, use len() instead of __len__(), remove semicolons, use context managers for file operations, fix whitespace violations, extract magic strings into constants, remove unused imports and methods. - Fix small bugs in rvgen The generator scripts presented some corner case bugs: logical error in validating what a correct dot file looks like, fix an isinstance() check, enforce a dot file has an initial state, fix type annotations and typos in comments. - rvgen refactoring Refactor automata.py to use iterator-based parsing and handle required arguments directly in argparse. - Allow epoll in rtapp-sleep monitor The epoll_wait call is now rt-friendly so it should be allowed in the sleep monitor as a valid sleep method. * tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (32 commits) rv: Allow epoll in rtapp-sleep monitor rv/rvgen: fix _fill_states() return type annotation rv/rvgen: fix unbound loop variable warning rv/rvgen: enforce presence of initial state rv/rvgen: extract node marker string to class constant rv/rvgen: fix isinstance check in Variable.expand() rv/rvgen: make monitor arguments required in rvgen rv/rvgen: remove unused __get_main_name method rv/rvgen: remove unused sys import from dot2c rv/rvgen: refactor automata.py to use iterator-based parsing rv/rvgen: use class constant for init marker rv/rvgen: fix DOT file validation logic error rv/rvgen: fix PEP 8 whitespace violations rv/rvgen: fix typos in automata and generator docstring and comments rv/rvgen: use context managers for file operations rv/rvgen: remove unnecessary semicolons rv/rvgen: replace __len__() calls with len() rv/rvgen: replace % string formatting with f-strings rv/rvgen: remove bare except clauses in generator rv/rvgen: introduce AutomataError exception class ... 
Pull runtime verification updates from Steven Rostedt:

 - Refactor da_monitor header to share handlers across monitor types

   No functional changes, only less code duplication.

 - Add Hybrid Automata model class

   Add a new model class that extends deterministic automata by adding
   constraints on transitions and states. Those constraints can take
   into account wall-clock time and as such allow RV monitor to make
   assertions on real time. Add documentation and code generation
   scripts.

 - Add stall monitor as hybrid automaton example

   Add a monitor that triggers a violation when a task is stalling as an
   example of automaton working with real time variables.

 - Convert the opid monitor to a hybrid automaton

   The opid monitor can be heavily simplified if written as a hybrid
   automaton: instead of tracking preempt and interrupt enable/disable
   events, it can just run constraints on the preemption/interrupt
   states when events like wakeup and need_resched verify.

 - Add support for per-object monitors in DA/HA

   Allow writing deterministic and hybrid automata monitors for generic
   objects (e.g. any struct), by exploiting a hash table where objects
   are saved. This allows to track more than just tasks in RV. For
   instance it will be used to track deadline entities in deadline
   monitors.

 - Add deadline tracepoints and move some deadline utilities

   Prepare the ground for deadline monitors by defining events and
   exporting helpers.

 - Add nomiss deadline monitor

   Add first example of deadline monitor asserting all entities complete
   before their deadline.

 - Improve rvgen error handling

   Introduce AutomataError exception class and better handle expected
   exceptions while showing a backtrace for unexpected ones.

 - Improve python code quality in rvgen

   Refactor the rvgen generation scripts to align with python best
   practices: use f-strings instead of %, use len() instead of
   __len__(), remove semicolons, use context managers for file
   operations, fix whitespace violations, extract magic strings into
   constants, remove unused imports and methods.

 - Fix small bugs in rvgen

   The generator scripts presented some corner case bugs: logical error
   in validating what a correct dot file looks like, fix an isinstance()
   check, enforce a dot file has an initial state, fix type annotations
   and typos in comments.

 - rvgen refactoring

   Refactor automata.py to use iterator-based parsing and handle
   required arguments directly in argparse.

 - Allow epoll in rtapp-sleep monitor

   The epoll_wait call is now rt-friendly so it should be allowed in the
   sleep monitor as a valid sleep method.

* tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (32 commits)
  rv: Allow epoll in rtapp-sleep monitor
  rv/rvgen: fix _fill_states() return type annotation
  rv/rvgen: fix unbound loop variable warning
  rv/rvgen: enforce presence of initial state
  rv/rvgen: extract node marker string to class constant
  rv/rvgen: fix isinstance check in Variable.expand()
  rv/rvgen: make monitor arguments required in rvgen
  rv/rvgen: remove unused __get_main_name method
  rv/rvgen: remove unused sys import from dot2c
  rv/rvgen: refactor automata.py to use iterator-based parsing
  rv/rvgen: use class constant for init marker
  rv/rvgen: fix DOT file validation logic error
  rv/rvgen: fix PEP 8 whitespace violations
  rv/rvgen: fix typos in automata and generator docstring and comments
  rv/rvgen: use context managers for file operations
  rv/rvgen: remove unnecessary semicolons
  rv/rvgen: replace __len__() calls with len()
  rv/rvgen: replace % string formatting with f-strings
  rv/rvgen: remove bare except clauses in generator
  rv/rvgen: introduce AutomataError exception class
  ...
Merge tag 'sched-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2026-04-14T20:33:36+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-04-14T20:33:36+00:00 1c3b68f0d55b5932eb38eda602a61aec6d6f5e5e Pull scheduler updates from Ingo Molnar: "Fair scheduling updates: - Skip SCHED_IDLE rq for SCHED_IDLE tasks (Christian Loehle) - Remove superfluous rcu_read_lock() in the wakeup path (K Prateek Nayak) - Simplify the entry condition for update_idle_cpu_scan() (K Prateek Nayak) - Simplify SIS_UTIL handling in select_idle_cpu() (K Prateek Nayak) - Avoid overflow in enqueue_entity() (K Prateek Nayak) - Update overutilized detection (Vincent Guittot) - Prevent negative lag increase during delayed dequeue (Vincent Guittot) - Clear buddies for preempt_short (Vincent Guittot) - Implement more complex proportional newidle balance (Peter Zijlstra) - Increase weight bits for avg_vruntime (Peter Zijlstra) - Use full weight to __calc_delta() (Peter Zijlstra) RT and DL scheduling updates: - Fix incorrect schedstats for rt and dl thread (Dengjun Su) - Skip group schedulable check with rt_group_sched=0 (Michal Koutný) - Move group schedulability check to sched_rt_global_validate() (Michal Koutný) - Add reporting of runtime left & abs deadline to sched_getattr() for DEADLINE tasks (Tommaso Cucinotta) Scheduling topology updates by K Prateek Nayak: - Compute sd_weight considering cpuset partitions - Extract "imb_numa_nr" calculation into a separate helper - Allocate per-CPU sched_domain_shared in s_data - Switch to assigning "sd->shared" from s_data - Remove sched_domain_shared allocation with sd_data Energy-aware scheduling updates: - Filter false overloaded_group case for EAS (Vincent Guittot) - PM: EM: Switch to rcu_dereference_all() in wakeup path (Dietmar Eggemann) Infrastructure updates: - Replace use of system_unbound_wq with system_dfl_wq (Marco Crivellari) Proxy scheduling updates by John Stultz: - Make class_schedulers avoid pushing current, and get rid of proxy_tag_curr() - Minimise repeated sched_proxy_exec() checking - Fix potentially missing balancing with Proxy Exec - Fix and improve task::blocked_on et al handling - Add assert_balance_callbacks_empty() helper - Add logic to zap balancing callbacks if we pick again - Move attach_one_task() and attach_task() helpers to sched.h - Handle blocked-waiter migration (and return migration) - Add K Prateek Nayak to scheduler reviewers for proxy execution Misc cleanups and fixes by John Stultz, Joseph Salisbury, Peter Zijlstra, K Prateek Nayak, Michal Koutný, Randy Dunlap, Shrikanth Hegde, Vincent Guittot, Zhan Xusheng, Xie Yuanbin and Vincent Guittot" * tag 'sched-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) sched/eevdf: Clear buddies for preempt_short sched/rt: Cleanup global RT bandwidth functions sched/rt: Move group schedulability check to sched_rt_global_validate() sched/rt: Skip group schedulable check with rt_group_sched=0 sched/fair: Avoid overflow in enqueue_entity() sched: Use u64 for bandwidth ratio calculations sched/fair: Prevent negative lag increase during delayed dequeue sched/fair: Use sched_energy_enabled() sched: Handle blocked-waiter migration (and return migration) sched: Move attach_one_task and attach_task helpers to sched.h sched: Add logic to zap balance callbacks if we pick again sched: Add assert_balance_callbacks_empty helper sched/locking: Add special p->blocked_on==PROXY_WAKING value for proxy return-migration sched: Fix modifying donor->blocked on without proper locking locking: Add task::blocked_lock to serialize blocked_on state sched: Fix potentially missing balancing with Proxy Exec sched: Minimise repeated sched_proxy_exec() checking sched: Make class_schedulers avoid pushing current, and get rid of proxy_tag_curr() MAINTAINERS: Add K Prateek Nayak to scheduler reviewers sched/core: Get this cpu once in ttwu_queue_cond() ... 
Pull scheduler updates from Ingo Molnar:
 "Fair scheduling updates:
   - Skip SCHED_IDLE rq for SCHED_IDLE tasks (Christian Loehle)
   - Remove superfluous rcu_read_lock() in the wakeup path (K Prateek Nayak)
   - Simplify the entry condition for update_idle_cpu_scan() (K Prateek Nayak)
   - Simplify SIS_UTIL handling in select_idle_cpu() (K Prateek Nayak)
   - Avoid overflow in enqueue_entity() (K Prateek Nayak)
   - Update overutilized detection (Vincent Guittot)
   - Prevent negative lag increase during delayed dequeue (Vincent Guittot)
   - Clear buddies for preempt_short (Vincent Guittot)
   - Implement more complex proportional newidle balance (Peter Zijlstra)
   - Increase weight bits for avg_vruntime (Peter Zijlstra)
   - Use full weight to __calc_delta() (Peter Zijlstra)

  RT and DL scheduling updates:
   - Fix incorrect schedstats for rt and dl thread (Dengjun Su)
   - Skip group schedulable check with rt_group_sched=0 (Michal Koutný)
   - Move group schedulability check to sched_rt_global_validate()
     (Michal Koutný)
   - Add reporting of runtime left & abs deadline to sched_getattr()
     for DEADLINE tasks (Tommaso Cucinotta)

  Scheduling topology updates by K Prateek Nayak:
   - Compute sd_weight considering cpuset partitions
   - Extract "imb_numa_nr" calculation into a separate helper
   - Allocate per-CPU sched_domain_shared in s_data
   - Switch to assigning "sd->shared" from s_data
   - Remove sched_domain_shared allocation with sd_data

  Energy-aware scheduling updates:
   - Filter false overloaded_group case for EAS (Vincent Guittot)
   - PM: EM: Switch to rcu_dereference_all() in wakeup path
     (Dietmar Eggemann)

  Infrastructure updates:
   - Replace use of system_unbound_wq with system_dfl_wq (Marco Crivellari)

  Proxy scheduling updates by John Stultz:
   - Make class_schedulers avoid pushing current, and get rid of proxy_tag_curr()
   - Minimise repeated sched_proxy_exec() checking
   - Fix potentially missing balancing with Proxy Exec
   - Fix and improve task::blocked_on et al handling
   - Add assert_balance_callbacks_empty() helper
   - Add logic to zap balancing callbacks if we pick again
   - Move attach_one_task() and attach_task() helpers to sched.h
   - Handle blocked-waiter migration (and return migration)
   - Add K Prateek Nayak to scheduler reviewers for proxy execution

  Misc cleanups and fixes by John Stultz, Joseph Salisbury, Peter
  Zijlstra, K Prateek Nayak, Michal Koutný, Randy Dunlap, Shrikanth
  Hegde, Vincent Guittot, Zhan Xusheng, Xie Yuanbin and Vincent Guittot"

* tag 'sched-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  sched/eevdf: Clear buddies for preempt_short
  sched/rt: Cleanup global RT bandwidth functions
  sched/rt: Move group schedulability check to sched_rt_global_validate()
  sched/rt: Skip group schedulable check with rt_group_sched=0
  sched/fair: Avoid overflow in enqueue_entity()
  sched: Use u64 for bandwidth ratio calculations
  sched/fair: Prevent negative lag increase during delayed dequeue
  sched/fair: Use sched_energy_enabled()
  sched: Handle blocked-waiter migration (and return migration)
  sched: Move attach_one_task and attach_task helpers to sched.h
  sched: Add logic to zap balance callbacks if we pick again
  sched: Add assert_balance_callbacks_empty helper
  sched/locking: Add special p->blocked_on==PROXY_WAKING value for proxy return-migration
  sched: Fix modifying donor->blocked on without proper locking
  locking: Add task::blocked_lock to serialize blocked_on state
  sched: Fix potentially missing balancing with Proxy Exec
  sched: Minimise repeated sched_proxy_exec() checking
  sched: Make class_schedulers avoid pushing current, and get rid of proxy_tag_curr()
  MAINTAINERS: Add K Prateek Nayak to scheduler reviewers
  sched/core: Get this cpu once in ttwu_queue_cond()
  ...