* [PATCH v2 0/2] sched_ext: Update demo schedulers and selftests for deprecated APIs
@ 2026-03-12 17:55 Cheng-Yang Chou
2026-03-12 17:55 ` [PATCH v2 1/2] sched_ext: Update demo schedulers and selftests to use scx_bpf_task_set_dsq_vtime() Cheng-Yang Chou
2026-03-12 17:55 ` [PATCH v2 2/2] sched_ext: Update demo schedulers and selftests to drop ops.cpu_acquire/release() Cheng-Yang Chou
0 siblings, 2 replies; 6+ messages in thread
From: Cheng-Yang Chou @ 2026-03-12 17:55 UTC (permalink / raw)
To: sched-ext; +Cc: tj, void, arighi, changwoo, jserv, yphbchou0911
Two sets of sched_ext APIs have been deprecated:
- Direct writes to p->scx.dsq_vtime in favor of
scx_bpf_task_set_dsq_vtime()
- ops.cpu_acquire/release() in favor of handling CPU preemption via the
sched_switch tracepoint, as introduced by commit a3f5d4822253
("sched_ext: Allow scx_bpf_reenqueue_local() to be called from
anywhere")
This series updates the demo schedulers (scx_simple, scx_flatcg,
scx_qmap) and selftests (select_cpu_vtime, maximal) to use the new
APIs, keeping them in sync with current best practices.
Patch 1 updates scx_simple, scx_flatcg, and select_cpu_vtime to use
scx_bpf_task_set_dsq_vtime() with scale_by_task_weight.
Patch 2 removes the cpu_acquire/release stubs and the
__COMPAT_scx_bpf_reenqueue_local_from_anywhere() compat guard from
scx_qmap, unconditionally relying on the sched_switch TP. The maximal
selftest and reload_loop test are also fixed to properly attach the
sched_switch tracepoint via bpf_map__set_autoattach() and
maximal__attach(), as both tests use the maximal skeleton.
Changes in v2:
- Use scx_bpf_task_set_dsq_vtime() with scale_by_task_weight instead
of direct assignment and remove redundant bpf_ksym_exists() logic
(Andrea Righi)
- Mention commit a3f5d4822253 ("sched_ext: Allow
scx_bpf_reenqueue_local() to be called from anywhere") in the commit
message to clarify why ops.cpu_acquire/release() are being deprecated
(Andrea Righi)
- Fix maximal.c and reload_loop.c to actually attach the sched_switch
tracepoint by calling bpf_map__set_autoattach() and maximal__attach()
(Andrea Righi)
- Link to v1:
https://lore.kernel.org/all/20260312042001.955675-1-yphbchou0911@gmail.com/
Thanks,
Cheng-Yang
---
Cheng-Yang Chou (2):
sched_ext: Update demo schedulers and selftests to use
scx_bpf_task_set_dsq_vtime()
sched_ext: Update demo schedulers and selftests to drop
ops.cpu_acquire/release()
tools/sched_ext/scx_flatcg.bpf.c | 9 +++++----
tools/sched_ext/scx_qmap.bpf.c | 15 ++-------------
tools/sched_ext/scx_simple.bpf.c | 6 ++++--
tools/testing/selftests/sched_ext/maximal.bpf.c | 15 ++++++---------
tools/testing/selftests/sched_ext/maximal.c | 3 +++
tools/testing/selftests/sched_ext/reload_loop.c | 3 +++
.../selftests/sched_ext/select_cpu_vtime.bpf.c | 7 +++++--
7 files changed, 28 insertions(+), 30 deletions(-)
--
2.48.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v2 1/2] sched_ext: Update demo schedulers and selftests to use scx_bpf_task_set_dsq_vtime() 2026-03-12 17:55 [PATCH v2 0/2] sched_ext: Update demo schedulers and selftests for deprecated APIs Cheng-Yang Chou @ 2026-03-12 17:55 ` Cheng-Yang Chou 2026-03-12 20:57 ` Andrea Righi 2026-03-12 17:55 ` [PATCH v2 2/2] sched_ext: Update demo schedulers and selftests to drop ops.cpu_acquire/release() Cheng-Yang Chou 1 sibling, 1 reply; 6+ messages in thread From: Cheng-Yang Chou @ 2026-03-12 17:55 UTC (permalink / raw) To: sched-ext; +Cc: tj, void, arighi, changwoo, jserv, yphbchou0911 Direct writes to p->scx.dsq_vtime are deprecated in favor of scx_bpf_task_set_dsq_vtime(). Update scx_simple, scx_flatcg, and select_cpu_vtime selftest to use the new kfunc with scale_by_task_weight. Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com> --- tools/sched_ext/scx_flatcg.bpf.c | 9 +++++---- tools/sched_ext/scx_simple.bpf.c | 6 ++++-- tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c | 7 +++++-- 3 files changed, 14 insertions(+), 8 deletions(-) diff --git a/tools/sched_ext/scx_flatcg.bpf.c b/tools/sched_ext/scx_flatcg.bpf.c index a8a9234bb41e..5cb92b4f1635 100644 --- a/tools/sched_ext/scx_flatcg.bpf.c +++ b/tools/sched_ext/scx_flatcg.bpf.c @@ -551,9 +551,10 @@ void BPF_STRUCT_OPS(fcg_stopping, struct task_struct *p, bool runnable) * too much, determine the execution time by taking explicit timestamps * instead of depending on @p->scx.slice. */ + u64 delta = scale_by_task_weight(p, SCX_SLICE_DFL - p->scx.slice); + if (!fifo_sched) - p->scx.dsq_vtime += - (SCX_SLICE_DFL - p->scx.slice) * 100 / p->scx.weight; + scx_bpf_task_set_dsq_vtime(p, p->scx.dsq_vtime + delta); taskc = bpf_task_storage_get(&task_ctx, p, 0, 0); if (!taskc) { @@ -822,7 +823,7 @@ s32 BPF_STRUCT_OPS(fcg_init_task, struct task_struct *p, if (!(cgc = find_cgrp_ctx(args->cgroup))) return -ENOENT; - p->scx.dsq_vtime = cgc->tvtime_now; + scx_bpf_task_set_dsq_vtime(p, cgc->tvtime_now); return 0; } @@ -924,7 +925,7 @@ void BPF_STRUCT_OPS(fcg_cgroup_move, struct task_struct *p, return; delta = time_delta(p->scx.dsq_vtime, from_cgc->tvtime_now); - p->scx.dsq_vtime = to_cgc->tvtime_now + delta; + scx_bpf_task_set_dsq_vtime(p, to_cgc->tvtime_now + delta); } s32 BPF_STRUCT_OPS_SLEEPABLE(fcg_init) diff --git a/tools/sched_ext/scx_simple.bpf.c b/tools/sched_ext/scx_simple.bpf.c index b456bd7cae77..a61a7df81e49 100644 --- a/tools/sched_ext/scx_simple.bpf.c +++ b/tools/sched_ext/scx_simple.bpf.c @@ -121,12 +121,14 @@ void BPF_STRUCT_OPS(simple_stopping, struct task_struct *p, bool runnable) * too much, determine the execution time by taking explicit timestamps * instead of depending on @p->scx.slice. */ - p->scx.dsq_vtime += (SCX_SLICE_DFL - p->scx.slice) * 100 / p->scx.weight; + u64 delta = scale_by_task_weight(p, SCX_SLICE_DFL - p->scx.slice); + + scx_bpf_task_set_dsq_vtime(p, p->scx.dsq_vtime + delta); } void BPF_STRUCT_OPS(simple_enable, struct task_struct *p) { - p->scx.dsq_vtime = vtime_now; + scx_bpf_task_set_dsq_vtime(p, vtime_now); } s32 BPF_STRUCT_OPS_SLEEPABLE(simple_init) diff --git a/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c b/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c index bfcb96cd4954..63e03fe5d983 100644 --- a/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c +++ b/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c @@ -66,12 +66,15 @@ void BPF_STRUCT_OPS(select_cpu_vtime_running, struct task_struct *p) void BPF_STRUCT_OPS(select_cpu_vtime_stopping, struct task_struct *p, bool runnable) { - p->scx.dsq_vtime += (SCX_SLICE_DFL - p->scx.slice) * 100 / p->scx.weight; + u64 delta = scale_by_task_weight(p, SCX_SLICE_DFL - p->scx.slice); + + scx_bpf_task_set_dsq_vtime(p, p->scx.dsq_vtime + delta); + } void BPF_STRUCT_OPS(select_cpu_vtime_enable, struct task_struct *p) { - p->scx.dsq_vtime = vtime_now; + scx_bpf_task_set_dsq_vtime(p, vtime_now); } s32 BPF_STRUCT_OPS_SLEEPABLE(select_cpu_vtime_init) -- 2.48.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] sched_ext: Update demo schedulers and selftests to use scx_bpf_task_set_dsq_vtime() 2026-03-12 17:55 ` [PATCH v2 1/2] sched_ext: Update demo schedulers and selftests to use scx_bpf_task_set_dsq_vtime() Cheng-Yang Chou @ 2026-03-12 20:57 ` Andrea Righi 2026-03-13 1:22 ` Cheng-Yang Chou 0 siblings, 1 reply; 6+ messages in thread From: Andrea Righi @ 2026-03-12 20:57 UTC (permalink / raw) To: Cheng-Yang Chou; +Cc: sched-ext, tj, void, changwoo, jserv Hi Cheng-Yang, On Fri, Mar 13, 2026 at 01:55:26AM +0800, Cheng-Yang Chou wrote: > Direct writes to p->scx.dsq_vtime are deprecated in favor of > scx_bpf_task_set_dsq_vtime(). Update scx_simple, scx_flatcg, and > select_cpu_vtime selftest to use the new kfunc with scale_by_task_weight. Sorry, that's my mistake, we should use scale_by_task_weight_inverse(), not scale_by_task_weight() as I suggested in my previous email. > > Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com> > --- > tools/sched_ext/scx_flatcg.bpf.c | 9 +++++---- > tools/sched_ext/scx_simple.bpf.c | 6 ++++-- > tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c | 7 +++++-- > 3 files changed, 14 insertions(+), 8 deletions(-) > > diff --git a/tools/sched_ext/scx_flatcg.bpf.c b/tools/sched_ext/scx_flatcg.bpf.c > index a8a9234bb41e..5cb92b4f1635 100644 > --- a/tools/sched_ext/scx_flatcg.bpf.c > +++ b/tools/sched_ext/scx_flatcg.bpf.c > @@ -551,9 +551,10 @@ void BPF_STRUCT_OPS(fcg_stopping, struct task_struct *p, bool runnable) > * too much, determine the execution time by taking explicit timestamps > * instead of depending on @p->scx.slice. > */ > + u64 delta = scale_by_task_weight(p, SCX_SLICE_DFL - p->scx.slice); Here. > + > if (!fifo_sched) > - p->scx.dsq_vtime += > - (SCX_SLICE_DFL - p->scx.slice) * 100 / p->scx.weight; > + scx_bpf_task_set_dsq_vtime(p, p->scx.dsq_vtime + delta); > > taskc = bpf_task_storage_get(&task_ctx, p, 0, 0); > if (!taskc) { > @@ -822,7 +823,7 @@ s32 BPF_STRUCT_OPS(fcg_init_task, struct task_struct *p, > if (!(cgc = find_cgrp_ctx(args->cgroup))) > return -ENOENT; > > - p->scx.dsq_vtime = cgc->tvtime_now; > + scx_bpf_task_set_dsq_vtime(p, cgc->tvtime_now); > > return 0; > } > @@ -924,7 +925,7 @@ void BPF_STRUCT_OPS(fcg_cgroup_move, struct task_struct *p, > return; > > delta = time_delta(p->scx.dsq_vtime, from_cgc->tvtime_now); > - p->scx.dsq_vtime = to_cgc->tvtime_now + delta; > + scx_bpf_task_set_dsq_vtime(p, to_cgc->tvtime_now + delta); > } > > s32 BPF_STRUCT_OPS_SLEEPABLE(fcg_init) > diff --git a/tools/sched_ext/scx_simple.bpf.c b/tools/sched_ext/scx_simple.bpf.c > index b456bd7cae77..a61a7df81e49 100644 > --- a/tools/sched_ext/scx_simple.bpf.c > +++ b/tools/sched_ext/scx_simple.bpf.c > @@ -121,12 +121,14 @@ void BPF_STRUCT_OPS(simple_stopping, struct task_struct *p, bool runnable) > * too much, determine the execution time by taking explicit timestamps > * instead of depending on @p->scx.slice. > */ > - p->scx.dsq_vtime += (SCX_SLICE_DFL - p->scx.slice) * 100 / p->scx.weight; > + u64 delta = scale_by_task_weight(p, SCX_SLICE_DFL - p->scx.slice); Here. > + > + scx_bpf_task_set_dsq_vtime(p, p->scx.dsq_vtime + delta); > } > > void BPF_STRUCT_OPS(simple_enable, struct task_struct *p) > { > - p->scx.dsq_vtime = vtime_now; > + scx_bpf_task_set_dsq_vtime(p, vtime_now); > } > > s32 BPF_STRUCT_OPS_SLEEPABLE(simple_init) > diff --git a/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c b/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c > index bfcb96cd4954..63e03fe5d983 100644 > --- a/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c > +++ b/tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c > @@ -66,12 +66,15 @@ void BPF_STRUCT_OPS(select_cpu_vtime_running, struct task_struct *p) > void BPF_STRUCT_OPS(select_cpu_vtime_stopping, struct task_struct *p, > bool runnable) > { > - p->scx.dsq_vtime += (SCX_SLICE_DFL - p->scx.slice) * 100 / p->scx.weight; > + u64 delta = scale_by_task_weight(p, SCX_SLICE_DFL - p->scx.slice); And here. > + > + scx_bpf_task_set_dsq_vtime(p, p->scx.dsq_vtime + delta); > + > } > > void BPF_STRUCT_OPS(select_cpu_vtime_enable, struct task_struct *p) > { > - p->scx.dsq_vtime = vtime_now; > + scx_bpf_task_set_dsq_vtime(p, vtime_now); > } > > s32 BPF_STRUCT_OPS_SLEEPABLE(select_cpu_vtime_init) > -- > 2.48.1 > With s/scale_by_task_weight/scale_by_task_weight_inverse/ Reviewed-by: Andrea Righi <arighi@nvidia.com> Thanks, -Andrea ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] sched_ext: Update demo schedulers and selftests to use scx_bpf_task_set_dsq_vtime() 2026-03-12 20:57 ` Andrea Righi @ 2026-03-13 1:22 ` Cheng-Yang Chou 0 siblings, 0 replies; 6+ messages in thread From: Cheng-Yang Chou @ 2026-03-13 1:22 UTC (permalink / raw) To: Andrea Righi; +Cc: sched-ext, tj, void, changwoo, jserv On Thu, Mar 12, 2026 at 09:57:45PM +0100, Andrea Righi wrote: > Hi Cheng-Yang, > > On Fri, Mar 13, 2026 at 01:55:26AM +0800, Cheng-Yang Chou wrote: > > Direct writes to p->scx.dsq_vtime are deprecated in favor of > > scx_bpf_task_set_dsq_vtime(). Update scx_simple, scx_flatcg, and > > select_cpu_vtime selftest to use the new kfunc with scale_by_task_weight. > > Sorry, that's my mistake, we should use scale_by_task_weight_inverse(), not > scale_by_task_weight() as I suggested in my previous email. I didn't notice it either. I'll send a v3 patch! -- Thanks, Cheng-Yang ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] sched_ext: Update demo schedulers and selftests to drop ops.cpu_acquire/release() 2026-03-12 17:55 [PATCH v2 0/2] sched_ext: Update demo schedulers and selftests for deprecated APIs Cheng-Yang Chou 2026-03-12 17:55 ` [PATCH v2 1/2] sched_ext: Update demo schedulers and selftests to use scx_bpf_task_set_dsq_vtime() Cheng-Yang Chou @ 2026-03-12 17:55 ` Cheng-Yang Chou 2026-03-12 20:58 ` Andrea Righi 1 sibling, 1 reply; 6+ messages in thread From: Cheng-Yang Chou @ 2026-03-12 17:55 UTC (permalink / raw) To: sched-ext; +Cc: tj, void, arighi, changwoo, jserv, yphbchou0911 ops.cpu_acquire/release() are deprecated by commit a3f5d4822253 ("sched_ext: Allow scx_bpf_reenqueue_local() to be called from anywhere") in favor of handling CPU preemption via the sched_switch tracepoint. Update scx_qmap and the maximal selftest to use the new approach. In scx_qmap, remove the cpu_release fallback and the __COMPAT_scx_bpf_reenqueue_local_from_anywhere() compat guard from qmap_sched_switch(), unconditionally handling preemption via the TP. In the maximal selftest, replace the cpu_acquire/release stubs with a minimal sched_switch TP program. Attach all non-struct_ops programs (including the new TP) via maximal__attach() after disabling auto-attach for the maximal_ops struct_ops map, which is managed manually in run(). Apply the same fix to reload_loop, which also uses the maximal skeleton. Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com> --- tools/sched_ext/scx_qmap.bpf.c | 15 ++------------- tools/testing/selftests/sched_ext/maximal.bpf.c | 15 ++++++--------- tools/testing/selftests/sched_ext/maximal.c | 3 +++ tools/testing/selftests/sched_ext/reload_loop.c | 3 +++ 4 files changed, 14 insertions(+), 22 deletions(-) diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c index a4a1b84fe359..a11e27c8de77 100644 --- a/tools/sched_ext/scx_qmap.bpf.c +++ b/tools/sched_ext/scx_qmap.bpf.c @@ -11,8 +11,8 @@ * * - BPF-side queueing using PIDs. * - Sleepable per-task storage allocation using ops.prep_enable(). - * - Using ops.cpu_release() to handle a higher priority scheduling class taking - * the CPU away. + * - Using the sched_switch tracepoint to handle a higher priority scheduling + * class taking the CPU away. * - Core-sched support. * * This scheduler is primarily for demonstration and testing of sched_ext @@ -562,9 +562,6 @@ SEC("tp_btf/sched_switch") int BPF_PROG(qmap_sched_switch, bool preempt, struct task_struct *prev, struct task_struct *next, unsigned long prev_state) { - if (!__COMPAT_scx_bpf_reenqueue_local_from_anywhere()) - return 0; - /* * If @cpu is taken by a higher priority scheduling class, it is no * longer available for executing sched_ext tasks. As we don't want the @@ -586,13 +583,6 @@ int BPF_PROG(qmap_sched_switch, bool preempt, struct task_struct *prev, return 0; } -void BPF_STRUCT_OPS(qmap_cpu_release, s32 cpu, struct scx_cpu_release_args *args) -{ - /* see qmap_sched_switch() to learn how to do this on newer kernels */ - if (!__COMPAT_scx_bpf_reenqueue_local_from_anywhere()) - scx_bpf_reenqueue_local(); -} - s32 BPF_STRUCT_OPS(qmap_init_task, struct task_struct *p, struct scx_init_task_args *args) { @@ -999,7 +989,6 @@ SCX_OPS_DEFINE(qmap_ops, .dispatch = (void *)qmap_dispatch, .tick = (void *)qmap_tick, .core_sched_before = (void *)qmap_core_sched_before, - .cpu_release = (void *)qmap_cpu_release, .init_task = (void *)qmap_init_task, .dump = (void *)qmap_dump, .dump_cpu = (void *)qmap_dump_cpu, diff --git a/tools/testing/selftests/sched_ext/maximal.bpf.c b/tools/testing/selftests/sched_ext/maximal.bpf.c index 01cf4f3da4e0..5858f64313e9 100644 --- a/tools/testing/selftests/sched_ext/maximal.bpf.c +++ b/tools/testing/selftests/sched_ext/maximal.bpf.c @@ -67,13 +67,12 @@ void BPF_STRUCT_OPS(maximal_set_cpumask, struct task_struct *p, void BPF_STRUCT_OPS(maximal_update_idle, s32 cpu, bool idle) {} -void BPF_STRUCT_OPS(maximal_cpu_acquire, s32 cpu, - struct scx_cpu_acquire_args *args) -{} - -void BPF_STRUCT_OPS(maximal_cpu_release, s32 cpu, - struct scx_cpu_release_args *args) -{} +SEC("tp_btf/sched_switch") +int BPF_PROG(maximal_sched_switch, bool preempt, struct task_struct *prev, + struct task_struct *next, unsigned long prev_state) +{ + return 0; +} void BPF_STRUCT_OPS(maximal_cpu_online, s32 cpu) {} @@ -150,8 +149,6 @@ struct sched_ext_ops maximal_ops = { .set_weight = (void *) maximal_set_weight, .set_cpumask = (void *) maximal_set_cpumask, .update_idle = (void *) maximal_update_idle, - .cpu_acquire = (void *) maximal_cpu_acquire, - .cpu_release = (void *) maximal_cpu_release, .cpu_online = (void *) maximal_cpu_online, .cpu_offline = (void *) maximal_cpu_offline, .init_task = (void *) maximal_init_task, diff --git a/tools/testing/selftests/sched_ext/maximal.c b/tools/testing/selftests/sched_ext/maximal.c index c6be50a9941d..1dc369224670 100644 --- a/tools/testing/selftests/sched_ext/maximal.c +++ b/tools/testing/selftests/sched_ext/maximal.c @@ -19,6 +19,9 @@ static enum scx_test_status setup(void **ctx) SCX_ENUM_INIT(skel); SCX_FAIL_IF(maximal__load(skel), "Failed to load skel"); + bpf_map__set_autoattach(skel->maps.maximal_ops, false); + SCX_FAIL_IF(maximal__attach(skel), "Failed to attach skel"); + *ctx = skel; return SCX_TEST_PASS; diff --git a/tools/testing/selftests/sched_ext/reload_loop.c b/tools/testing/selftests/sched_ext/reload_loop.c index 308211d80436..49297b83d748 100644 --- a/tools/testing/selftests/sched_ext/reload_loop.c +++ b/tools/testing/selftests/sched_ext/reload_loop.c @@ -23,6 +23,9 @@ static enum scx_test_status setup(void **ctx) SCX_ENUM_INIT(skel); SCX_FAIL_IF(maximal__load(skel), "Failed to load skel"); + bpf_map__set_autoattach(skel->maps.maximal_ops, false); + SCX_FAIL_IF(maximal__attach(skel), "Failed to attach skel"); + return SCX_TEST_PASS; } -- 2.48.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] sched_ext: Update demo schedulers and selftests to drop ops.cpu_acquire/release() 2026-03-12 17:55 ` [PATCH v2 2/2] sched_ext: Update demo schedulers and selftests to drop ops.cpu_acquire/release() Cheng-Yang Chou @ 2026-03-12 20:58 ` Andrea Righi 0 siblings, 0 replies; 6+ messages in thread From: Andrea Righi @ 2026-03-12 20:58 UTC (permalink / raw) To: Cheng-Yang Chou; +Cc: sched-ext, tj, void, changwoo, jserv On Fri, Mar 13, 2026 at 01:55:27AM +0800, Cheng-Yang Chou wrote: > ops.cpu_acquire/release() are deprecated by commit a3f5d4822253 > ("sched_ext: Allow scx_bpf_reenqueue_local() to be called from > anywhere") in favor of handling CPU preemption via the sched_switch > tracepoint. Update scx_qmap and the maximal selftest to use the new > approach. > > In scx_qmap, remove the cpu_release fallback and the > __COMPAT_scx_bpf_reenqueue_local_from_anywhere() compat guard from > qmap_sched_switch(), unconditionally handling preemption via the TP. > > In the maximal selftest, replace the cpu_acquire/release stubs with a > minimal sched_switch TP program. Attach all non-struct_ops programs > (including the new TP) via maximal__attach() after disabling auto-attach > for the maximal_ops struct_ops map, which is managed manually in run(). > > Apply the same fix to reload_loop, which also uses the maximal skeleton. > > Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com> Looks good! Reviewed-by: Andrea Righi <arighi@nvidia.com> Thanks, -Andrea > --- > tools/sched_ext/scx_qmap.bpf.c | 15 ++------------- > tools/testing/selftests/sched_ext/maximal.bpf.c | 15 ++++++--------- > tools/testing/selftests/sched_ext/maximal.c | 3 +++ > tools/testing/selftests/sched_ext/reload_loop.c | 3 +++ > 4 files changed, 14 insertions(+), 22 deletions(-) > > diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c > index a4a1b84fe359..a11e27c8de77 100644 > --- a/tools/sched_ext/scx_qmap.bpf.c > +++ b/tools/sched_ext/scx_qmap.bpf.c > @@ -11,8 +11,8 @@ > * > * - BPF-side queueing using PIDs. > * - Sleepable per-task storage allocation using ops.prep_enable(). > - * - Using ops.cpu_release() to handle a higher priority scheduling class taking > - * the CPU away. > + * - Using the sched_switch tracepoint to handle a higher priority scheduling > + * class taking the CPU away. > * - Core-sched support. > * > * This scheduler is primarily for demonstration and testing of sched_ext > @@ -562,9 +562,6 @@ SEC("tp_btf/sched_switch") > int BPF_PROG(qmap_sched_switch, bool preempt, struct task_struct *prev, > struct task_struct *next, unsigned long prev_state) > { > - if (!__COMPAT_scx_bpf_reenqueue_local_from_anywhere()) > - return 0; > - > /* > * If @cpu is taken by a higher priority scheduling class, it is no > * longer available for executing sched_ext tasks. As we don't want the > @@ -586,13 +583,6 @@ int BPF_PROG(qmap_sched_switch, bool preempt, struct task_struct *prev, > return 0; > } > > -void BPF_STRUCT_OPS(qmap_cpu_release, s32 cpu, struct scx_cpu_release_args *args) > -{ > - /* see qmap_sched_switch() to learn how to do this on newer kernels */ > - if (!__COMPAT_scx_bpf_reenqueue_local_from_anywhere()) > - scx_bpf_reenqueue_local(); > -} > - > s32 BPF_STRUCT_OPS(qmap_init_task, struct task_struct *p, > struct scx_init_task_args *args) > { > @@ -999,7 +989,6 @@ SCX_OPS_DEFINE(qmap_ops, > .dispatch = (void *)qmap_dispatch, > .tick = (void *)qmap_tick, > .core_sched_before = (void *)qmap_core_sched_before, > - .cpu_release = (void *)qmap_cpu_release, > .init_task = (void *)qmap_init_task, > .dump = (void *)qmap_dump, > .dump_cpu = (void *)qmap_dump_cpu, > diff --git a/tools/testing/selftests/sched_ext/maximal.bpf.c b/tools/testing/selftests/sched_ext/maximal.bpf.c > index 01cf4f3da4e0..5858f64313e9 100644 > --- a/tools/testing/selftests/sched_ext/maximal.bpf.c > +++ b/tools/testing/selftests/sched_ext/maximal.bpf.c > @@ -67,13 +67,12 @@ void BPF_STRUCT_OPS(maximal_set_cpumask, struct task_struct *p, > void BPF_STRUCT_OPS(maximal_update_idle, s32 cpu, bool idle) > {} > > -void BPF_STRUCT_OPS(maximal_cpu_acquire, s32 cpu, > - struct scx_cpu_acquire_args *args) > -{} > - > -void BPF_STRUCT_OPS(maximal_cpu_release, s32 cpu, > - struct scx_cpu_release_args *args) > -{} > +SEC("tp_btf/sched_switch") > +int BPF_PROG(maximal_sched_switch, bool preempt, struct task_struct *prev, > + struct task_struct *next, unsigned long prev_state) > +{ > + return 0; > +} > > void BPF_STRUCT_OPS(maximal_cpu_online, s32 cpu) > {} > @@ -150,8 +149,6 @@ struct sched_ext_ops maximal_ops = { > .set_weight = (void *) maximal_set_weight, > .set_cpumask = (void *) maximal_set_cpumask, > .update_idle = (void *) maximal_update_idle, > - .cpu_acquire = (void *) maximal_cpu_acquire, > - .cpu_release = (void *) maximal_cpu_release, > .cpu_online = (void *) maximal_cpu_online, > .cpu_offline = (void *) maximal_cpu_offline, > .init_task = (void *) maximal_init_task, > diff --git a/tools/testing/selftests/sched_ext/maximal.c b/tools/testing/selftests/sched_ext/maximal.c > index c6be50a9941d..1dc369224670 100644 > --- a/tools/testing/selftests/sched_ext/maximal.c > +++ b/tools/testing/selftests/sched_ext/maximal.c > @@ -19,6 +19,9 @@ static enum scx_test_status setup(void **ctx) > SCX_ENUM_INIT(skel); > SCX_FAIL_IF(maximal__load(skel), "Failed to load skel"); > > + bpf_map__set_autoattach(skel->maps.maximal_ops, false); > + SCX_FAIL_IF(maximal__attach(skel), "Failed to attach skel"); > + > *ctx = skel; > > return SCX_TEST_PASS; > diff --git a/tools/testing/selftests/sched_ext/reload_loop.c b/tools/testing/selftests/sched_ext/reload_loop.c > index 308211d80436..49297b83d748 100644 > --- a/tools/testing/selftests/sched_ext/reload_loop.c > +++ b/tools/testing/selftests/sched_ext/reload_loop.c > @@ -23,6 +23,9 @@ static enum scx_test_status setup(void **ctx) > SCX_ENUM_INIT(skel); > SCX_FAIL_IF(maximal__load(skel), "Failed to load skel"); > > + bpf_map__set_autoattach(skel->maps.maximal_ops, false); > + SCX_FAIL_IF(maximal__attach(skel), "Failed to attach skel"); > + > return SCX_TEST_PASS; > } > > -- > 2.48.1 > ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-03-13 1:22 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-03-12 17:55 [PATCH v2 0/2] sched_ext: Update demo schedulers and selftests for deprecated APIs Cheng-Yang Chou 2026-03-12 17:55 ` [PATCH v2 1/2] sched_ext: Update demo schedulers and selftests to use scx_bpf_task_set_dsq_vtime() Cheng-Yang Chou 2026-03-12 20:57 ` Andrea Righi 2026-03-13 1:22 ` Cheng-Yang Chou 2026-03-12 17:55 ` [PATCH v2 2/2] sched_ext: Update demo schedulers and selftests to drop ops.cpu_acquire/release() Cheng-Yang Chou 2026-03-12 20:58 ` Andrea Righi
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