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* [PATCH AUTOSEL 6.12 01/31] sched_ext: selftests/dsp_local_on: Fix sporadic failures
@ 2025-02-18 20:25 Sasha Levin
  2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 02/31] HID: intel-ish-hid: fix the length of MNG_SYNC_FW_CLOCK in doorbell Sasha Levin
                   ` (29 more replies)
  0 siblings, 30 replies; 31+ messages in thread
From: Sasha Levin @ 2025-02-18 20:25 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Tejun Heo, Ihor Solodrai, Andrea Righi, Changwoo Min, Sasha Levin,
	shuah, dvernet, vishalc, linux-kselftest, bpf

From: Tejun Heo <tj@kernel.org>

[ Upstream commit e9fe182772dcb2630964724fd93e9c90b68ea0fd ]

dsp_local_on has several incorrect assumptions, one of which is that
p->nr_cpus_allowed always tracks p->cpus_ptr. This is not true when a task
is scheduled out while migration is disabled - p->cpus_ptr is temporarily
overridden to the previous CPU while p->nr_cpus_allowed remains unchanged.

This led to sporadic test faliures when dsp_local_on_dispatch() tries to put
a migration disabled task to a different CPU. Fix it by keeping the previous
CPU when migration is disabled.

There are SCX schedulers that make use of p->nr_cpus_allowed. They should
also implement explicit handling for p->migration_disabled.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ihor Solodrai <ihor.solodrai@pm.me>
Cc: Andrea Righi <arighi@nvidia.com>
Cc: Changwoo Min <changwoo@igalia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/sched_ext/dsp_local_on.bpf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/sched_ext/dsp_local_on.bpf.c b/tools/testing/selftests/sched_ext/dsp_local_on.bpf.c
index c9a2da0575a0f..eea06decb6f59 100644
--- a/tools/testing/selftests/sched_ext/dsp_local_on.bpf.c
+++ b/tools/testing/selftests/sched_ext/dsp_local_on.bpf.c
@@ -43,7 +43,7 @@ void BPF_STRUCT_OPS(dsp_local_on_dispatch, s32 cpu, struct task_struct *prev)
 	if (!p)
 		return;
 
-	if (p->nr_cpus_allowed == nr_cpus)
+	if (p->nr_cpus_allowed == nr_cpus && !p->migration_disabled)
 		target = bpf_get_prandom_u32() % nr_cpus;
 	else
 		target = scx_bpf_task_cpu(p);
-- 
2.39.5


^ permalink raw reply related	[flat|nested] 31+ messages in thread

end of thread, other threads:[~2025-02-18 20:27 UTC | newest]

Thread overview: 31+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-02-18 20:25 [PATCH AUTOSEL 6.12 01/31] sched_ext: selftests/dsp_local_on: Fix sporadic failures Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 02/31] HID: intel-ish-hid: fix the length of MNG_SYNC_FW_CLOCK in doorbell Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 03/31] HID: intel-ish-hid: Send clock sync message immediately after reset Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 04/31] HID: ignore non-functional sensor in HP 5MP Camera Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 05/31] HID: hid-steam: Fix issues with disabling both gamepad mode and lizard mode Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 06/31] usb: phy: generic: Use proper helper for property detection Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 07/31] HID: intel-ish-hid: ipc: Add Panther Lake PCI device IDs Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 08/31] HID: topre: Fix n-key rollover on Realforce R3S TKL boards Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 09/31] selftests/cgroup: use bash in test_cpuset_v1_hp.sh Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 10/31] HID: hid-apple: Apple Magic Keyboard a3203 USB-C support Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 11/31] HID: apple: fix up the F6 key on the Omoton KB066 keyboard Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 12/31] btrfs: fix two misuses of folio_shift() Sasha Levin
2025-02-18 20:25 ` [PATCH AUTOSEL 6.12 13/31] objtool: Ignore dangling jump table entries Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 14/31] sched: Clarify wake_up_q()'s write to task->wake_q.next Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 15/31] platform/x86: thinkpad_acpi: Fix invalid fan speed on ThinkPad X120e Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 16/31] platform/x86: thinkpad_acpi: Support for V9 DYTC platform profiles Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 17/31] platform/x86: int3472: Use correct type for "polarity", call it gpio_flags Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 18/31] platform/x86: int3472: Call "reset" GPIO "enable" for INT347E Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 19/31] s390/cio: Fix CHPID "configure" attribute caching Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 20/31] thermal/cpufreq_cooling: Remove structure member documentation Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 21/31] um: virt-pci: don't use kmalloc() Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 22/31] um: virtio_uml: use raw spinlock Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 23/31] um: convert irq_lock to " Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 24/31] LoongArch: Fix kernel_page_present() for KPRANGE/XKPRANGE Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 25/31] LoongArch: KVM: Set host with kernel mode when switch to VM mode Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 26/31] arm64: amu: Delay allocating cpumask for AMU FIE support Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 27/31] Xen/swiotlb: mark xen_swiotlb_fixup() __init Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 28/31] Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 29/31] drm/tests: hdmi: Remove redundant assignments Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 30/31] drm/tests: hdmi: Reorder DRM entities variables assignment Sasha Levin
2025-02-18 20:26 ` [PATCH AUTOSEL 6.12 31/31] drm/tests: hdmi: Fix recursive locking Sasha Levin

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