Merge tag 'sched-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:

- Fix spurious failures in rseq self-tests (Mark Brown)

- Fix

Merge tag 'sched-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:

- Fix spurious failures in rseq self-tests (Mark Brown)

- Fix rseq rseq::cpu_id_start ABI regression due to TCMalloc's creative
use of the supposedly read-only field

The fix is to introduce a new ABI variant based on a new (larger)
rseq area registration size, to keep the TCMalloc use of rseq
backwards compatible on new kernels (Thomas Gleixner)

- Fix wakeup_preempt_fair() for not waking up task (Vincent Guittot)

- Fix s64 mult overflow in vruntime_eligible() (Zhan Xusheng)

* tag 'sched-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Fix wakeup_preempt_fair() for not waking up task
sched/fair: Fix overflow in vruntime_eligible()
selftests/rseq: Expand for optimized RSEQ ABI v2
rseq: Reenable performance optimizations conditionally
rseq: Implement read only ABI enforcement for optimized RSEQ V2 mode
selftests/rseq: Validate legacy behavior
selftests/rseq: Make registration flexible for legacy and optimized mode
selftests/rseq: Skip tests if time slice extensions are not available
rseq: Revert to historical performance killing behaviour
rseq: Don't advertise time slice extensions if disabled
rseq: Protect rseq_reset() against interrupts
rseq: Set rseq::cpu_id_start to 0 on unregistration
selftests/rseq: Don't run tests with runner scripts outside of the scripts

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selftests/rseq: Validate legacy behavior

The RSEQ legacy mode behavior requires that the ID fields in the rseq
region are unconditionally updated on every context switch and before
signal delivery e

selftests/rseq: Validate legacy behavior

The RSEQ legacy mode behavior requires that the ID fields in the rseq
region are unconditionally updated on every context switch and before
signal delivery even if not required by the ABI specification.

To ensure that this behavior is preserved for legacy users in the future,
add a test which validates that with a sleep() and a signal sent to self.

Provide a run script which prevents GLIBC from registering a RSEQ region,
so that the test can register it's own legacy sized region.

Fixes: 566d8015f7ee ("rseq: Avoid CPU/MM CID updates when no event pending")
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://patch.msgid.link/20260428224427.764705536%40kernel.org
Cc: stable@vger.kernel.org

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