Athira Rajeev ef17515a8e selftests/powerpc/pmu/ebb: fix lost_exception_test hang with sched yield change ... commit 79104becf4 ("sched/fair: Forfeit vruntime on yield") changed yield_task_fair() to only bump the deadline when the entity is eligible (vruntime <= avg_vruntime). When the entity is ineligible the yield becomes a complete no-op from scheduling perspective. lost_exception_test calls sched_yield() 100,000 times per iteration to race the EBB exception delivery with a context switch to the eat_cpu companion process. After enough iterations the test process's vruntime races ahead of avg_vruntime (each eligible yield bumps vruntime to deadline, then advances deadline by one slice). Once ineligible, yield_task_fair() does nothing: so the scheduler won't pick the eat_cpu child. No context switch occurs, the PMAO race is never triggered, and ebb_count stays at 0 forever causing the test to hang until timeout. Fix by replacing sched_yield() with nanosleep(0, 1ns). nanosleep() goes through hrtimer_nanosleep() -> do_nanosleep(), which puts the task into TASK_INTERRUPTIBLE and removes it from the run queue entirely. This guarantees the scheduler picks the eat_cpu child, restoring the context-switch guarantee the test requires. The 1ns duration is enough to engage the hrtimer path while keeping the sleep effectively instantaneous; the same race window between PMU overflow and context switch is preserved. Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com> Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20260903074036.63309-1-atrajeev@linux.ibm.com		2026-09-10 08:58:40 +05:30
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crypto/chacha20-s390	crypto: drbg - Fold include/crypto/drbg.h into crypto/drbg.c	2026-05-07 16:09:59 +08:00
cxl	Merge branch 'for-7.3/cxl-misc' into cxl-for-next	2026-08-05 13:23:52 -07:00
fault-injection
ktest	ktest: Add logfile to failure directory	2026-04-20 15:23:13 -04:00
kunit	spi: Updates for v7.3	2026-08-19 09:47:41 -07:00
memblock	kho: make boot time huge page allocation work nicely with KHO	2026-08-23 09:17:38 -07:00
nvdimm	nvdimm: ndtest: remove redundant NULL check before vfree()	2026-07-14 16:12:53 -07:00
radix-tree	maple_tree: change two GFP flags in tests	2026-08-24 18:43:31 -07:00
rbtree
scatterlist
selftests	selftests/powerpc/pmu/ebb: fix lost_exception_test hang with sched yield change	2026-09-10 08:58:40 +05:30
shared	mm/slab: improve kmem_cache_alloc_bulk	2026-06-03 18:20:43 +02:00
vma	mm: fix CONFIG_STACK_GROWSUP typo in tools/testing/vma/include/dup.h	2026-08-24 18:43:12 -07:00
vsock	vsock/test: add test for small packets under pressure	2026-07-21 12:11:06 +02:00