1909760f5f
On PREEMPT_RT, seqlock_t is transformed to a sleeping lock that do not disable preemption. A seqlock_t reader can thus preempt its write side section and spin for the enter scheduler tick. If that reader belongs to a real-time scheduling class, it can spin forever and the kernel will livelock. To break this livelock possibility on PREEMPT_RT, implement seqlock_t in terms of "seqcount_spinlock_t" instead of plain "seqcount_t". Beside its pure annotational value, this will leverage the existing seqcount_LOCKNAME_T PREEMPT_RT anti-livelock mechanisms, without adding any extra code. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200904153231.11994-6-a.darwish@linutronix.de |
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| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| vdso | ||
| video | ||
| xen | ||