What about nested qspinlocks?

Posted Aug 21, 2014 13:44 UTC (Thu) by luto (subscriber, #39314)
In reply to: What about nested qspinlocks? by corbet
Parent article: MCS locks and qspinlocks

Why is the number 4 correct?

Process context, software interrupt, hardware interrupt, kprobe breakpoint, krpobe, NMI, MCE. If this can happen, that's seven.

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Posted Jul 20, 2019 17:36 UTC (Sat) by firolwn (guest, #96711) [Link] (1 responses)

According to https://lkml.org/lkml/2019/1/10/799, NMI and MCE should never use spinlock.

There might be a problem in following scenario:
Process context, soft interrupt, hardware interrupt, page fault(e.g. vmalloc), kprobe.

Posted Jul 20, 2019 17:45 UTC (Sat) by firolwn (guest, #96711) [Link]

vmalloc isn't correct. Should be some invalid address in kernel space which triggered a page fault.