[TUHS] signals and blocked in I/O

Ralph Corderoy ralph at inputplus.co.uk
Sun Dec 3 23:50:18 AEST 2017

Hi Larry,

> The fundamental problem is that they are sleeping waiting for memory
> to be freed.  They are NOT in I/O mode, there is no DMA happening,
> this is main memory, it is not backed by swap, there is no swap.  So
> they are sleeping waiting for the pageout daemon to free some memory.
> It's not going to free their memory because there is no place to stash
> (no swap).  So it's trying to free other memory.


> The real question is where did they go to sleep

Reading through from vm_fault(), is it vm_waitpfault()?

Or, chase down where some of sysctl(3)'s CTL_VM constants are used to
see how their behaviour is effected?

Cheers, Ralph.

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