Re: [patch] writeback daemons

[Andrew Morton]

Pavel Machek wrote:
> 
> Hi!
> 
> > The number of threads is dynamically managed by a simple
> > demand-driven algorithm.
> 
> So... when we are low on free memory, we try to create more threads... Possible
> deadlock?

Nope.  The number of threads is never allowed to fall below two,
for this very reason.

If the machine is super-low on memory, attempts to start more threads
fail (usually due to the 1-order allocation for the kernel stack).
I've seen this happen.  But the existing two threads are safe,
and that's plenty to get the machine out of trouble.

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