Re: [RFC][PATCH 3/5] add /dev/mem_notify device

From: KOSAKI Motohiro
Date: Tue Jan 15 2008 - 21:44:06 EST


Hi Alan

> > > It also appears there is no way to wait for memory shortages (processes
> > > that can free memory easily) only for memory to start appearing.
> >
> > poll() with never timeout don't fill your requirement?
> > to be honest, maybe I don't understand your afraid yet. sorry.
>
> My misunderstanding. There is in fact no way to wait for memory to become
> available. The poll() method you provide works nicely waiting for
> shortages and responding to them by freeing memory.
>
> It would be interesting to add FASYNC support to this. Some users have
> asked for a signal when memory shortage occurs (as IBM AIX provides
> this). FASYNC support would allow a SIGIO to be delivered from this
> device when memory shortages occurred. Poll as you have implemented is of
> course the easier way for a program to monitor memory and a better
> interface.

OK.
I will challenge implement at mem_notify v5.


- kosaki


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