On Mon, 2010-01-18 at 15:41 +0000, Alan Cox wrote:

On Mon, 18 Jan 2010 16:24:07 +0100
Peter Zijlstra [off-list ref] wrote:

quoted

On Mon, 2010-01-18 at 17:19 +0200, Avi Kivity wrote:

quoted

quoted

I would not advice that, just mlock() the text and data you need for the
real-time thread. mlockall() is a really blunt instrument.
   

May not be feasible due to libraries. 

Esp for the real-time case I could advise not to use those libraries
then, since they're clearly not designed for that use case.

In "hard" real time cases an awful lot of libraries have things like
memory allocations in them and don't care about stack growth which can
cause faults and sleeps. The memory allocator if you are running threaded
was not real time priority aware either last time I checked so the
standard libraries are not going to give the behaviour you want unless
you have a proper RT environment, and even then it may be a bit iffy here
and there.

I'm quite aware of that, which is why we recommend people to
pre-allocate, mlock() and pre-fault everything in advance and make sure
the RT thread doesn't touch any data/text outside of that and uses a
limited set of system calls.

You can also do that for stacks using pthread_attr_setstack().



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