On 01/29/2016 03:04 PM, J. Lewis Muir wrote:
On 1/29/16 3:54 PM, Till Straumann wrote:
These would be my arguments:
- it doesn't make much sense to use RT scheduling w/o memory locking
as this would hurt determinism. Thus, selectively disabling
mlockall() is a poor work-around.
Hi, Till.
True, but I think that just means the toggle is for the wrong thing.
It sounds like there should be a toggle for RT, not mlockall. The RT
toggle would enable both the RT scheduling and the mlockall.
That's what I suggested as an alternative - if you made it all the way to
the bottom of my post ;-). I can see the value of a switch (or envvar)
- but that should control the choice of scheduler together with mlock
(and maybe even other features - such as priority inheritance - which
could be desirable on certain platforms).
The semantics should be "run as a RT app yes or no" with the default
being "no"...
- the code uses these features (RT scheduling + mlockall) *only*
if you give it sufficient privilege to use them. If it has the
privileges then the code assumes you want it to use them.
This is perhaps the real issue: the code assumes it should use
something just because it has sufficient privileges to do so. If I'm
understanding things correctly, if I want to run something as root (or
with certain capabilities) *without* RT, I can't do it. But a toggle
for RT would allow me to do it.
Regards,
Lewis
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- Re: set-user-id root and EPICS 3.15 J. Lewis Muir
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- RE: set-user-id root and EPICS 3.15 Mark Rivers
- Re: set-user-id root and EPICS 3.15 Ralph Lange
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- Re: set-user-id root and EPICS 3.15 Till Straumann
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