Messages in this thread | | | Date | Fri, 28 Jun 2013 11:55:47 -0700 | From | Anton Vorontsov <> | Subject | Re: [PATCH v2] vmpressure: implement strict mode |
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On Fri, Jun 28, 2013 at 02:45:07PM -0400, Luiz Capitulino wrote: > On Fri, 28 Jun 2013 10:09:17 -0700 > Anton Vorontsov <anton@enomsg.org> wrote: > > > So, I would now argue that the current scheme is perfectly OK and can do > > everything you can do with the "strict" one, > > I forgot commenting this bit. This is not true, because I don't want a > low fd to be notified on critical level. The current interface just > can't do that.
Why can't you use poll() and demultiplex the events? Check if there is an event in the crit fd, and if there is, then just ignore all the rest.
> However, it *is* possible to make non-strict work on strict if we make > strict default _and_ make reads on memory.pressure_level return > available events. Just do this on app initialization: > > for each event in memory.pressure_level; do > /* register eventfd to be notified on "event" */ > done
This scheme registers "all" events. Here is more complicated case:
Old kernels, pressure_level reads:
low, med, crit
The app just wants to listen for med level.
New kernels, pressure_level reads:
low, FOO, med, BAR, crit
How would application decide which of FOO and BAR are ex-med levels?
Anton
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