On Wed, 16 Oct 2013, Anton Vorontsov wrote: > > Vmpressure has two important levels: medium and critical. Medium is > > defined at 60% and critical is defined at 95%. > > > > We have a customer who needs a notification at a higher level than medium, > > which is slight to moderate reclaim activity, and before critical to start > > throttling incoming requests to save memory and avoid oom. > > > > This patch adds the missing link: a high level defined at 80%. > > > > In the future, it would probably be better to allow the user to specify an > > integer ratio for the notification rather than relying on arbitrarily > > specified levels. > > Does the customer need to differentiate the two levels (medium and high), > or the customer only interested in this (80%) specific level? >
Only high. > In the latter case, instead of adding a new level I would vote for adding > a [sysfs] knob for modifying medium level's threshold. > Hmm, doesn't seem like such a good idea. If one process depends on this being 60% and another depends on it being 80%, we're stuck. I think it's legitimate to have things like low, medium, high, and critical as rough approximations (and to keep backwards compatibility), but as mentioned in the changelog I want to extend the interface to allow integer writes to specify their own ratio. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
