* Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> [100513 07:11]: > On Wed, 12 May 2010, Paul Walmsley wrote: > > > Hello, > > > > Some general comments on the suspend blockers/wakelock/opportunistic > > suspend v6 patch series, posted here: > > > > https://lists.linux-foundation.org/pipermail/linux-pm/2010-April/025146.html > > > > The comments below are somewhat telegraphic in the interests of > > readability - more specific comments to follow in later E-mails. I am > > indebted to those of us who discussed these issues at LPC last year and > > ELC this year for several stimulating discussions. > > > > There are several general problems with the design of opportunistic > > suspend and suspend-blocks. > > > > 1. The opportunistic suspend code bypasses existing Linux kernel code, > > such as timers and the scheduler, that indicates when code > > needs to run, and when the system is idle. > > Whoa! That's not my understanding at all. > > As I see it, opportunistic suspend doesn't bypass any code that isn't > already bypassed by the existing suspend code. Users can do > > echo mem >/sys/power/state > > whenever they want, without regard to kernel timers and the scheduler > (other than the fact that the user's thread must be running in order to > carry out the write, of course). The difference between echo mem > /sys/power/state and suspend blocks is that with suspend blocks the system keeps running. And that's why it should be handled by runtime power management instead. The suspend blocks seems like a hack to spam filter good and bad apps from timer usage point of view. Applications are categorized as good or bad depending if they grab a susped blocker or not. I believe categorizing the apps should be instead done with some timer flags or cgroups instead. Cheers, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
