On 31/05/15 20:00, Thomas Meyer wrote: > Am Sonntag, den 31.05.2015, 13:15 +0200 schrieb Richard Weinberger: >> Am 20.05.2015 um 07:26 schrieb Thomas Meyer: >>> Am 20.05.2015 12:12 vorm. schrieb Richard Weinberger < >>> richard.weinber...@gmail.com>: >>>> On Sun, May 17, 2015 at 11:25 AM, Thomas Meyer <tho...@m3y3r.de> >>>> wrote: >>>>> Switch the UML clocksource from interval timers to posix >>>>> interval timers >>>>> and move to a monotonic timer. >>>>> >>>>> This fixes suspend&resume related timer issues and improves >>>>> network >>>>> performance as TCP state machines are now fed with the correct >>>>> time; >>>>> also correct QoS and traffic shaping. >>>>> >>>>> Signed-off-by: Thomas Meyer <tho...@m3y3r.de> >>>> What tree is this patch against? >>>> It does not clearly apply to Linus' tree. >>>> >>> Hi, >>> >>> I did tested the patch against 4.1-rc3-something; will update the >>> patch against the latest commit! > Hi, > >> Ping. >> Would be nice to have this patch for the 4.2 merge window. > I can provide you the current version of the patch, but I'm not sure if > it's ready for inclusion yet.
Agree. > For example: > - With this patch I see new zombie processes of UML userspace > processes. I'm not sure what's going on here. +1 > - Anton reported some hang he sees with this patch I did not have a chance to work on it last week, will try to find some time this week. > - A person from cicso is worried about the potential idle CPU usage > after the patch, because of the many timers started, i.e. a host with > hundreds of UMLs. This is less then the old CPU usage - checking time and rearming nanosleeps and itimers is expensive. > > Also meanwhile I think is not the correct thing to start a new timer > for each UML userspace process, because the timer will also trigger the > userspace process, even the corresponding process isn't scheduled by > the kernel currently. I think the previous behaviour with the itimer > was okay, because the virtual timer only did execute when the process > was executing which is the correct thing to do for the currently active > task in the UML kernel. > I see two solutions for above problem: cascade the kernel timer into > the current active task; there is actually no need to start a timer in > each userspace process. > Start/stop each timer when a userspace process becomes active resp. > becomes inactive again. > I hope above logic makes some sense at all! What do you think about > this? Cascading the kernel timer looks like the correct solution. A. > > with kind regards > thomas > > > > ------------------------------------------------------------------------------ > _______________________________________________ > User-mode-linux-devel mailing list > User-mode-linux-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel > ------------------------------------------------------------------------------ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
