> -----Original Message----- > From: Arjan van de Ven [mailto:[email protected]] > Sent: Wednesday, December 22, 2010 8:17 PM > To: Mathew, JohnX > Cc: Tardy, Pierre; al; [email protected] > Subject: Re: [Meego-kernel] Doubt about a timer stat > > On 12/22/2010 9:47 AM, Mathew, JohnX wrote: > >> -----Original Message----- > >> From: Arjan van de Ven [mailto:[email protected]] > >> Sent: Wednesday, December 22, 2010 5:48 PM > >> To: Tardy, Pierre > >> Cc: al; Mathew, JohnX; [email protected] > >> Subject: Re: [Meego-kernel] Doubt about a timer stat > >> On 12/22/2010 7:52 AM, Tardy, Pierre wrote: > >>>> On 12/21/2010 11:10 PM, al wrote: > >>>>> Hi, > >>>>> > >>>>> I keep seeing the following timer stat - > >>>>> 1, 1 init hrtimer_start_range_ns (hrtimer_wakeup) > >>>>> > >>>>> Can anyone please explain what init process cases this ? > >>>> which meego version is this on? > >>> On an old internal build from Oct, 14th, we are also seeing this > timer. (15 sec timer from init process) > >>> John was supposed to look at this this week. > >>> John, do you have any news on this ? > >>> init will check every 15 seconds or so if there's zombies to reap. > >>> we could make it 30 if it shows up as a power issue. > > After using the ftrace - func_stack_trace I found that the > fs/select.c - "select" system call is calling > schedule_hrtimeout_range_clock each time the init process wakes up the > system. > > So my assumption is that a userland application or the init process > itself is using the "select" system call to wait on a file descriptor. > > Pierre/Arjan have you seen this behavior before? > > I am having trouble finding out which is the exact userland > application it is.... > > > > it'll be init I suspect. > > > but.... why not run powertop 1.99 .. it'll tell you in quite a bit of > detail who's waking the CPU up ;-)
The init code which is causing the wakeup has been identified. It's not related to reaping of zombies. Instead it is because of a code checking the initctl fifo at 15 sec intervals. The original value of this check is 5 secs (sysvinit v 2.86). This was increased to 15 secs for Meego by a patch provided by Auke Kok. I don't think it would be a good idea to increase the interval any further as this check is responsible for handling init commands like PowerFail and Run level. Any other solution is welcome. --------------------------------------------------------------------- Intel Corporation SAS (French simplified joint stock company) Registered headquarters: "Les Montalets"- 2, rue de Paris, 92196 Meudon Cedex, France Registration Number: 302 456 199 R.C.S. NANTERRE Capital: 4,572,000 Euros This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. _______________________________________________ MeeGo-kernel mailing list [email protected] http://lists.meego.com/listinfo/meego-kernel
