Messages in this thread | | | From | Kumar Gala <> | Subject | Re: handling watchdog in SMP | Date | Wed, 23 Apr 2008 08:22:24 -0500 |
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On Oct 25, 2007, at 2:37 PM, Wim Van Sebroeck wrote: > Hi Kumar, > >> I was hoping to get some ideas on how to handle the watchdog timers >> we have on some embedded PPC (booke_wdt.c) cores when we are in a SMP >> system. >> >> The problem is since the watchdog is part of the processor core >> depending on which processor a given system call is executed at we >> might get different behavior. It seems like we would want to mirror >> the actions to both cores (via smp_call_function). >> >> Looking at the file ops we currently support in booke_wdt.c it seems >> like we could mirror the actions for booke_wdt_write()/booke_wdt_ping >> () to both cores and ensure when we set something like >> WDIOC_SETTIMEOUT we set the registers in both processors. >> >> I was wondering if anyone had any other ideas or if this model seems >> to work. > > I see 2 ways to go: > 1) short term: make sure that your actions are duplicated to both > cores > (like you said). At least then you are protected if your complete > system > crashes. > 2) I'm working on the uniform/generic watchdog device driver. Phase > 1 is > the "new" api and the /dev/watchdog handling. Phase 2 is a sysfs > interface. > Phase 3 is to allow multiple devices (and there I'm still thinking > about > how the /dev/watchdog interface should work). > But the general idea is to allow at least the control of each watchdog > device by the sysfs interface.
I haven't been following watchdog subsystem development and was wondering if any progress has been made on #2?
- k
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