On Tuesday, September 17, 2013 6:21:10 am Gleb Smirnoff wrote: > Hi! > > When system is writing a kernel core dump, it issues watchdog > pat wdog_kern_pat(WD_LASTVAL). If ipmi is in action, it registers > ipmi_wd_event() as event for watchdog. Thus ipmi_wd_event() is > called in dumping context. > > The problem is that ipmi_wd_event() calls into ipmi_set_watchdog(), > that calls into ipmi_alloc_request(), which uses M_WAITOK and > thus sleeps. This is a smaller problem, since can be converted to > M_NOWAIT. But ipmi_set_watchdog() then calls into > ipmi_submit_driver_request(), which calls msleep() any time. > > The attached patch allows me to successfully write cores in > presence of IPMI.
Of course, the watchdog might go off during your dump. :) The real fix is more complicated, which is that we should not use a worker thread for at least SMIC and KCS. -- John Baldwin _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
