On 25/01/2024 2:12 pm, Jan Beulich wrote: > "watchdog_timeout=0" is documented to disable the watchdog. Make sure > this also is true when there's a subsequent "watchdog" command line > option (and no further "watchdog_timeout=" one).
We also document that latest takes precedence, at which point "watchdog" would re-activate. > > While there also switch watchdog_setup() to returning void, bringing it > in line with the !CONFIG_WATCHDOG case. Further amend command line > documentation to also mention the implicit effect of specifying a non- > zero timeout. > > Signed-off-by: Jan Beulich <jbeul...@suse.com> > --- > Alternatively "watchdog" following "watchdog_timeout=0" could be taken > to mean to use the default timeout again. I realise that watchdog_timeout is my fault, but in fairness it was an early change of mine in Xen and didn't exactly get the kind of review it would get these days. It also wasn't used by XenServer in the end - we just stayed at a default 5s. I'm very tempted to suggest deleting watchdog_timeout, and extending watchdog= to have `force | <bool> | <int>s` so you could specify e.g. `watchdog=10s`. The watchdog is off by default so I don't expect this will impact people. It is also more convenient for the end user, and means that we don't have have the current split approach of two separate options fighting for control over each other. It also means we we can in principle support non-integer-second units of time in a theoretical future when the NMI handler can count time properly. > Really I think the comment in watchdog_setup() is wrong, and the > function would hence better go away. That comment dates from 2006. I highly suspect it's not true any more, and it certainly is odd to be running over all CPUs like that. ~Andrew
