Re: [PATCH][RFC]: mutex: adaptive spin

Linus Torvalds
2009-01-06T16:59:52Z

On Tue, 6 Jan 2009, Ingo Molnar wrote:
>
> So instead of the BUG_ON() we could emit a WARN_ONCE() perhaps, plus not
> do any spinning and just block - resulting in an uninterruptible task
> (that the user will probably notice) and a scary message in the syslog?
> [all in the slowpath]

Sure. You could put it in the adaptive function thing, with something like

if (WARN_ONCE(waiter == owner))
return 1;

which should fall back on the old behavior and do the one-time warning.

Linus