On 02/22/2017 09:06 PM, Benjamin Herrenschmidt wrote: > On Wed, 2017-02-22 at 17:25 +1100, Michael Ellerman wrote: >> >> Thanks for the detailed explanation. >> >> The patches look fine, so I don't see any reason why we wouldn't merge >> this. I might make the config option depend on EXPERT, but that's just >> cosmetic. >> >> >> You're right about the difference in stack overhead between 32 & 64-bit. >> But I guess on the other hand we've been using 16K stacks on 64-bit for >> over 15 years, and although we have had some reports of stack overflow >> they're not a common problem. > > Right and in fact I wonder if we could generally help this for cases > like this one (lots of stacked devices) by having the generic driver > core break those chains by deferring new device registration to a work > queue or kthread. > > That would help in a lot of cases. We do get some stupid deep chains > in cases of many bus encapsulation. > > Cheers, > Ben. > > Agreed. In fact you suggested it back in 2008 somewhere in the thread I linked to in my cover letter for the series. That's obviously going to take a long time to happen, so for now I hope this series will allow some respite for users affected.
Thanks for your input.
