Messages in this thread |  | | Date | Sat, 17 Aug 2002 01:59:58 +1000 (EST) | From | James Morris <> | Subject | Re: [PATCH][RFC] sigurg/sigio cleanup for 2.5.31 |
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On Fri, 16 Aug 2002, Jeff Dike wrote:
> This introduces a window within which SIGIO will be dropped.
Yes.
> As it stands, this will break UML. Lost SIGIOs will cause UML hangs.
Ugh.
> > If you're determined to avoid spinlocks, why not do something like this: > > + if (!pid) > + return; > + while(fown->pid == PID_INVALID) ; > > maybe with a cpu_relax() in the loop. > > But that starts looking a lot like a spinlock.
Although it should be better at not hurting the common case (no contention), as f_setown() calls should be rare occurences in comparison to normal SIGIO generation.
> Also, shouldn't there be a capable(CAP_KILL) in here rather than a check > for uid == 0?
CAP_KILL was only previously used for sockets when calling F_SETOWN and FIOSETOWN, and was not checked during delivery. The cleanup just brings sockets into line with ttys, futexes and directories. It may be a good idea, but probably out of scope of this cleanup.
- James -- James Morris <jmorris@intercode.com.au>
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