Fine-grained locking for POSIX local sockets ( UNIX domain sockets )

David Xu davidxu at
Thu May 11 23:28:43 UTC 2006

On Friday 12 May 2006 01:58, Robert Watson wrote:
> On Thu, 11 May 2006, Scott Long wrote:
> >> So I guess the real question is: do we want to merge the UNIX domain
> >> socket locking work?  The MySQL gains sound good, the performance drop
> >> under very high load seems problematic, and there are more general
> >> questions about performance with other workloads.
> >>
> >> Maintaining this patch for a month or so is no problem, but as the tree
> >> changes it will get harder.
> >
> > The only thing I'm afraid of is that it'll get pushed onto the
> > back-burner once it's in CVS, and we'll have a mad scramble to fix it
> > when it's time for 7.0.  That's not a show-stopper for it going in, as
> > there are also numerous benefits.  It's just something that needs to be
> > tracked and worked on.
> I should be able to support/improve UNIX domain sockets moving forward
> without a problem -- the maintenance issue is maintaining it in P4
> indefinitely, not in the tree indefinitely, as the patch basically touches
> every line in the file, so any change in the vendor branch (FreeBSD CVS)
> will put the entire file into conflict.  To be specific: I'll track and own
> this, but want to avoid having it in P4 indefinitely, because it will get
> stale :-).
> Robert N M Watson

Your patch makes other bottlenecks more visible than before, for example,
file descriptor locking, but it is not a problem of your patch, so I think
it is fine to commit it.

David Xu

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