cvs commit: src/sys/kern uipc_debug.c uipc_sockbuf.c uipc_socket.c uipc_syscalls.c src/sys/netinet sctputil.c src/sys/sys socketvar.h

[Alfred Perlstein]

* Robert Watson <rwatson at FreeBSD.org> [070503 10:08] wrote:
> 
> >
> >Now process B is in an uninterruptable wait until the remote side drains 
> >the pipe.
> >
> >The same problem might happen (even easier to reproduce) when there are 
> >multiple readers.
> >
> >Of course this all depends on me missing something.
> >
> >Can you explain?
> 
> You are entirely right -- I'm not sure how I missed the SB_NOINTR flag 
> semantics in sb_lock(), but apparently I did.  I'm talking to Attilio right 
> now about adding an interruptible version of the sleeping exclusive lock 
> acquire and will follow up on this shortly.  Thanks for pointing this out!

OK, please do your usual awesome benchmarking though so that this
potential fix doesn't wind up being a performance pessimizing stopgap.

I'm somewhat surprised that an attempt to move from sleep to cv based
rendevous wasn't attempted first.

-- 
- Alfred Perlstein