[lsb-discuss] LSB conf call notes for 2008-04-30

[Jeff Licquia]

Joseph Kowalski wrote:
> If its a rumor, perhaps you could share it with me?

Sorry.  The notes can get a little terse...

The rumor was that Java 7 had eliminated all use of syscall from the 
Linux-specific code.

> I spent some time looking at what Mats posted (relevant to Java usage of
> syscall).  I pretty much agree with what he said (after all, most of this
> was from the comments in the sources).
> 
> However, I think the issues could be generalized to any, "interesting",
> multi-threaded application.  (gettid and fork on 64-bits)
> I have no clue as to why it appropriate to have a "gettid" manpage yet
> not have the wrapper.  All this results in is the awkward use of
> syscall(SYSgetti,...) rather than gettid(...).  Either its "private" 
> (hence,
> no manpage) or its public (should have a wrapper).  I don't see any
> reason for being half-way.

I think we're in agreement.  The kernel people at the Summit were 
shocked to learn of this, and perhaps there will be some improvements in 
the future.

But in the meantime, we have to work with the Linux we have.

> I'd agree that having to fumble around via /proc isn't the cleanest or
> most efficient way to access this information.  However, I'm not sure
> that a "generic interface" is the way to go.  You really don't want
> applications to depend upon all the interesting stuff /proc can tell
> you.  /proc is "a lot of rope".

The idea that's been talked about is not necessarily a "generic 
interface to /proc and /sys" so much as a "generic interface for 
learning interesting stuff about the system".

The difference is twofold.  First, it wouldn't leak the structure of 
/proc at all, so it could be theoretically implemented without reference 
to /proc at all.  Second, we could pick and choose what data is exposed.

> If you want, the original author of /proc works for Sun.  I suspect
> that he has already talked to the Linux maintainers of /proc, but if
> there are specific issues, I could ask him.

If he's interested in joining the conversation, his feedback would be 
valuable even if we didn't have specific questions.  (*I* don't right 
now, but I don't want to speak for everyone here.)