On Tue, Jun 04, 2019 at 11:17:48PM -0700, Christoph Hellwig wrote: > > The following patches add the bare minimum tracepoints required to perform > > EAS > > testing in Lisa[1]. > > What is EAS? Whhy is "Lisa" not part of the patch submission? > submission. > > > It is done in this way because adding new TRACE_EVENTS() is no longer > > accepted > > AFAIU. > > Huh? We keep adding trace events all the time. And they actually > are useful because they are testable.
They also form an implicit API/ABI with userspace, and I've been bitten by that crap before. No more tracepoints. IIRC viro is also not having tracepoints in the vfs. > This series on the other hand adds exports not used in tree, which is > a big no-go. I much prefer a few unused exports that expose data in a controlled fashion than commit to an implicit ABI through tracepoints. By keeping it all in kernel, we're punting to the no-in-kernel-ABI rule. Basically nobody gives a crap if we break (out-of-tree) modules, but the moment we break something userspace we're fscked.
