Re: [PACTH v1] trace: Add trace events for open(), exec() and uselib()

[Robert Foss]

On 2016-08-01 02:10 PM, Al Viro wrote:
> On Mon, Aug 01, 2016 at 01:25:40PM -0400, robert.foss@xxxxxxxxxxxxx wrote:
> > From: Scott James Remnant <scott@xxxxxxxxxx>
> >
> > This patch uses TRACE_EVENT to add tracepoints for the open(),
> > exec() and uselib() syscalls so that ureadahead can cheaply trace
> > the boot sequence to determine what to read to speed up the next.
>
> NAK.  No Tracepoints In VFS.  Not going to happen - any tracepoint can all too
> easily become a cast-in-stone userland ABI.

Hey Al,

I'm slightly unfamiliar with this territory, so please forgive my lack 
of knowledge of this topic.

What is the negative side of having tracepoint be a permanent fixture in 
the VFS ABI?
And how is VFS different from other subsystems in that regard?


Rob.