Messages in this thread | | | Date | Tue, 3 Mar 2020 18:24:58 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH 1/2] trace: Export anonymous tracing |
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On Sun, 01 Mar 2020 22:22:25 +0000 Chris Wilson <chris@chris-wilson.co.uk> wrote:
> Quoting Steven Rostedt (2020-03-01 18:18:16) > > On Sun, 1 Mar 2020 15:52:47 +0000 > > Chris Wilson <chris@chris-wilson.co.uk> wrote: > > > > > To facilitate construction of per-client event ringbuffers, in > > > particular for a per-client debug and error report log, it would be > > > extremely useful to create an anonymous file that can be handed to > > > userspace so that it can see its and only its events. trace already > > > provides a means of encapsulating the trace ringbuffer into a struct > > > file that can be opened via the tracefs, and so with a couple of minor > > > tweaks can provide the same access via an anonymous inode. > > > > I'm curious to why we need it to be anonymous. Why not allow them to be > > visible from the tracing directory. This could allow for easier > > debugging. Note, the trace instances have ref counters thus they can't > > be removed if something has a reference to it. > > Do you really want a few thousand (or even tens) i915-client-%d? That > does not particularly seem like it adds ease-of-use, and would need to be > restricted to the client [or root]. The intent is for the client to have > a private channel for detailed debug/error reporting of its own calls > into the kernel.
Fair enough,
I would still want "trace_array_create()" to take a name. If it is NULL, it becomes anonymous, but if you want it to appear in the tracing directory, you can add a name to it.
Again, adding kernel doc comments to the global functions is still necessary.
-- Steve
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