Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 22 Dec 2009 17:13:53 +0100 | From | Jiri Olsa <> | Subject | Re: [RFC PATCH] dynamic debug - adding ring buffer storage support |
| |
On Tue, Dec 22, 2009 at 10:39:56AM -0500, Jason Baron wrote: > On Tue, Dec 22, 2009 at 12:32:06PM +0100, Jiri Olsa wrote: > > Hi, > > > > as I use dynamic debug sometimes, I thought it could be useful having > > the possibility to store the output somewhere else than dmesg. > > > > The attached patch implements support for storing dynamic debug > > messages to the ring buffer. > > > > The dynamic debug allows simple addition of new flags, > > so I added 'r' flag for ring buffer storage. > > > > I used the ring buffer implementation from trace framework. > > > > hopefuly this could be any use for others as well... > > plz let me know what you think, > > > > jirka > > > > hi, > > I like the idea of using the ring buffer for output. However, I'm not > sure why we need a separate one for this. I like adding the 'r' for ring > buffer storage, by why not just make this path call 'trace_printk()', and > store the string in the existing kernel tracing ring buffer? That way it > can interleave with other trace data as well.
that way you need to enable tracing as well... but thats ok I guess :)
I was investigating trace events for this, but did not find a way to put variable length argument inside... and I overlooked the trace_printk, I'll look on it and see how it fits, thanks
also having separate ring buffer makes the 'trace'/'trace_pipe' code really simple (suprissingly) compared to ftrace, and I thought on this place it could last for some time.. ;)
jirka
> > thanks, > > -Jason
| ![\](/images/icornerr.gif) |