On 11/9/21 12:49 PM, Sai Prakash Ranjan wrote: > On 11/9/2021 11:10 PM, Steven Rostedt wrote: >> On Tue, 9 Nov 2021 23:00:11 +0530 >> Sai Prakash Ranjan <quic_saipraka@xxxxxxxxxxx> wrote: >> >>> Ah that's a very good idea, descriptor does contain the module, file name. >>> We can probably even pass the module name,file name as string from the >>> descriptor itself to event? >>> Perhaps we can do that for all trace events and not just this trace >>> event? Just like the trace event name displayed >>> with trace events, perhaps have file name,module name displayed when >>> dynamic debug is enabled? Filtering by >>> filename is pretty useful since most of these usecases in debugging will >>> be with respect to some driver or subsystems. >> If we add this for all events, it would require a lot of changes to all >> users of tracepoints, as it would require adding a new parameter to the >> callbacks. >> >> We could add a flag in the registering that states that the callback is OK >> for it, and it passes that data as well. >> >> Let me look into this for a bit. I may not have something this week, but >> we should look into this more before adding little hacks that do this one >> at a time like this patch. >> >> -- Steve > > Sure, thanks for the help and review. I can skip this patch adding support for dynamic event tracing > till we have something concrete as the previous patches doesn't depend on this. > > Thanks, > Sai Hi, Yeah there is a 'parallel' thread about adding the tracing ring buffer as a 'back end' to the dynamic debug stuff over here: https://lore.kernel.org/lkml/20211105192637.2370737-9-jim.cromie@xxxxxxxxx/ The attempt there is more generic but I realize now that it is adding the tracing to an 'instance' which is specific to dynamic debug which is being created via: trace_array_get_by_name(). I would prefer to just have it print to the 'main' trace buffer such that it's easier to read, although I guess they could still be consolidated via timestamps. Hmmm...I think there was a previous proposal to just add a single tracepoint (that takes a string) to the dynamic debug layer that could be called if a dynamic debug site is enabled for trace buffer output. Would that satisfy the ftrace level filtering requirements that you are looking for? Thanks, -Jason
