On 03/03/11 10:19, Frederic Weisbecker wrote: > On Thu, Mar 03, 2011 at 07:20:10AM -0700, David Ahern wrote: >> On 03/02/2011 08:05 PM, Frederic Weisbecker wrote: >>> Hmm, that's a wrong way of walking through callchains. In fact it's not >>> a classical list. node->next can be a ghost entry from a previous callchain >>> that we kept cached in order to optimize allocations. >>> >>> You need the accessors callchain_cursor_current() and callchain_cursor_advance(). >> >> Ok. I'll look at perf-report's callchain_append again. > > Yeah callchain_append() is too much a generic name for something actually > rather specific. In fact callchain_append() adds a callchain, already > resolved, to a histogram in order to produce that statistical tree in the end > that you can have with perf report. > > But you don't need those statistical tree of callchains, it's only used > by perf report for now. Instead you rather need to treat every callchains > individually and print each of them. > > So you don't even need callchain_append(). All you need in the end is Right, just using that as an example of how callchains are handled. > to use perf_session__resolve_callchain() that resolves the raw struct ip_callchain > (only made of raw ips) into a cursor (list of ips resolved into symbols and so) and > walk through the cursor with the two accessors. > > Ah I forgot, you first need to use callchain_cursor_commit() in order to initialize > the position in the cursor. > > So: > > 1) Resolve with perf_session__resolve_callchain() > 2) commit with callchain_cursor_commit() > 3) iterate with callchain_cursor_current(), callchain_cursor_advance() yes, I figured out the missing commit, and I changed the loop to: while (1) { node = callchain_cursor_current(cursor); if (!node) break; ... (print chain) callchain_cursor_advance(cursor); } Thanks for the comments. What about the python and perl engines? Right now they are tracepoint specific. I do not have a sufficient background in either to expand to other sample types. David > > Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html