On 2/5/2026 7:54 PM, Steven Rostedt wrote: > On Thu, 5 Feb 2026 10:26:10 -0800 > Namhyung Kim <[email protected]> wrote: > >>> Namhyung Kim's related perf tools deferred callchain support can be used >>> for testing ("perf record --call-graph fp,defer" and "perf report/script"). >>> >> >> Is it possible for users to choose the unwinder - frame pointer or >> SFrame at runtime? I feel like the option should be >> "--call-graph sframe,defer" or just "--call-graph sframe" if it always >> uses deferred unwinding. > > Currently no, and I'm not sure we want that do we? The idea is to use the > best option that is available. Why use frame pointers if sframe is > available and it's being called with defer? > > If there's no defer, then sframes are not available, so it defaults to the > best option available (which will likely be frame pointers).
Maybe it would make sense not to "overload" the perf record option "--call-graph fp,defer" and use it for all deferred unwinding methods. What about "--call-graph defer", "--call-graph any,defer", or "--call-graph *,defer"? Regards, Jens -- Jens Remus Linux on Z Development (D3303) [email protected] / [email protected] IBM Deutschland Research & Development GmbH; Vorsitzender des Aufsichtsrats: Wolfgang Wendt; Geschäftsführung: David Faller; Sitz der Gesellschaft: Ehningen; Registergericht: Amtsgericht Stuttgart, HRB 243294 IBM Data Privacy Statement: https://www.ibm.com/privacy/
