On Fri, 9 May 2025 14:53:38 -0700 Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > @@ -224,6 +224,10 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, > > struct perf_callchain_entry_ctx ctx; > > int rctx, start_entry_idx; > > > > + /* crosstask is not supported for user stacks */ > > + if (crosstask && user) > > + return NULL; > > I think get_perf_callchain() supports requesting both user and kernel > stack traces, and if it's crosstask, you can still get kernel (but not > user) stack, if I'm reading the code correctly. > > So by just returning NULL early you will change this behavior, no? Basically you are saying that one could ask for a kernel/user stack trace with crosstask enabled and still just get the kernel trace? If this is the case, then I think it may be best to remove patches 15-18 from this series and work on them in the "perf specific" series, as this doesn't have anything to do with the unwind infrastructure itself. Actually, patch 14 doesn't either, so I may move that one too (and keep the acks to it). Thanks, -- Steve > > > + > > entry = get_callchain_entry(&rctx); > > if (!entry) > > return NULL;
