On Fri, 11 Apr 2025 14:00:40 +0100 Mark Brown <broo...@kernel.org> wrote:
> On Thu, Apr 10, 2025 at 01:17:45PM -0400, Steven Rostedt wrote: > > Mark Brown <broo...@kernel.org> wrote: > > > > We've been seeing the PID filters selftest failing for a while on > > > several arm64 systems, a bisect I managed to run without running into > > > any confounding issues pointed to this patch which is in mainline as > > > ff5c9c576e75. It's in the ftrace code, but I'm not immediately seeing > > > the relevance. Output from a failing run: > > > Hmm, I wonder if there's junk being added into the trace. > > > Can you add this patch, and show me the output when it fails again? > Can you show the information before this output, to see what it is actually testing? > # # + cat trace > # # # tracer: function_graph > # # # > # # # CPU TASK/PID DURATION FUNCTION CALLS > # # # | | | | | | | | | > # # 0) ftracet-5190 | ! 537.633 us | kernel_clone(); /* ret=0x1470 */ > # # > # # 0) ftracet-5190 | ! 508.253 us | kernel_clone(); /* ret=0x1471 */ > # # > # # 0) ftracet-5190 | ! 215.716 us | kernel_clone(); /* ret=0x1476 */ > # # > # # 0) ftracet-5190 | ! 493.890 us | kernel_clone(); /* ret=0x147b */ > # # > # # + fail PID filtering not working? > > ... > > # # + cat trace > # # # tracer: function_graph > # # # > # # # CPU TASK/PID DURATION FUNCTION CALLS > # # # | | | | | | | | | > # # 0) ftracet-12279 | ! 598.118 us | kernel_clone(); /* ret=0x301f */ > # # > # # 0) ftracet-12279 | ! 492.539 us | kernel_clone(); /* ret=0x3020 */ > # # > # # 0) ftracet-12279 | ! 231.104 us | kernel_clone(); /* ret=0x3025 */ > # # > # # 0) ftracet-12279 | ! 555.566 us | kernel_clone(); /* ret=0x302a */ > # # > # # + fail PID filtering not working? Also, is it possible to just enable function_graph tarcing and see if it adds these blank lines between events? -- Steve
