On Thu, 13 Jan 2022 13:27:34 +0100 Jiri Olsa <jolsa@xxxxxxxxxx> wrote: > On Wed, Jan 12, 2022 at 05:01:15PM +0100, Jiri Olsa wrote: > > On Wed, Jan 12, 2022 at 11:02:46PM +0900, Masami Hiramatsu wrote: > > > Hi Jiri and Alexei, > > > > > > Here is the 2nd version of fprobe. This version uses the > > > ftrace_set_filter_ips() for reducing the registering overhead. > > > Note that this also drops per-probe point private data, which > > > is not used anyway. > > > > > > This introduces the fprobe, the function entry/exit probe with > > > multiple probe point support. This also introduces the rethook > > > for hooking function return as same as kretprobe does. This > > > > nice, I was going through the multi-user-graph support > > and was wondering that this might be a better way > > > > > abstraction will help us to generalize the fgraph tracer, > > > because we can just switch it from rethook in fprobe, depending > > > on the kernel configuration. > > > > > > The patch [1/8] and [7/8] are from your series[1]. Other libbpf > > > patches will not be affected by this change. > > > > I'll try the bpf selftests on top of this > > I'm getting crash and stall when running bpf selftests, > the fprobe sample module works fine, I'll check on that OK, I got a kernel stall. I missed to enable CONFIG_FPROBE. I think vmtest.sh should support menuconfig option. #6 bind_perm:OK #7 bloom_filter_map:OK [ 107.282403] clocksource: timekeeping watchdog on CPU0: Marking clocksource 'tsc' as unstable because the skew is too large: [ 107.283240] clocksource: 'hpet' wd_nsec: 496216090 wd_now: 7ddc7120 wd_last: 7ae746b7 mask: ffffffff [ 107.284045] clocksource: 'tsc' cs_nsec: 495996979 cs_now: 31fdb69b39 cs_last: 31c2d29219 mask: ffffffffffffffff [ 107.284926] clocksource: 'tsc' is current clocksource. [ 107.285487] tsc: Marking TSC unstable due to clocksource watchdog [ 107.285973] TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'. [ 107.286616] sched_clock: Marking unstable (107240582544, 45390230)<-(107291410145, -5437339) [ 107.290408] clocksource: Not enough CPUs to check clocksource 'tsc'. [ 107.290879] clocksource: Switched to clocksource hpet [ 604.210415] INFO: rcu_tasks detected stalls on tasks: [ 604.210830] (____ptrval____): .. nvcsw: 86/86 holdout: 1 idle_cpu: -1/0 [ 604.211314] task:test_progs state:R running task stack: 0 pid: 87 ppid: 85 flags:0x00004000 [ 604.212058] Call Trace: [ 604.212246] <TASK> [ 604.212452] __schedule+0x362/0xbb0 [ 604.212723] ? preempt_schedule_notrace_thunk+0x16/0x18 [ 604.213107] preempt_schedule_notrace+0x48/0x80 [ 604.217403] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 604.217790] ? ftrace_regs_call+0xd/0x52 [ 604.218087] ? bpf_test_finish.isra.0+0x190/0x190 [ 604.218461] ? bpf_fentry_test1+0x5/0x10 [ 604.218750] ? trace_clock_x86_tsc+0x10/0x10 [ 604.219064] ? __sys_bpf+0x8b1/0x2970 [ 604.219337] ? lock_is_held_type+0xd7/0x130 [ 604.219680] ? __x64_sys_bpf+0x1c/0x20 [ 604.219957] ? do_syscall_64+0x35/0x80 [ 604.220237] ? entry_SYSCALL_64_after_hwframe+0x44/0xae [ 604.220653] </TASK> Jiri, is that what you had seen? Thank you, -- Masami Hiramatsu <mhiramat@xxxxxxxxxx>
