Messages in this thread Patch in this message | | | Subject | Re: [PATCH v5 0/2] perf: riscv: Preliminary Perf Event Support on RISC-V | From | Atish Patra <> | Date | Tue, 24 Apr 2018 12:27:26 -0700 |
| |
On 4/24/18 11:07 AM, Atish Patra wrote: > On 4/19/18 4:28 PM, Alan Kao wrote: >> This implements the baseline PMU for RISC-V platforms. >> >> To ease future PMU portings, a guide is also written, containing >> perf concepts, arch porting practices and some hints. >> >> Changes in v5: >> - Fix patch errors from checkpatch.pl. >> >> Changes in v4: >> - Fix several compilation errors. Sorry for that. >> - Raise a warning in the write_counter body. >> >> Changes in v3: >> - Fix typos in the document. >> - Change the initialization routine from statically assigning PMU to >> device-tree-based methods, and set default to the PMU proposed in >> this patch. >> >> Changes in v2: >> - Fix the bug reported by Alex, which was caused by not sufficient >> initialization. Check https://lkml.org/lkml/2018/3/31/251 for the >> discussion. >> >> Alan Kao (2): >> perf: riscv: preliminary RISC-V support >> perf: riscv: Add Document for Future Porting Guide >> >> Documentation/riscv/pmu.txt | 249 ++++++++++++++ >> arch/riscv/Kconfig | 13 + >> arch/riscv/include/asm/perf_event.h | 79 ++++- >> arch/riscv/kernel/Makefile | 1 + >> arch/riscv/kernel/perf_event.c | 485 ++++++++++++++++++++++++++++ >> 5 files changed, 823 insertions(+), 4 deletions(-) >> create mode 100644 Documentation/riscv/pmu.txt >> create mode 100644 arch/riscv/kernel/perf_event.c >> > Most of the perf tests either pass or fail because of unsupported > event/trace point which is fine. > > However, I got an rcu-stall for the test "47: Event times". > # ./perf test -v 47 > 47: Event times : > --- start --- > test child forked, pid 2774 > attaching to spawned child, enable on exec > OK : ena 2243000, run 2243000 > attaching to current thread as enabled > OK : ena 19000, run 19000 > attaching to current thread as disabled > OK : ena 5000, run 5000 > attaching to CPU 0 as enabled > [ 1001.466578] INFO: rcu_sched self-detected stall on CPU > [ 1001.470947] 4-....: (29999 ticks this GP) idle=5fa/140000000000001/0 > softirq=19762/19762 fqs=14602 > [ 1001.480053] (t=30001 jiffies g=3471 c=3470 q=125) > [ 1001.484917] Task dump for CPU 4: > [ 1001.488129] perf R running task 0 2774 2773 > 0x00000008 > [ 1001.495161] Call Trace: > [ 1001.497606] [<000000006a3d4f87>] walk_stackframe+0x0/0xc0 > [ 1001.502980] [<000000004b4b0780>] show_stack+0x3c/0x46 > [ 1001.508024] [<0000000060c96ab8>] sched_show_task+0xd0/0x122 > [ 1001.513573] [<000000007d8bd54e>] dump_cpu_task+0x50/0x5a > [ 1001.518870] [<0000000053990e11>] rcu_dump_cpu_stacks+0x98/0xd2 > [ 1001.524685] [<00000000fe94c593>] rcu_check_callbacks+0x614/0x822 > [ 1001.530680] [<0000000057688dd3>] update_process_times+0x38/0x6a > [ 1001.536585] [<0000000063a96de0>] tick_periodic+0x58/0xd8 > [ 1001.541876] [<0000000013d712f1>] tick_handle_periodic+0x2e/0x7c > [ 1001.547780] [<000000009e2ef428>] riscv_timer_interrupt+0x34/0x3c > [ 1001.553774] [<00000000ff6b1f18>] riscv_intc_irq+0xbc/0xe0 > [ 1001.559153] [<00000000c8614c3b>] ret_from_exception+0x0/0xc > > It is quite possible that we don't support some dependency > infrastructure. I am looking into it. > > Regards, > Atish > > > > >
Got it working. The test tries to attach the event to CPU0 which doesn't exist in HighFive Unleashed. Changing it to cpu1 works.
diff --git a/tools/perf/tests/event-times.c b/tools/perf/tests/event-times.c index 1a2686f..eb11632f 100644 --- a/tools/perf/tests/event-times.c +++ b/tools/perf/tests/event-times.c @@ -113,9 +113,9 @@ static int attach__cpu_disabled(struct perf_evlist *evlist) struct cpu_map *cpus; int err;
- pr_debug("attaching to CPU 0 as enabled\n"); + pr_debug("attaching to CPU 1 as disabled\n");
- cpus = cpu_map__new("0"); + cpus = cpu_map__new("1"); if (cpus == NULL) { pr_debug("failed to call cpu_map__new\n"); return -1; @@ -142,9 +142,9 @@ static int attach__cpu_enabled(struct perf_evlist *evlist) struct cpu_map *cpus; int err;
- pr_debug("attaching to CPU 0 as enabled\n"); + pr_debug("attaching to CPU 1 as enabled\n");
- cpus = cpu_map__new("0"); + cpus = cpu_map__new("1"); if (cpus == NULL) { pr_debug("failed to call cpu_map__new\n"); return -1;
Palmer, Would it be better to officially document it somewhere that CPU0 doesn't exist in the HighFive Unleashed board ? I fear that there will be other standard tests/code path that may fail because of inherent assumption of cpu0 presence.
Regards, Atish
| |