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
--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
