Hi, On Wed, Apr 19, 2023 at 09:32:10AM +0200, Eric Auger wrote: > Hi, > > On 4/12/23 10:47, Mark Rutland wrote: > > On Tue, Apr 04, 2023 at 02:47:47PM +0200, Andrew Jones wrote: > >> On Tue, Apr 04, 2023 at 08:23:15AM +0200, Eric Auger wrote: > >>> Hi, > >>> > >>> On 3/15/23 12:07, Eric Auger wrote: > >>>> On some HW (ThunderXv2), some random failures of > >>>> pmu-chain-promotion test can be observed. > >>>> > >>>> pmu-chain-promotion is composed of several subtests > >>>> which run 2 mem_access loops. The initial value of > >>>> the counter is set so that no overflow is expected on > >>>> the first loop run and overflow is expected on the second. > >>>> However it is observed that sometimes we get an overflow > >>>> on the first run. It looks related to some variability of > >>>> the mem_acess count. This variability is observed on all > >>>> HW I have access to, with different span though. On > >>>> ThunderX2 HW it looks the margin that is currently taken > >>>> is too small and we regularly hit failure. > >>>> > >>>> although the first goal of this series is to increase > >>>> the count/margin used in those tests, it also attempts > >>>> to improve the pmu-chain-promotion logs, add some barriers > >>>> in the mem-access loop, clarify the chain counter > >>>> enable/disable sequence. > >>>> > >>>> A new 'pmu-memaccess-reliability' is also introduced to > >>>> detect issues with MEM_ACCESS event variability and make > >>>> the debug easier. > > As a minor nit, 'pmu-mem-access-reliability' would be more consistent with > > 'pmu-mem-access'. The lack of a dash in 'memaccess' tripped me up while I was > > trying to run those two tests. > > I can easily respin with that renaming. thanks for the feedback. Waiting > a little bit more if somebody has any other comment. Started reviewing the series last week, something came up and I had to stop after the first patch (very nice improvement, by the way). I will finish the review by the end of this week. Thanks, Alex > > Eric > > > >>>> Obviously one can wonder if this variability is something normal > >>>> and does not hide any other bug. I hope this series will raise > >>>> additional discussions about this. > >>>> > >>>> https://github.com/eauger/kut/tree/pmu-chain-promotion-fixes-v1 > >>> Gentle ping. > >> I'd be happy to take this, but I was hoping to see some r-b's and/or t-b's > >> from some of the others. > > I gave this a spin on my ThunderX2, and it seems to fix the intermittent > > failures I was seeing. > > > > FWIW: > > > > Tested-by: Mark Rutland <mark.rutland@xxxxxxx> > > > > Before (on commit 4ba7058c61e8922f9c8397cfa1095fac325f809b): > > > > Test results below. > > > > | [mark@gravadlaks:~/src/kvm-unit-tests]% TESTNAME=pmu-chain-promotion TIMEOUT=90s ACCEL= useapp qemu ./arm/run arm/pmu.flat -smp 1 -append 'pmu-chain-promotion' > > | timeout -k 1s --foreground 90s /home/mark/.opt/apps/qemu/bin/qemu-system-aarch64 -nodefaults -machine virt,gic-version=host -accel kvm -cpu host -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -device pci-testdev -display none -serial stdio -kernel arm/pmu.flat -smp 1 -append pmu-chain-promotion # -initrd /tmp/tmp.nl1i6S0EIY > > | INFO: PMU version: 0x4 > > | INFO: PMU implementer/ID code: 0(" ")/0 > > | INFO: Implements 6 event counters > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: chain counter not counting if even counter is disabled > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: odd counter did not increment on overflow if disabled > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: MEM_ACCESS counter #0 has value 0x7 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: CHAIN counter #1 has value 0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: overflow counter 0x1 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: MEM_ACCESS counter #0 has value 0x4 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: MEM_ACCESS counter #0 has value 0x1b > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: should have triggered an overflow on #0 > > | FAIL: pmu: pmu-chain-promotion: 32-bit overflows: CHAIN counter #1 shouldn't have incremented > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: counter #0 = 0xffffffdc, counter #1 = 0x0 overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: MEM_ACCESS counter #0 has value 0x4 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: MEM_ACCESS counter #0 has value 0x1b > > | FAIL: pmu: pmu-chain-promotion: 32-bit overflows: CHAIN counter enabled: CHAIN counter was incremented and overflow > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: CHAIN counter #1 = 0x0, overflow=0x1 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: MEM_ACCESS counter #0 has value 0x4 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: MEM_ACCESS counter #0 has value 0x1b > > | FAIL: pmu: pmu-chain-promotion: 32-bit overflows: 32b->64b: CHAIN counter incremented and overflow > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: CHAIN counter #1 = 0x0, overflow=0x1 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: counter #0=0xfffffff3, counter #1=0x0 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: overflow is expected on counter 0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: counter #0=0xa, counter #1=0xf9 overflow=0x1 > > | SUMMARY: 7 tests, 3 unexpected failures > > > > After: > > > > | [mark@gravadlaks:~/src/kvm-unit-tests]% TESTNAME=pmu-chain-promotion TIMEOUT=90s ACCEL=kvm useapp qemu ./arm/run arm/pmu.flat -smp 1 -append 'pmu-chain-promotion' > > | timeout -k 1s --foreground 90s /home/mark/.opt/apps/qemu/bin/qemu-system-aarch64 -nodefaults -machine virt,gic-version=host -accel kvm -cpu host -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -device pci-testdev -display none -serial stdio -kernel arm/pmu.flat -smp 1 -append pmu-chain-promotion # -initrd /tmp/tmp.pahLyg1F3s > > | INFO: PMU version: 0x4 > > | INFO: PMU implementer/ID code: 0(" ")/0 > > | INFO: Implements 6 event counters > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest1: post #1=0x0 #0=0x0 overflow=0x0 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: subtest1: chain counter not counting if even counter is disabled > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest2: post #1=0x0 #0=0xf3 overflow=0x1 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: subtest2: odd counter did not increment on overflow if disabled > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest3: init #1=0x0 #0=0xfffffea1 overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest3: After 1st loop #1=0x0 #0=0xffffffa0 overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest3: After 2d loop #1=0x0 #0=0xc0 overflow=0x1 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: subtest3: should have triggered an overflow on #0 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: subtest3: CHAIN counter #1 shouldn't have incremented > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest4: init #1=0x0 #0=0xfffffea1 overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest4: After 1st loop #1=0x0 #0=0xffffffb7 overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest4: After 2d loop #1=0x1 #0=0xbc overflow=0x1 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: subtest4: CHAIN counter enabled: CHAIN counter was incremented and overflow > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest5: init #1=0x0 #0=0xfffffea1 overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest5: After 1st loop #1=0x22c #0=0xffffff9f overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest5: After 2d loop #1=0x1 #0=0x9d overflow=0x1 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: subtest5: 32b->64b: CHAIN counter incremented and overflow > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest6: init #1=0x0 #0=0xfffffea1 overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest6: After 1st loop #1=0x0 #0=0xffffff9f overflow=0x0 > > | INFO: pmu: pmu-chain-promotion: 32-bit overflows: subtest6: After 2d loop #1=0x1f9 #0=0x9c overflow=0x1 > > | PASS: pmu: pmu-chain-promotion: 32-bit overflows: subtest6: overflow is expected on counter 0 > > | SUMMARY: 7 tests > > > > As a bonus, the mem-access and memaccess-reliability results: > > > > | [mark@gravadlaks:~/src/kvm-unit-tests]% TESTNAME=pmu-chain-promotion TIMEOUT=90s ACCEL=kvm useapp qemu ./arm/run arm/pmu.flat -smp 1 -append 'pmu-mem-access' > > | timeout -k 1s --foreground 90s /home/mark/.opt/apps/qemu/bin/qemu-system-aarch64 -nodefaults -machine virt,gic-version=host -accel kvm -cpu host -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -device pci-testdev -display none -serial stdio -kernel arm/pmu.flat -smp 1 -append pmu-mem-access # -initrd /tmp/tmp.84AeEp8Tiw > > | INFO: PMU version: 0x4 > > | INFO: PMU implementer/ID code: 0(" ")/0 > > | INFO: Implements 6 event counters > > | INFO: pmu: pmu-mem-access: 32-bit overflows: counter #0 is 0x15 (MEM_ACCESS) > > | INFO: pmu: pmu-mem-access: 32-bit overflows: counter #1 is 0x15 (MEM_ACCESS) > > | PASS: pmu: pmu-mem-access: 32-bit overflows: Ran 20 mem accesses > > | PASS: pmu: pmu-mem-access: 32-bit overflows: Ran 20 mem accesses with expected overflows on both counters > > | INFO: pmu: pmu-mem-access: 32-bit overflows: cnt#0=0x8 cnt#1=0x8 overflow=0x3 > > | SKIP: pmu: pmu-mem-access: 64-bit overflows: Skip test as 64 overflows need FEAT_PMUv3p5 > > | SUMMARY: 3 tests, 1 skipped > > | [mark@gravadlaks:~/src/kvm-unit-tests]% TESTNAME=pmu-chain-promotion TIMEOUT=90s ACCEL=kvm useapp qemu ./arm/run arm/pmu.flat -smp 1 -append 'pmu-memaccess-reliability' > > | timeout -k 1s --foreground 90s /home/mark/.opt/apps/qemu/bin/qemu-system-aarch64 -nodefaults -machine virt,gic-version=host -accel kvm -cpu host -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -device pci-testdev -display none -serial stdio -kernel arm/pmu.flat -smp 1 -append pmu-memaccess-reliability # -initrd /tmp/tmp.ZToqwencZR > > | INFO: PMU version: 0x4 > > | INFO: PMU implementer/ID code: 0(" ")/0 > > | INFO: Implements 6 event counters > > | INFO: pmu: pmu-memaccess-reliability: 32-bit overflows: overflow=0 min=251 max=283 COUNT=250 MARGIN=100 > > | PASS: pmu: pmu-memaccess-reliability: 32-bit overflows: memaccess is reliable > > | SKIP: pmu: pmu-memaccess-reliability: 64-bit overflows: Skip test as 64 overflows need FEAT_PMUv3p5 > > | SUMMARY: 2 tests, 1 skipped > > > > Thanks, > > Mark. > > >
