diff options
| author | Athira Rajeev <atrajeev@linux.vnet.ibm.com> | 2021-04-06 12:16:01 -0400 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-08 21:17:44 +1000 |
| commit | 10f8f96179ecc7f69c927f6d231f6d02736cea83 (patch) | |
| tree | 73542f9f9787056244d834af2bd502033460ad61 /arch | |
| parent | 812aa68ef7d4d71bed996468ead665092a3f8de9 (diff) | |
powerpc/perf: Fix PMU constraint check for EBB events
The power PMU group constraints includes check for EBB events to make
sure all events in a group must agree on EBB. This will prevent
scheduling EBB and non-EBB events together. But in the existing check,
settings for constraint mask and value is interchanged. Patch fixes the
same.
Before the patch, PMU selftest "cpu_event_pinned_vs_ebb_test" fails with
below in dmesg logs. This happens because EBB event gets enabled along
with a non-EBB cpu event.
[35600.453346] cpu_event_pinne[41326]: illegal instruction (4)
at 10004a18 nip 10004a18 lr 100049f8 code 1 in
cpu_event_pinned_vs_ebb_test[10000000+10000]
Test results after the patch:
$ ./pmu/ebb/cpu_event_pinned_vs_ebb_test
test: cpu_event_pinned_vs_ebb
tags: git_version:v5.12-rc5-93-gf28c3125acd3-dirty
Binding to cpu 8
EBB Handler is at 0x100050c8
read error on event 0x7fffe6bd4040!
PM_RUN_INST_CMPL: result 9872 running/enabled 37930432
success: cpu_event_pinned_vs_ebb
This bug was hidden by other logic until commit 1908dc911792 (perf:
Tweak perf_event_attr::exclusive semantics).
Fixes: 4df489991182 ("powerpc/perf: Add power8 EBB support")
Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Mention commit 1908dc911792]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1617725761-1464-1-git-send-email-atrajeev@linux.vnet.ibm.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/perf/isa207-common.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c index e4f577da33d8..8b5eeb6fb2fb 100644 --- a/arch/powerpc/perf/isa207-common.c +++ b/arch/powerpc/perf/isa207-common.c @@ -447,8 +447,8 @@ ebb_bhrb: * EBB events are pinned & exclusive, so this should never actually * hit, but we leave it as a fallback in case. */ - mask |= CNST_EBB_VAL(ebb); - value |= CNST_EBB_MASK; + mask |= CNST_EBB_MASK; + value |= CNST_EBB_VAL(ebb); *maskp = mask; *valp = value; |