[PATCH] selftests/powerpc: Use write_pmc instead of count_pmc to reset PMCs at the end of ebb selftests

Desnes A. Nunes do Rosario desnesn at linux.ibm.com
Thu Nov 28 07:51:26 AEDT 2019


By using count_pmc() to reset the pmc instead of write_pmc(), an extra
count is performed on ebb_state.stats.pmc_count[PMC_INDEX(pmc)] more than
the value accounted by ebb_state.stats.ebb_count in the main test loops.
This extra pmc_count makes a few tests fail occasionally on PowerVM systems
with high workloads, such as cycles_test shown hereafter, where the
ebb_count is occasionally above the upper limit due to this extra count.

Moreover, this is also indicated by extra PMC1 trace_log on the output of
a few tests:

==========
   ...
   [21]: counter = 8
   [22]: register SPRN_MMCR0 = 0x0000000080000080
   [23]: register SPRN_PMC1  = 0x0000000080000004
   [24]: counter = 9
   [25]: register SPRN_MMCR0 = 0x0000000080000080
   [26]: register SPRN_PMC1  = 0x0000000080000004
   [27]: counter = 10
   [28]: register SPRN_MMCR0 = 0x0000000080000080
   [29]: register SPRN_PMC1  = 0x0000000080000004
>> [30]: register SPRN_PMC1  = 0x000000004000051e
PMC1 count (0x280000546) above upper limit 0x2800003e8 (+0x15e)
[FAIL] Test FAILED on line 52
failure: cycles
==========

Signed-off-by: Desnes A. Nunes do Rosario <desnesn at linux.ibm.com>
---
 .../powerpc/pmu/ebb/back_to_back_ebbs_test.c         |  2 +-
 .../testing/selftests/powerpc/pmu/ebb/cycles_test.c  |  2 +-
 .../powerpc/pmu/ebb/cycles_with_freeze_test.c        |  2 +-
 .../powerpc/pmu/ebb/cycles_with_mmcr2_test.c         |  2 +-
 tools/testing/selftests/powerpc/pmu/ebb/ebb.c        |  2 +-
 .../powerpc/pmu/ebb/ebb_on_willing_child_test.c      |  2 +-
 .../selftests/powerpc/pmu/ebb/lost_exception_test.c  |  2 +-
 .../selftests/powerpc/pmu/ebb/multi_counter_test.c   | 12 ++++++------
 .../selftests/powerpc/pmu/ebb/multi_ebb_procs_test.c |  2 +-
 .../selftests/powerpc/pmu/ebb/pmae_handling_test.c   |  2 +-
 .../selftests/powerpc/pmu/ebb/pmc56_overflow_test.c  |  2 +-
 11 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c b/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c
index a2d7b0e3dca9..f133ab425f10 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c
@@ -91,7 +91,7 @@ int back_to_back_ebbs(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/cycles_test.c b/tools/testing/selftests/powerpc/pmu/ebb/cycles_test.c
index bc893813483e..14a399a64729 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/cycles_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/cycles_test.c
@@ -42,7 +42,7 @@ int cycles(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_freeze_test.c b/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_freeze_test.c
index dcd351d20328..0f2089f6f82c 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_freeze_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_freeze_test.c
@@ -99,7 +99,7 @@ int cycles_with_freeze(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c b/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c
index 94c99c12c0f2..a8f3bee04cd8 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c
@@ -71,7 +71,7 @@ int cycles_with_mmcr2(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/ebb.c b/tools/testing/selftests/powerpc/pmu/ebb/ebb.c
index dfbc5c3ad52d..bf6f25dfcf7b 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/ebb.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/ebb.c
@@ -396,7 +396,7 @@ int ebb_child(union pipe read_pipe, union pipe write_pipe)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/ebb_on_willing_child_test.c b/tools/testing/selftests/powerpc/pmu/ebb/ebb_on_willing_child_test.c
index ca2f7d729155..513812cdcca1 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/ebb_on_willing_child_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/ebb_on_willing_child_test.c
@@ -38,7 +38,7 @@ static int victim_child(union pipe read_pipe, union pipe write_pipe)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/lost_exception_test.c b/tools/testing/selftests/powerpc/pmu/ebb/lost_exception_test.c
index ac3e6e182614..5979606c41dc 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/lost_exception_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/lost_exception_test.c
@@ -75,7 +75,7 @@ static int test_body(void)
 	ebb_freeze_pmcs();
 	ebb_global_disable();
 
-	count_pmc(4, sample_period);
+	write_pmc(4, pmc_sample_period(sample_period));
 	mtspr(SPRN_PMC4, 0xdead);
 
 	dump_summary_ebb_state();
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/multi_counter_test.c b/tools/testing/selftests/powerpc/pmu/ebb/multi_counter_test.c
index b8242e9d97d2..227827b665d5 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/multi_counter_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/multi_counter_test.c
@@ -70,12 +70,12 @@ int multi_counter(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
-	count_pmc(2, sample_period);
-	count_pmc(3, sample_period);
-	count_pmc(4, sample_period);
-	count_pmc(5, sample_period);
-	count_pmc(6, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
+	write_pmc(2, pmc_sample_period(sample_period));
+	write_pmc(3, pmc_sample_period(sample_period));
+	write_pmc(4, pmc_sample_period(sample_period));
+	write_pmc(5, pmc_sample_period(sample_period));
+	write_pmc(6, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/multi_ebb_procs_test.c b/tools/testing/selftests/powerpc/pmu/ebb/multi_ebb_procs_test.c
index a05c0e18ded6..ade70bed0499 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/multi_ebb_procs_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/multi_ebb_procs_test.c
@@ -61,7 +61,7 @@ static int cycles_child(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_summary_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c b/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c
index 153ebc92234f..7b4bf4ed12cb 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c
@@ -82,7 +82,7 @@ static int test_body(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(1, sample_period);
+	write_pmc(1, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c b/tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c
index eadad75ed7e6..bb55af71404d 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c
@@ -76,7 +76,7 @@ int pmc56_overflow(void)
 	ebb_global_disable();
 	ebb_freeze_pmcs();
 
-	count_pmc(2, sample_period);
+	write_pmc(2, pmc_sample_period(sample_period));
 
 	dump_ebb_state();
 
-- 
2.21.0



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