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| author | Hendrik Brueckner <brueckner@linux.vnet.ibm.com> | 2016-06-09 12:28:13 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-06-16 12:08:49 +0200 |
| commit | 9254e70c4ef1fee2e5c43feded4433d19cbb6177 (patch) | |
| tree | bce8fe2f460659b40f87e99522c9f85ea613abcf | |
| parent | 1c343f7b0e177e8ca7f4d4a5dd1fa790f85abbcc (diff) | |
| download | op-kernel-dev-9254e70c4ef1fee2e5c43feded4433d19cbb6177.zip op-kernel-dev-9254e70c4ef1fee2e5c43feded4433d19cbb6177.tar.gz | |
s390/cpum_cf: use perf software context for hardware counters
On s390, there are two different hardware PMUs for counting and
sampling. Previously, both PMUs have shared the perf_hw_context
which is not correct and, recently, results in this warning:
------------[ cut here ]------------
WARNING: CPU: 5 PID: 1 at kernel/events/core.c:8485 perf_pmu_register+0x420/0x428
Modules linked in:
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc1+ #2
task: 00000009c5240000 ti: 00000009c5234000 task.ti: 00000009c5234000
Krnl PSW : 0704c00180000000 0000000000220c50 (perf_pmu_register+0x420/0x428)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: ffffffffffffffff 0000000000b15ac6 0000000000000000 00000009cb440000
000000000022087a 0000000000000000 0000000000b78fa0 0000000000000000
0000000000a9aa90 0000000000000084 0000000000000005 000000000088a97a
0000000000000004 0000000000749dd0 000000000022087a 00000009c5237cc0
Krnl Code: 0000000000220c44: a7f4ff54 brc 15,220aec
0000000000220c48: 92011000 mvi 0(%r1),1
#0000000000220c4c: a7f40001 brc 15,220c4e
>0000000000220c50: a7f4ff12 brc 15,220a74
0000000000220c54: 0707 bcr 0,%r7
0000000000220c56: 0707 bcr 0,%r7
0000000000220c58: ebdff0800024 stmg %r13,%r15,128(%r15)
0000000000220c5e: a7f13fe0 tmll %r15,16352
Call Trace:
([<000000000022087a>] perf_pmu_register+0x4a/0x428)
([<0000000000b2c25c>] init_cpum_sampling_pmu+0x14c/0x1f8)
([<0000000000100248>] do_one_initcall+0x48/0x140)
([<0000000000b25d26>] kernel_init_freeable+0x1e6/0x2a0)
([<000000000072bda4>] kernel_init+0x24/0x138)
([<000000000073495e>] kernel_thread_starter+0x6/0xc)
([<0000000000734958>] kernel_thread_starter+0x0/0xc)
Last Breaking-Event-Address:
[<0000000000220c4c>] perf_pmu_register+0x41c/0x428
---[ end trace 0c6ef9f5b771ad97 ]---
Using the perf_sw_context is an option because the cpum_cf PMU does
not use interrupts. To make this more clear, initialize the
capabilities in the PMU structure.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/kernel/perf_cpum_cf.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c index 59215c5..7ec63b1 100644 --- a/arch/s390/kernel/perf_cpum_cf.c +++ b/arch/s390/kernel/perf_cpum_cf.c @@ -649,6 +649,8 @@ static int cpumf_pmu_commit_txn(struct pmu *pmu) /* Performance monitoring unit for s390x */ static struct pmu cpumf_pmu = { + .task_ctx_nr = perf_sw_context, + .capabilities = PERF_PMU_CAP_NO_INTERRUPT, .pmu_enable = cpumf_pmu_enable, .pmu_disable = cpumf_pmu_disable, .event_init = cpumf_pmu_event_init, @@ -708,12 +710,6 @@ static int __init cpumf_pmu_init(void) goto out; } - /* The CPU measurement counter facility does not have overflow - * interrupts to do sampling. Sampling must be provided by - * external means, for example, by timers. - */ - cpumf_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; - cpumf_pmu.attr_groups = cpumf_cf_event_group(); rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", PERF_TYPE_RAW); if (rc) { |
