mirror of https://gitee.com/openkylin/linux.git
0d923820c6
Nest/core pmu units are enabled only when it is used. A reference count is maintained for the events which uses the nest/core pmu units. Currently in *_imc_counters_release function a WARN() is used for notification of any underflow of ref count. The case where event ref count hit a negative value is, when perf session is started, followed by offlining of all cpus in a given core. i.e. in cpuhotplug offline path ppc_core_imc_cpu_offline() function set the ref->count to zero, if the current cpu which is about to offline is the last cpu in a given core and make an OPAL call to disable the engine in that core. And on perf session termination, perf->destroy (core_imc_counters_release) will first decrement the ref->count for this core and based on the ref->count value an opal call is made to disable the core-imc engine. Now, since cpuhotplug path already clears the ref->count for core and disabled the engine, perf->destroy() decrementing again at event termination make it negative which in turn fires the WARN_ON. The same happens for nest units. Add a check to see if the reference count is alreday zero, before decrementing the count, so that the ref count will not hit a negative value. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reviewed-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
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| .. | ||
| req-gen | ||
| 8xx-pmu.c | ||
| Makefile | ||
| bhrb.S | ||
| callchain.c | ||
| core-book3s.c | ||
| core-fsl-emb.c | ||
| e500-pmu.c | ||
| e6500-pmu.c | ||
| hv-24x7-catalog.h | ||
| hv-24x7-domains.h | ||
| hv-24x7.c | ||
| hv-24x7.h | ||
| hv-common.c | ||
| hv-common.h | ||
| hv-gpci-requests.h | ||
| hv-gpci.c | ||
| hv-gpci.h | ||
| imc-pmu.c | ||
| isa207-common.c | ||
| isa207-common.h | ||
| mpc7450-pmu.c | ||
| perf_regs.c | ||
| power4-pmu.c | ||
| power5+-pmu.c | ||
| power5-pmu.c | ||
| power6-pmu.c | ||
| power7-events-list.h | ||
| power7-pmu.c | ||
| power8-events-list.h | ||
| power8-pmu.c | ||
| power9-events-list.h | ||
| power9-pmu.c | ||
| ppc970-pmu.c | ||