kernel/linux.git/arch/powerpc/perf/Makefile, branch v7.1

powerpc/vpa_dtl: Add interface to expose vpa dtl counters via perf

2025-09-22T09:18:57+00:00

The pseries Shared Processor Logical Partition(SPLPAR) machines can retrieve a log of dispatch and preempt events from the hypervisor using data from Disptach Trace Log(DTL) buffer. With this information, user can retrieve when and why each dispatch & preempt has occurred. Added an interface to expose the Virtual Processor Area(VPA) DTL counters via perf. The following events are available and exposed in sysfs: vpa_dtl/dtl_cede/ - Trace voluntary (OS initiated) virtual processor waits vpa_dtl/dtl_preempt/ - Trace time slice preempts vpa_dtl/dtl_fault/ - Trace virtual partition memory page faults. vpa_dtl/dtl_all/ - Trace all (dtl_cede/dtl_preempt/dtl_fault) Added interface defines supported event list, config fields for the event attributes and their corresponding bit values which are exported via sysfs. User could use the standard perf tool to access perf events exposed via vpa-dtl pmu. The VPA DTL PMU counters do not interrupt on overflow or generate any PMI interrupts. Therefore, the kernel needs to poll the counters, added hrtimer code to do that. The timer interval can be provided by user via sample_period field in nano seconds. There is one hrtimer added per vpa-dtl pmu thread. To ensure there are no other conflicting dtl users (example: debugfs dtl or /proc/powerpc/vcpudispatch_stats), interface added code to use "down_write_trylock" call to take the dtl_access_lock. The dtl_access_lock is defined in dtl.h file. Also added global reference count variable called "dtl_global_refc", to ensure dtl data can be captured per-cpu. Code also added global lock called "dtl_global_lock" to avoid race condition. Signed-off-by: Kajol Jain Tested-by: Tejas Manhas Tested-by: Venkat Rao Bagalkote Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250915102947.26681-3-atrajeev@linux.ibm.com

kvm powerpc/book3s-apiv2: Introduce kvm-hv specific PMU

2025-04-16T16:46:09+00:00

Introduce a new PMU named 'kvm-hv' inside a new module named 'kvm-hv-pmu' to report Book3s kvm-hv specific performance counters. This will expose KVM-HV specific performance attributes to user-space via kernel's PMU infrastructure and would enableusers to monitor active kvm-hv based guests. The patch creates necessary scaffolding to for the new PMU callbacks and introduces the new kernel module name 'kvm-hv-pmu' which is built with CONFIG_KVM_BOOK3S_HV_PMU. The patch doesn't introduce any perf-events yet, which will be introduced in later patches Signed-off-by: Vaibhav Jain Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250416162740.93143-5-vaibhav@linux.ibm.com

powerpc/perf: Add perf interface to expose vpa counters

2024-11-19T03:11:06+00:00

To support performance measurement for KVM on PowerVM(KoP) feature, PowerVM hypervisor has added couple of new software counters in Virtual Process Area(VPA) of the partition. Commit e1f288d2f9c69 ("KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests") have updated the paca fields with corresponding changes. Proposed perf interface is to expose these new software counters for monitoring of context switch latencies and runtime aggregate. Perf interface driver is called "vpa_pmu" and it has dependency on KVM and perf, hence added new config called "VPA_PMU" which depends on "CONFIG_KVM_BOOK3S_64_HV" and "CONFIG_HV_PERF_CTRS". Since, kvm and kvm_host are currently compiled as built-in modules, this perf interface takes the same path and registered as a module. vpa_pmu perf interface needs access to some of the kvm functions and structures like kvmhv_get_l2_counters_status(), hence kvm_book3s_64.h and kvm_ppc.h are included. Below are the events added to monitor KoP: vpa_pmu/l1_to_l2_lat/ vpa_pmu/l2_to_l1_lat/ vpa_pmu/l2_runtime_agg/ and vpa_pmu driver supports only per-cpu monitoring with this patch. Example usage: [command]# perf stat -e vpa_pmu/l1_to_l2_lat/ -a -I 1000 1.001017682 727,200 vpa_pmu/l1_to_l2_lat/ 2.003540491 1,118,824 vpa_pmu/l1_to_l2_lat/ 3.005699458 1,919,726 vpa_pmu/l1_to_l2_lat/ 4.007827011 2,364,630 vpa_pmu/l1_to_l2_lat/ Signed-off-by: Kajol Jain Co-developed-by: Madhavan Srinivasan Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241118114114.208964-1-kjain@linux.ibm.com

powerpc/perf: Fix 32bit compile

2022-04-21T13:26:47+00:00

The "read_bhrb" global symbol is only called under CONFIG_PPC64 of arch/powerpc/perf/core-book3s.c but it is compiled for both 32 and 64 bit anyway (and LLVM fails to link this on 32bit). This fixes it by moving bhrb.o to obj64 targets. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220421025756.571995-1-aik@ozlabs.ru

powerpc/perf: Simplify Makefile

2021-06-15T07:12:27+00:00

arch/powerpc/Kbuild decend into arch/powerpc/perf/ only when CONFIG_PERF_EVENTS is selected, so there is not need to take CONFIG_PERF_EVENTS into account in arch/powerpc/perf/Makefile. Signed-off-by: Christophe Leroy Reviewed-by: Michal Suchánek Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/d37f61afca55b5b33787b643890e061ae1c18f5f.1620396045.git.christophe.leroy@csgroup.eu

powerpc/perf: power10 Performance Monitoring support

2020-07-22T11:56:41+00:00

Base enablement patch to register performance monitoring hardware support for power10. Patch introduce the raw event encoding format, defines the supported list of events, config fields for the event attributes and their corresponding bit values which are exported via sysfs. Patch also enhances the support function in isa207_common.c to include power10 pmu hardware. Reported-by: kernel test robot Signed-off-by: Madhavan Srinivasan Signed-off-by: Athira Rajeev Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1594996707-3727-9-git-send-email-atrajeev@linux.vnet.ibm.com

powerpc/perf: split callchain.c by bitness

2020-04-02T13:10:00+00:00

Building callchain.c with !COMPAT proved quite ugly with all the defines. Splitting out the 32bit and 64bit parts looks better. No code change intended. Signed-off-by: Michal Suchanek Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a20027bf1074935a7934ee2a6757c99ea047e70d.1584699455.git.msuchanek@suse.de

powerpc/perf: Add generic compat mode pmu driver

2019-05-02T16:54:58+00:00

Most of the power processor generation performance monitoring unit (PMU) driver code is bundled in the kernel and one of those is enabled/registered based on the oprofile_cpu_type check at the boot. But things get little tricky incase of "compat" mode boot. IBM POWER System Server based processors has a compactibility mode feature, which simpily put is, Nth generation processor (lets say POWER8) will act and appear in a mode consistent with an earlier generation (N-1) processor (that is POWER7). And in this "compat" mode boot, kernel modify the "oprofile_cpu_type" to be Nth generation (POWER8). If Nth generation pmu driver is bundled (POWER8), it gets registered. Key dependency here is to have distro support for latest processor performance monitoring support. Patch here adds a generic "compat-mode" performance monitoring driver to be register in absence of powernv platform specific pmu driver. Driver supports only "cycles" and "instruction" events. "0x0001e" used as event code for "cycles" and "0x00002" used as event code for "instruction" events. New file called "generic-compat-pmu.c" is created to contain the driver specific code. And base raw event code format modeled on PPMU_ARCH_207S. Signed-off-by: Madhavan Srinivasan [mpe: Use SPDX tag for license] Signed-off-by: Michael Ellerman

powerpc: Add -Werror at arch/powerpc level

2018-10-18T13:56:17+00:00

Back when I added -Werror in commit ba55bd74360e ("powerpc: Add configurable -Werror for arch/powerpc") I did it by adding it to most of the arch Makefiles. At the time we excluded math-emu, because apparently it didn't build cleanly. But that seems to have been fixed somewhere in the interim. So move the -Werror addition to the top-level of the arch, this saves us from repeating it in every Makefile and means we won't forget to add it to any new sub-dirs. Signed-off-by: Michael Ellerman

powerpc/64s: Remove POWER4 support

2018-03-31T13:47:50+00:00

POWER4 has been broken since at least the change 49d09bf2a6 ("powerpc/64s: Optimise MSR handling in exception handling"), which requires mtmsrd L=1 support. This was introduced in ISA v2.01, and POWER4 supports ISA v2.00. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman