perf-stat(1) ============ NAME ---- perf-stat - Run a command and gather performance counter statistics SYNOPSIS -------- [verse] 'perf stat' [-e | --event=EVENT] [-a] 'perf stat' [-e | --event=EVENT] [-a] -- [] 'perf stat' [-e | --event=EVENT] [-a] record [-o file] -- [] 'perf stat' report [-i file] DESCRIPTION ----------- This command runs a command and gathers performance counter statistics from it. OPTIONS ------- ...:: Any command you can specify in a shell. record:: See STAT RECORD. report:: See STAT REPORT. -e:: --event=:: Select the PMU event. Selection can be: - a symbolic event name (use 'perf list' to list all events) - a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a hexadecimal event descriptor. - a symbolically formed event like 'pmu/param1=0x3,param2/' where param1 and param2 are defined as formats for the PMU in /sys/bus/event_sources/devices//format/* - a symbolically formed event like 'pmu/config=M,config1=N,config2=K/' where M, N, K are numbers (in decimal, hex, octal format). Acceptable values for each of 'config', 'config1' and 'config2' parameters are defined by corresponding entries in /sys/bus/event_sources/devices//format/* -i:: --no-inherit:: child tasks do not inherit counters -p:: --pid=:: stat events on existing process id (comma separated list) -t:: --tid=:: stat events on existing thread id (comma separated list) -a:: --all-cpus:: system-wide collection from all CPUs -c:: --scale:: scale/normalize counter values -d:: --detailed:: print more detailed statistics, can be specified up to 3 times -d: detailed events, L1 and LLC data cache -d -d: more detailed events, dTLB and iTLB events -d -d -d: very detailed events, adding prefetch events -r:: --repeat=:: repeat command and print average + stddev (max: 100). 0 means forever. -B:: --big-num:: print large numbers with thousands' separators according to locale -C:: --cpu=:: Count only on the list of CPUs provided. Multiple CPUs can be provided as a comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2. In per-thread mode, this option is ignored. The -a option is still necessary to activate system-wide monitoring. Default is to count on all CPUs. -A:: --no-aggr:: Do not aggregate counts across all monitored CPUs in system-wide mode (-a). This option is only valid in system-wide mode. -n:: --null:: null run - don't start any counters -v:: --verbose:: be more verbose (show counter open errors, etc) -x SEP:: --field-separator SEP:: print counts using a CSV-style output to make it easy to import directly into spreadsheets. Columns are separated by the string specified in SEP. -G name:: --cgroup name:: monitor only in the container (cgroup) called "name". This option is available only in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to container "name" are monitored when they run on the monitored CPUs. Multiple cgroups can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup to first event, second cgroup to second event and so on. It is possible to provide an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have corresponding events, i.e., they always refer to events defined earlier on the command line. -o file:: --output file:: Print the output into the designated file. --append:: Append to the output file designated with the -o option. Ignored if -o is not specified. --log-fd:: Log output to fd, instead of stderr. Complementary to --output, and mutually exclusive with it. --append may be used here. Examples: 3>results perf stat --log-fd 3 -- $cmd 3>>results perf stat --log-fd 3 --append -- $cmd --pre:: --post:: Pre and post measurement hooks, e.g.: perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage -I msecs:: --interval-print msecs:: Print count deltas every N milliseconds (minimum: 10ms) The overhead percentage could be high in some cases, for instance with small, sub 100ms intervals. Use with caution. example: 'perf stat -I 1000 -e cycles -a sleep 5' --metric-only:: Only print computed metrics. Print them in a single line. Don't show any raw values. Not supported with --per-thread. --per-socket:: Aggregate counts per processor socket for system-wide mode measurements. This is a useful mode to detect imbalance between sockets. To enable this mode, use --per-socket in addition to -a. (system-wide). The output includes the socket number and the number of online processors on that socket. This is useful to gauge the amount of aggregation. --per-core:: Aggregate counts per physical processor for system-wide mode measurements. This is a useful mode to detect imbalance between physical cores. To enable this mode, use --per-core in addition to -a. (system-wide). The output includes the core number and the number of online logical processors on that physical processor. --per-thread:: Aggregate counts per monitored threads, when monitoring threads (-t option) or processes (-p option). -D msecs:: --delay msecs:: After starting the program, wait msecs before measuring. This is useful to filter out the startup phase of the program, which is often very different. -T:: --transaction:: Print statistics of transactional execution if supported. STAT RECORD ----------- Stores stat data into perf data file. -o file:: --output file:: Output file name. STAT REPORT ----------- Reads and reports stat data from perf data file. -i file:: --input file:: Input file name. --per-socket:: Aggregate counts per processor socket for system-wide mode measurements. --per-core:: Aggregate counts per physical processor for system-wide mode measurements. -A:: --no-aggr:: Do not aggregate counts across all monitored CPUs. --topdown:: Print top down level 1 metrics if supported by the CPU. This allows to determine bottle necks in the CPU pipeline for CPU bound workloads, by breaking the cycles consumed down into frontend bound, backend bound, bad speculation and retiring. Frontend bound means that the CPU cannot fetch and decode instructions fast enough. Backend bound means that computation or memory access is the bottle neck. Bad Speculation means that the CPU wasted cycles due to branch mispredictions and similar issues. Retiring means that the CPU computed without an apparently bottleneck. The bottleneck is only the real bottleneck if the workload is actually bound by the CPU and not by something else. For best results it is usually a good idea to use it with interval mode like -I 1000, as the bottleneck of workloads can change often. The top down metrics are collected per core instead of per CPU thread. Per core mode is automatically enabled and -a (global monitoring) is needed, requiring root rights or perf.perf_event_paranoid=-1. Topdown uses the full Performance Monitoring Unit, and needs disabling of the NMI watchdog (as root): echo 0 > /proc/sys/kernel/nmi_watchdog for best results. Otherwise the bottlenecks may be inconsistent on workload with changing phases. This enables --metric-only, unless overriden with --no-metric-only. To interpret the results it is usually needed to know on which CPUs the workload runs on. If needed the CPUs can be forced using taskset. EXAMPLES -------- $ perf stat -- make -j Performance counter stats for 'make -j': 8117.370256 task clock ticks # 11.281 CPU utilization factor 678 context switches # 0.000 M/sec 133 CPU migrations # 0.000 M/sec 235724 pagefaults # 0.029 M/sec 24821162526 CPU cycles # 3057.784 M/sec 18687303457 instructions # 2302.138 M/sec 172158895 cache references # 21.209 M/sec 27075259 cache misses # 3.335 M/sec Wall-clock time elapsed: 719.554352 msecs CSV FORMAT ---------- With -x, perf stat is able to output a not-quite-CSV format output Commas in the output are not put into "". To make it easy to parse it is recommended to use a different character like -x \; The fields are in this order: - optional usec time stamp in fractions of second (with -I xxx) - optional CPU, core, or socket identifier - optional number of logical CPUs aggregated - counter value - unit of the counter value or empty - event name - run time of counter - percentage of measurement time the counter was running - optional variance if multiple values are collected with -r - optional metric value - optional unit of metric Additional metrics may be printed with all earlier fields being empty. SEE ALSO -------- linkperf:perf-top[1], linkperf:perf-list[1] - Introduce CONFIG_PCI_DRIVERS_LEGACY - Support generic drivers CPC - Convert bare 'unsigned' to 'unsigned int' - Avoid lock when MIPS CM >= 3 is present GIC: - Delete unused file smp-gic.c mt7620: - Delete unnecessary assignment for the field "owner" from PCI BCM63xx: - Let clk_disable() return immediately if clk is NULL pm-cps: - Change FSB workaround to CPU blacklist - Update comments on barrier instructions - Use MIPS standard lightweight ordering barrier - Use MIPS standard completion barrier - Remove selection of sync types - Add MIPSr6 CPU support - Support CM3 changes to Coherence Enable Register SMP: - Wrap call to mips_cpc_lock_other in mips_cm_lock_other - Introduce mechanism for freeing and allocating IPIs cpuidle: - cpuidle-cps: Enable use with MIPSr6 CPUs. SEAD3: - Rewrite to use DT and generic kernel feature. USB: - host: ehci-sead3: Remove SEAD-3 EHCI code FBDEV: - cobalt_lcdfb: Drop SEAD3 support dt-bindings: - Document a binding for simple ASCII LCDs auxdisplay: - img-ascii-lcd: driver for simple ASCII LCD displays irqchip i8259: - i8259: Add domain before mapping parent irq - i8259: Allow platforms to override poll function - i8259: Remove unused i8259A_irq_pending Malta: - Rewrite to use DT of/platform: - Probe "isa" busses by default CM: - Print CM error reports upon bus errors Module: - Migrate exception table users off module.h and onto extable.h - Make various drivers explicitly non-modular: - Audit and remove any unnecessary uses of module.h mailmap: - Canonicalize to Qais' current email address. Documentation: - MIPS supports HAVE_REGS_AND_STACK_ACCESS_API Loongson1C: - Add CPU support for Loongson1C - Add board support - Add defconfig - Add RTC support for Loongson1C board All this except one Documentation fix has sat in linux-next and has survived Imagination's automated build test system" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (127 commits) Documentation: MIPS supports HAVE_REGS_AND_STACK_ACCESS_API MIPS: ptrace: Fix regs_return_value for kernel context MIPS: VDSO: Drop duplicated -I*/-E* aflags MIPS: Fix -mabi=64 build of vdso.lds MIPS: Enable hardened usercopy MIPS: generic: Convert SEAD-3 to a generic board MIPS: generic: Introduce generic DT-based board support MIPS: Support generating Flattened Image Trees (.itb) MIPS: Adjust MIPS64 CAC_BASE to reflect Config.K0 MIPS: Print CM error reports upon bus errors MIPS: Support per-device DMA coherence MIPS: dma-default: Don't check hw_coherentio if device is non-coherent MIPS: Sanitise coherentio semantics MIPS: PCI: Support generic drivers MIPS: PCI: Introduce CONFIG_PCI_DRIVERS_LEGACY MIPS: PCI: Split pci.c into pci.c & pci-legacy.c MIPS: PCI: Inline pcibios_assign_all_busses MIPS: PCI: Make pcibios_set_cache_line_size an initcall MIPS: PCI: Support for CONFIG_PCI_DOMAINS_GENERIC MIPS: PCI: Use struct list_head lists ...
Diffstat (limited to 'drivers/usb/dwc2')