diff options
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/perf-arm-spe.txt | 12 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-report.txt | 9 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-sched.txt | 36 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-script.txt | 7 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-test.txt | 13 |
5 files changed, 72 insertions, 5 deletions
diff --git a/tools/perf/Documentation/perf-arm-spe.txt b/tools/perf/Documentation/perf-arm-spe.txt index bf03222e9a..0a3eda4823 100644 --- a/tools/perf/Documentation/perf-arm-spe.txt +++ b/tools/perf/Documentation/perf-arm-spe.txt @@ -116,6 +116,15 @@ Depending on CPU model, the kernel may need to be booted with page table isolati (kpti=off). If KPTI needs to be disabled, this will fail with a console message "profiling buffer inaccessible. Try passing 'kpti=off' on the kernel command line". +For the full criteria that determine whether KPTI needs to be forced off or not, see function +unmap_kernel_at_el0() in the kernel sources. Common cases where it's not required +are on the CPUs in kpti_safe_list, or on Arm v8.5+ where FEAT_E0PD is mandatory. + +The SPE interrupt must also be described by the firmware. If the module is loaded and KPTI is +disabled (or isn't required to be disabled) but the SPE PMU still doesn't show in +/sys/bus/event_source/devices/, then it's possible that the SPE interrupt isn't described by +ACPI or DT. In this case no warning will be printed by the driver. + Capturing SPE with perf command-line tools ------------------------------------------ @@ -199,7 +208,8 @@ Common errors - "Cannot find PMU `arm_spe'. Missing kernel support?" - Module not built or loaded, KPTI not disabled (see above), or running on a VM + Module not built or loaded, KPTI not disabled, interrupt not described by firmware, + or running on a VM. See 'Kernel Requirements' above. - "Arm SPE CONTEXT packets not found in the traces." diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt index d8b863e01f..d2b1593ef7 100644 --- a/tools/perf/Documentation/perf-report.txt +++ b/tools/perf/Documentation/perf-report.txt @@ -121,6 +121,9 @@ OPTIONS - type: Data type of sample memory access. - typeoff: Offset in the data type of sample memory access. - symoff: Offset in the symbol. + - weight1: Average value of event specific weight (1st field of weight_struct). + - weight2: Average value of event specific weight (2nd field of weight_struct). + - weight3: Average value of event specific weight (3rd field of weight_struct). By default, comm, dso and symbol keys are used. (i.e. --sort comm,dso,symbol) @@ -198,7 +201,11 @@ OPTIONS --fields=:: Specify output field - multiple keys can be specified in CSV format. Following fields are available: - overhead, overhead_sys, overhead_us, overhead_children, sample and period. + overhead, overhead_sys, overhead_us, overhead_children, sample, period, + weight1, weight2, weight3, ins_lat, p_stage_cyc and retire_lat. The + last 3 names are alias for the corresponding weights. When the weight + fields are used, they will show the average value of the weight. + Also it can contain any sort key(s). By default, every sort keys not specified in -F will be appended diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt index 5fbe42bd59..a216d2991b 100644 --- a/tools/perf/Documentation/perf-sched.txt +++ b/tools/perf/Documentation/perf-sched.txt @@ -20,6 +20,26 @@ There are several variants of 'perf sched': 'perf sched latency' to report the per task scheduling latencies and other scheduling properties of the workload. + Example usage: + perf sched record -- sleep 1 + perf sched latency + + ------------------------------------------------------------------------------------------------------------------------------------------- + Task | Runtime ms | Count | Avg delay ms | Max delay ms | Max delay start | Max delay end | + ------------------------------------------------------------------------------------------------------------------------------------------- + perf:(2) | 2.804 ms | 66 | avg: 0.524 ms | max: 1.069 ms | max start: 254752.314960 s | max end: 254752.316029 s + NetworkManager:1343 | 0.372 ms | 13 | avg: 0.008 ms | max: 0.013 ms | max start: 254751.551153 s | max end: 254751.551166 s + kworker/1:2-xfs:4649 | 0.012 ms | 1 | avg: 0.008 ms | max: 0.008 ms | max start: 254751.519807 s | max end: 254751.519815 s + kworker/3:1-xfs:388 | 0.011 ms | 1 | avg: 0.006 ms | max: 0.006 ms | max start: 254751.519809 s | max end: 254751.519815 s + sleep:147736 | 0.938 ms | 3 | avg: 0.006 ms | max: 0.007 ms | max start: 254751.313817 s | max end: 254751.313824 s + + It shows Runtime(time that a task spent actually running on the CPU), + Count(number of times a delay was calculated) and delay(time that a + task was ready to run but was kept waiting). + + Tasks with the same command name are merged and the merge count is + given within (), However if -p option is used, pid is mentioned. + 'perf sched script' to see a detailed trace of the workload that was recorded (aliased to 'perf script' for now). @@ -78,6 +98,22 @@ OPTIONS --force:: Don't complain, do it. +OPTIONS for 'perf sched latency' +------------------------------- + +-C:: +--CPU <n>:: + CPU to profile on. + +-p:: +--pids:: + latency stats per pid instead of per command name. + +-s:: +--sort <key[,key2...]>:: + sort by key(s): runtime, switch, avg, max + by default it's sorted by "avg ,max ,switch ,runtime". + OPTIONS for 'perf sched map' ---------------------------- diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt index 005e51df85..ff086ef05a 100644 --- a/tools/perf/Documentation/perf-script.txt +++ b/tools/perf/Documentation/perf-script.txt @@ -132,9 +132,9 @@ OPTIONS Comma separated list of fields to print. Options are: comm, tid, pid, time, cpu, event, trace, ip, sym, dso, dsoff, addr, symoff, srcline, period, iregs, uregs, brstack, brstacksym, flags, bpf-output, - brstackinsn, brstackinsnlen, brstackoff, callindent, insn, disasm, + brstackinsn, brstackinsnlen, brstackdisasm, brstackoff, callindent, insn, disasm, insnlen, synth, phys_addr, metric, misc, srccode, ipc, data_page_size, - code_page_size, ins_lat, machine_pid, vcpu, cgroup, retire_lat. + code_page_size, ins_lat, machine_pid, vcpu, cgroup, retire_lat, Field list can be prepended with the type, trace, sw or hw, to indicate to which event type the field list applies. @@ -257,6 +257,9 @@ OPTIONS can’t know the next sequential instruction after an unconditional branch unless you calculate that based on its length. + brstackdisasm acts like brstackinsn, but will print disassembled instructions if + perf is built with the capstone library. + The brstackoff field will print an offset into a specific dso/binary. With the metric option perf script can compute metrics for diff --git a/tools/perf/Documentation/perf-test.txt b/tools/perf/Documentation/perf-test.txt index 951a2f2628..9acb8d1f65 100644 --- a/tools/perf/Documentation/perf-test.txt +++ b/tools/perf/Documentation/perf-test.txt @@ -31,9 +31,20 @@ OPTIONS --verbose:: Be more verbose. +-S:: +--sequential:: + Run tests one after the other, this is the default mode. + +-p:: +--parallel:: + Run tests in parallel, speeds up the whole process but is not safe with + the current infrastructure, where some tests that compete for some resources, + for instance, 'perf probe' tests that add/remove probes or clean all probes, etc. + -F:: --dont-fork:: - Do not fork child for each test, run all tests within single process. + Do not fork child for each test, run all tests within single process, this + sets sequential mode. --dso:: Specify a DSO for the "Symbols" test. |