user/sven/linux.git/Documentation/trace, branch v4.19.280

tracing/histogram: Update document for KEYS_MAX size

2022-11-10T16:46:55Z

commit a635beeacc6d56d2b71c39e6c0103f85b53d108e upstream. After commit 4f36c2d85ced ("tracing: Increase tracing map KEYS_MAX size"), 'keys' supports up to three fields. Signed-off-by: Zheng Yejian Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20221017103806.2479139-1-zhengyejian1@huawei.com Signed-off-by: Jonathan Corbet Signed-off-by: Greg Kroah-Hartman

tracing/histogram: Rename "cpu" to "common_cpu"

2021-08-12T11:19:42Z

commit 1e3bac71c5053c99d438771fc9fa5082ae5d90aa upstream. Currently the histogram logic allows the user to write "cpu" in as an event field, and it will record the CPU that the event happened on. The problem with this is that there's a lot of events that have "cpu" as a real field, and using "cpu" as the CPU it ran on, makes it impossible to run histograms on the "cpu" field of events. For example, if I want to have a histogram on the count of the workqueue_queue_work event on its cpu field, running: ># echo 'hist:keys=cpu' > events/workqueue/workqueue_queue_work/trigger Gives a misleading and wrong result. Change the command to "common_cpu" as no event should have "common_*" fields as that's a reserved name for fields used by all events. And this makes sense here as common_cpu would be a field used by all events. Now we can even do: ># echo 'hist:keys=common_cpu,cpu if cpu < 100' > events/workqueue/workqueue_queue_work/trigger ># cat events/workqueue/workqueue_queue_work/hist # event histogram # # trigger info: hist:keys=common_cpu,cpu:vals=hitcount:sort=hitcount:size=2048 if cpu < 100 [active] # { common_cpu: 0, cpu: 2 } hitcount: 1 { common_cpu: 0, cpu: 4 } hitcount: 1 { common_cpu: 7, cpu: 7 } hitcount: 1 { common_cpu: 0, cpu: 7 } hitcount: 1 { common_cpu: 0, cpu: 1 } hitcount: 1 { common_cpu: 0, cpu: 6 } hitcount: 2 { common_cpu: 0, cpu: 5 } hitcount: 2 { common_cpu: 1, cpu: 1 } hitcount: 4 { common_cpu: 6, cpu: 6 } hitcount: 4 { common_cpu: 5, cpu: 5 } hitcount: 14 { common_cpu: 4, cpu: 4 } hitcount: 26 { common_cpu: 0, cpu: 0 } hitcount: 39 { common_cpu: 2, cpu: 2 } hitcount: 184 Now for backward compatibility, I added a trick. If "cpu" is used, and the field is not found, it will fall back to "common_cpu" and work as it did before. This way, it will still work for old programs that use "cpu" to get the actual CPU, but if the event has a "cpu" as a field, it will get that event's "cpu" field, which is probably what it wants anyway. I updated the tracefs/README to include documentation about both the common_timestamp and the common_cpu. This way, if that text is present in the README, then an application can know that common_cpu is supported over just plain "cpu". Link: https://lkml.kernel.org/r/20210721110053.26b4f641@oasis.local.home Cc: Namhyung Kim Cc: Ingo Molnar Cc: Andrew Morton Cc: stable@vger.kernel.org Fixes: 8b7622bf94a44 ("tracing: Add cpu field for hist triggers") Reviewed-by: Tom Zanussi Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tweewide: Fix most Shebang lines

2021-05-22T08:59:50Z

commit c25ce589dca10d64dde139ae093abc258a32869c upstream. Change every shebang which does not need an argument to use /usr/bin/env. This is needed as not every distro has everything under /usr/bin, sometimes not even bash. Signed-off-by: Finn Behrens Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

Merge tag 'docs-4.19' of git://git.lwn.net/linux

2018-08-14T21:29:31Z

Pull documentation update from Jonathan Corbet: "This was a moderately busy cycle for docs, with the usual collection of small fixes and updates. We also have new ktime_get_*() docs from Arnd, some kernel-doc fixes, a new set of Italian translations (non so se vale la pena, ma non fa male - speriamo bene), and some extensive early memory-management documentation improvements from Mike Rapoport" * tag 'docs-4.19' of git://git.lwn.net/linux: (52 commits) Documentation: corrections to console/console.txt Documentation: add ioctl number entry for v4l2-subdev.h Remove gendered language from management style documentation scripts/kernel-doc: Escape all literal braces in regexes docs/mm: add description of boot time memory management docs/mm: memblock: add overview documentation docs/mm: memblock: add kernel-doc description for memblock types docs/mm: memblock: add kernel-doc comments for memblock_add[_node] docs/mm: memblock: update kernel-doc comments mm/memblock: add a name for memblock flags enumeration docs/mm: bootmem: add overview documentation docs/mm: bootmem: add kernel-doc description of 'struct bootmem_data' docs/mm: bootmem: fix kernel-doc warnings docs/mm: nobootmem: fixup kernel-doc comments mm/bootmem: drop duplicated kernel-doc comments Documentation: vm.txt: Adding 'nr_hugepages_mempolicy' parameter description. doc:it_IT: translation for kernel-hacking docs: Fix the reference labels in Locking.rst doc: tracing: Fix a typo of trace_stat mm: Introduce new type vm_fault_t ...

doc: tracing: Fix a typo of trace_stat

2018-07-26T21:48:10Z

The name of the directory for per-cpu function statistics is trace_stat, not trace_stats. Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt (VMware) Signed-off-by: Jonathan Corbet

cpufreq: trace frequency limits change

2018-07-26T08:17:47Z

systrace used for tracing for Android systems has carried a patch for many years in the Android tree that traces when the cpufreq limits change. With the help of this information, systrace can know when the policy limits change and can visually display the data. Lets add upstream support for the same. Signed-off-by: Ruchi Kandoi Signed-off-by: Joel Fernandes (Google) Acked-by: Viresh Kumar Acked-by: Steven Rostedt (VMware) Signed-off-by: Rafael J. Wysocki

Documentation: kprobetrace: document 'trigger' file

2018-07-23T15:26:42Z

As the other files are documented explicitly, let's add a short description for 'trigger' as well. Signed-off-by: Andreas Ziegler Signed-off-by: Jonathan Corbet

Documentation: {u,k}probes: fix filename for event enabling

2018-07-23T15:26:37Z

The per-event files to enable or disable kprobes and uprobes are named 'enable', not 'enabled'. Fix the corresponding documentation. Signed-off-by: Andreas Ziegler Signed-off-by: Jonathan Corbet

docs: histogram.txt: convert it to ReST file format

2018-07-02T17:26:02Z

Despite being mentioned at Documentation/trace/ftrace.rst as a rst file, this file was still a text one, with several issues. Convert it to ReST and add it to the trace index: - Mark the document title as such; - Identify and indent the literal blocks; - Use the proper markups for table. Signed-off-by: Mauro Carvalho Chehab Acked-by: Steven Rostedt (VMware) Signed-off-by: Jonathan Corbet

tracing: Fix some errors in histogram documentation

2018-06-21T19:12:44Z

Fix typos, inconsistencies in using quotes, incorrect section number, etc. in the trace histogram documentation. Link: http://lkml.kernel.org/r/20180614224859.55864-1-joel@joelfernandes.org Reviewed-by: Masami Hiramatsu Acked-by: Tom Zanussi Signed-off-by: Joel Fernandes (Google) Signed-off-by: Steven Rostedt (VMware)