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9 dayssched/tracing: Append prev_state to tp args insteadDelyan Kratunov
Commit fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting sched_switch event, 2022-01-20) added a new prev_state argument to the sched_switch tracepoint, before the prev task_struct pointer. This reordering of arguments broke BPF programs that use the raw tracepoint (e.g. tp_btf programs). The type of the second argument has changed and existing programs that assume a task_struct* argument (e.g. for bpf_task_storage access) will now fail to verify. If we instead append the new argument to the end, all existing programs would continue to work and can conditionally extract the prev_state argument on supported kernel versions. Fixes: fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting sched_switch event, 2022-01-20) Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/c8a6930dfdd58a4a5755fc01732675472979732b.camel@fb.com
2022-03-23Merge tag 'trace-v5.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - New user_events interface. User space can register an event with the kernel describing the format of the event. Then it will receive a byte in a page mapping that it can check against. A privileged task can then enable that event like any other event, which will change the mapped byte to true, telling the user space application to start writing the event to the tracing buffer. - Add new "ftrace_boot_snapshot" kernel command line parameter. When set, the tracing buffer will be saved in the snapshot buffer at boot up when the kernel hands things over to user space. This will keep the traces that happened at boot up available even if user space boot up has tracing as well. - Have TRACE_EVENT_ENUM() also update trace event field type descriptions. Thus if a static array defines its size with an enum, the user space trace event parsers can still know how to parse that array. - Add new TRACE_CUSTOM_EVENT() macro. This acts the same as the TRACE_EVENT() macro, but will attach to an existing tracepoint. This will make one tracepoint be able to trace different content and not be stuck at only what the original TRACE_EVENT() macro exports. - Fixes to tracing error logging. - Better saving of cmdlines to PIDs when tracing (use the wakeup events for mapping). * tag 'trace-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (30 commits) tracing: Have type enum modifications copy the strings user_events: Add trace event call as root for low permission cases tracing/user_events: Use alloc_pages instead of kzalloc() for register pages tracing: Add snapshot at end of kernel boot up tracing: Have TRACE_DEFINE_ENUM affect trace event types as well tracing: Fix strncpy warning in trace_events_synth.c user_events: Prevent dyn_event delete racing with ioctl add/delete tracing: Add TRACE_CUSTOM_EVENT() macro tracing: Move the defines to create TRACE_EVENTS into their own files tracing: Add sample code for custom trace events tracing: Allow custom events to be added to the tracefs directory tracing: Fix last_cmd_set() string management in histogram code user_events: Fix potential uninitialized pointer while parsing field tracing: Fix allocation of last_cmd in last_cmd_set() user_events: Add documentation file user_events: Add sample code for typical usage user_events: Add self-test for validator boundaries user_events: Add self-test for perf_event integration user_events: Add self-test for dynamic_events integration user_events: Add self-test for ftrace integration ...
2022-03-11tracing: Add TRACE_CUSTOM_EVENT() macroSteven Rostedt (Google)
To make it really easy to add custom events from modules, add a TRACE_CUSTOM_EVENT() macro that acts just like the TRACE_EVENT() macro, but creates a custom event to an already existing tracepoint. The trace_custom_sched.[ch] has been updated to use this new macro to show how simple it is. Link: https://lkml.kernel.org/r/20220303220625.738622494@goodmis.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-11tracing: Add sample code for custom trace eventsSteven Rostedt (Google)
Add sample code to show how to create custom trace events in the tracefs directory that can be enabled and modified like any event in tracefs (including triggers, histograms, synthetic events and event probes). The example is creating a custom sched_switch and a sched_waking to limit what is recorded: If the custom sched switch only records the prev_prio, next_prio and next_pid, it can bring the size from 64 bytes per event, down to just 16 bytes! If sched_waking only records the prio and pid of the woken event, it will bring the size down from 36 bytes to 12 bytes per event. This will allow for a much smaller footprint into the ring buffer and keep more events from dropping. Link: https://lkml.kernel.org/r/20220303220625.369226746@goodmis.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Suggested-by: Joel Fernandes <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-13tracing: Fix mismatched comment in __string_lenGeliang Tang
Here __assign_str_len() should be used for the __string_len type, instead of __assign_str() in the comment. Link: https://lkml.kernel.org/r/5c012db463392d0e6d4f0636203d778962ad060a.1640170494.git.geliang.tang@suse.com Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 883b4aee4dec6 ("tracing: Add trace_event helper macros __string_len() and __assign_str_len()") Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2021-12-06samples/trace_event: Add '__rel_loc' using sample eventMasami Hiramatsu
Add '__rel_loc' using sample event for testing. User can use this for testing purpose. There is no reason to use this macro from the kernel. Link: https://lkml.kernel.org/r/163757343050.510314.2876529802471645178.stgit@devnote2 Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-17tracing: Add trace_event helper macros __string_len() and __assign_str_len()Steven Rostedt (VMware)
There's a few cases that a string that is to be recorded in a trace event, does not have a terminating 'nul' character, and instead, the tracepoint passes in the length of the string to record. Add two helper macros to the trace event code that lets this work easier, than tricks with "%.*s" logic. __string_len() which is similar to __string() for declaration, but takes a length argument. __assign_str_len() which is similar to __assign_str() for assiging the string, but it too takes a length argument. Note, the TRACE_EVENT() macro will allocate the location on the ring buffer to 'len + 1', that will be used to store the string into. It is a requirement that the 'len' used for this is a most the length of the string being recorded. This string can still use __get_str() just like strings created with __string() can use to retrieve the string. Link: https://lore.kernel.org/linux-nfs/20210513105018.7539996a@gandalf.local.home/ Tested-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-05-07tracing: Fix doc mistakes in trace sampleWei Yang
As the example below shows, DECLARE_EVENT_CLASS() is used instead of DEFINE_EVENT_CLASS(). Link: http://lkml.kernel.org/r/20200428214959.11259-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-03sched/core: Provide a pointer to the valid CPU maskSebastian Andrzej Siewior
In commit: 4b53a3412d66 ("sched/core: Remove the tsk_nr_cpus_allowed() wrapper") the tsk_nr_cpus_allowed() wrapper was removed. There was not much difference in !RT but in RT we used this to implement migrate_disable(). Within a migrate_disable() section the CPU mask is restricted to single CPU while the "normal" CPU mask remains untouched. As an alternative implementation Ingo suggested to use: struct task_struct { const cpumask_t *cpus_ptr; cpumask_t cpus_mask; }; with t->cpus_ptr = &t->cpus_mask; In -RT we then can switch the cpus_ptr to: t->cpus_ptr = &cpumask_of(task_cpu(p)); in a migration disabled region. The rules are simple: - Code that 'uses' ->cpus_allowed would use the pointer. - Code that 'modifies' ->cpus_allowed would use the direct mask. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190423142636.14347-1-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier for more missed filesThomas Gleixner
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15Merge branch 'for-linus' of ↵Linus Torvalds
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "The usual rocket-science from trivial tree for 4.15" * 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: MAINTAINERS: relinquish kconfig MAINTAINERS: Update my email address treewide: Fix typos in Kconfig kfifo: Fix comments init/Kconfig: Fix module signing document location misc: ibmasm: Return error on error path HID: logitech-hidpp: fix mistake in printk, "feeback" -> "feedback" MAINTAINERS: Correct path to uDraw PS3 driver tracing: Fix doc mistakes in trace sample tracing: Kconfig text fixes for CONFIG_HWLAT_TRACER MIPS: Alchemy: Remove reverted CONFIG_NETLINK_MMAP from db1xxx_defconfig mm/huge_memory.c: fixup grammar in comment lib/xz: Add fall-through comments to a switch statement
2017-11-02Merge tag 'spdx_identifiers-4.14-rc8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull initial SPDX identifiers from Greg KH: "License cleanup: add SPDX license identifiers to some files Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: License cleanup: add SPDX license identifier to uapi header files with a license License cleanup: add SPDX license identifier to uapi header files with no license License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-27Fix tracing sample code warning.Linus Torvalds
Commit 6575257c60e1 ("tracing/samples: Fix creation and deletion of simple_thread_fn creation") introduced a new warning due to using a boolean as a counter. Just make it "int". Fixes: 6575257c60e1 ("tracing/samples: Fix creation and deletion of simple_thread_fn creation") Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-17tracing/samples: Fix creation and deletion of simple_thread_fn creationSteven Rostedt (VMware)
Commit 7496946a8 ("tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()") added template examples for all the events. It created a DEFINE_EVENT_FN() example which reused the foo_bar_reg and foo_bar_unreg functions. Enabling both the TRACE_EVENT_FN() and DEFINE_EVENT_FN() example trace events caused the foo_bar_reg to be called twice, creating the test thread twice. The foo_bar_unreg would remove it only once, even if it was called multiple times, leaving a thread existing when the module is unloaded, causing an oops. Add a ref count and allow foo_bar_reg() and foo_bar_unreg() be called by multiple trace events. Cc: stable@vger.kernel.org Fixes: 7496946a8 ("tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-10-12tracing: Fix doc mistakes in trace sampleJeremy Linton
The trace sample file has a couple mispellings, lets fix them. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-03-02sched/core: Remove the tsk_cpus_allowed() wrapperIngo Molnar
So the original intention of tsk_cpus_allowed() was to 'future-proof' the field - but it's pretty ineffectual at that, because half of the code uses ->cpus_allowed directly ... Also, the wrapper makes the code longer than the original expression! So just get rid of it. This also shrinks <linux/sched.h> a bit. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-09tracing: Have the reg function allow to failSteven Rostedt (Red Hat)
Some tracepoints have a registration function that gets enabled when the tracepoint is enabled. There may be cases that the registraction function must fail (for example, can't allocate enough memory). In this case, the tracepoint should also fail to register, otherwise the user would not know why the tracepoint is not working. Cc: David Howells <dhowells@redhat.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Anton Blanchard <anton@samba.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02Sample: Trace_event: Correct the commentsChunyan Zhang
The commit 889204278ccf ("tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation") changed TRACE_SYSTEM to 'sample-trace', but didn't make the according change of its name in the comments. Link: http://lkml.kernel.org/r/1443599650-23680-1-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-17tracing: Fix sample output of dynamic arraysSteven Rostedt (Red Hat)
He Kuang noticed that the trace event samples for arrays was broken: "The output result of trace_foo_bar event in traceevent samples is wrong. This problem can be reproduced as following: (Build kernel with SAMPLE_TRACE_EVENTS=m) $ insmod trace-events-sample.ko $ echo 1 > /sys/kernel/debug/tracing/events/sample-trace/foo_bar/enable $ cat /sys/kernel/debug/tracing/trace event-sample-980 [000] .... 43.649559: foo_bar: foo hello 21 0x15 BIT1|BIT3|0x10 {0x1,0x6f6f6e53,0xff007970,0xffffffff} Snoopy ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The array length is not right, should be {0x1}. (ffffffff,ffffffff) event-sample-980 [000] .... 44.653827: foo_bar: foo hello 22 0x16 BIT2|BIT3|0x10 {0x1,0x2,0x646e6147,0x666c61,0xffffffff,0xffffffff,0x750aeffe,0x7} ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The array length is not right, should be {0x1,0x2}. Gandalf (ffffffff,ffffffff)" This was caused by an update to have __print_array()'s second parameter be the count of items in the array and not the size of the array. As there is already users of __print_array(), it can not change. But the sample code can and we can also improve on the documentation about __print_array() and __get_dynamic_array_len(). Link: http://lkml.kernel.org/r/1436839171-31527-2-git-send-email-hekuang@huawei.com Fixes: ac01ce1410fc2 ("tracing: Make ftrace_print_array_seq compute buf_len") Reported-by: He Kuang <hekuang@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-08tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()Steven Rostedt (Red Hat)
Document the use of TRACE_DEFINE_ENUM() by adding enums to the trace-event-sample.h and using this macro to convert them in the format files. Also update the comments and sho the use of __print_symbolic() and __print_flags() as well as adding comments abount __print_array(). Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-08tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentationSteven Rostedt (Red Hat)
Add documentation about TRACE_SYSTEM needing to be alpha-numeric or with underscores, and that if it is not, then the use of TRACE_SYSTEM_VAR is required to make something that is. An example of this is shown in samples/trace_events/trace-events-sample.h Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()Steven Rostedt (Red Hat)
Add to samples/trace_events/ the macros DECLARE_EVENT_CLASS() and DEFINE_EVENT() and recommend using them over multiple TRACE_EVENT() macros if the multiple events have the same format. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09tracing: Add TRACE_EVENT_FN exampleSteven Rostedt (Red Hat)
If a function should be called before a tracepoint is enabled and/or after it is disabled, the TRACE_EVENT_FN() serves this purpose. But it is not well documented. Having it as a sample would help developers to know how to use it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09tracing: Add TRACE_EVENT_CONDITION sampleSteven Rostedt (Red Hat)
The sample code lacks an example of TRACE_EVENT_CONDITION, and it has been expressed to me that this feature for TRACE_EVENT is not well known and not used when it could be. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09tracing: Update the TRACE_EVENT fields available in the sample codeSteven Rostedt (Red Hat)
The sample code in samples/trace_events/ is extremely out of date and does not show all the new fields that have been added since the sample code was written. As most people are unaware of these new fields, adding sample code and explanations of those fields should help out. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-01tracing: Change trace event sample to use strlcpy instead of strncpyZhao Hongjiang
Strings should be copied with strlcpy instead of strncpy when they will later be printed via %s. This guarantees that they terminate with a NUL '\0' character and do not run pass the end of the allocated string. This is only for sample code, but it should stil represent a good role model. Link: http://lkml.kernel.org/p/51C2E204.1080501@huawei.com Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-21tracing: Add __field_struct macro for TRACE_EVENT()Steven Rostedt
Currently the __field() macro in TRACE_EVENT is only good for primitive values, such as integers and pointers, but it fails on complex data types such as structures or unions. This is because the __field() macro determines if the variable is signed or not with the test of: (((type)(-1)) < (type)1) Unfortunately, that fails when type is a structure. Since trace events should support structures as fields a new macro is created for such a case called __field_struct() which acts exactly the same as __field() does but it does not do the signed type check and just uses a constant false for that answer. Cc: Tony Luck <tony.luck@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-15debugfs: Change debuhgfs directory of trace-events-sample.hGeunSik Lim
Default directory of debug filesystem for ftrace is /sys/kernel/debug/. Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-13tracing/events: Move TRACE_SYSTEM outside of include guardLi Zefan
If TRACE_INCLDUE_FILE is defined, <trace/events/TRACE_INCLUDE_FILE.h> will be included and compiled, otherwise it will be <trace/events/TRACE_SYSTEM.h> So TRACE_SYSTEM should be defined outside of #if proctection, just like TRACE_INCLUDE_FILE. Imaging this scenario: #include <trace/events/foo.h> -> TRACE_SYSTEM == foo ... #include <trace/events/bar.h> -> TRACE_SYSTEM == bar ... #define CREATE_TRACE_POINTS #include <trace/events/foo.h> -> TRACE_SYSTEM == bar !!! and then bar.h will be included and compiled. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A5A9CF1.2010007@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-16tracing: update sample event documentationSteven Rostedt
The comments in the sample code is a bit confusing. This patch cleans them up a little. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06tracing: update sample with TRACE_INCLUDE_FILESteven Rostedt
When creating trace events for ftrace, the header file with the TRACE_EVENT macros must also have a macro called TRACE_SYSTEM. This macro describes the name of the system the TRACE_EVENTS are defined for. It also doubles as a way for the define_trace.h file to include the file that included it. For example: in irq.h #define TRACE_SYSTEM irq [...] #include <trace/define_trace.h> The define_trace will use TRACE_SYSTEM to include irq.h. But if the name of the trace system does not match the name of the trace header file, one can override it with: Which will change define_trace.h to inclued foo_trace.h instead of foo.h The sample comments this, but people that use the sample code will more likely use the code and not read the comments. This patch changes the sample code to use the TRACE_INCLUDE_FILE to better show developers how to use it. [ Impact: make sample less confusing to developers ] Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06tracing: small trave_events sample Makefile cleanupChristoph Hellwig
Use -I$(src) to add the current directory the include path. [ Impact: cleanup ] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracing/events: don't say hi when loading the trace event sampleLi Zefan
The sample is useful for testing, and I'm using it. But after loading the module, it keeps saying hi every 10 seconds, this may be disturbing. Also Steven said commenting out the "hi" helped in causing races. :) [ Impact: make testing a bit easier ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A00F6AD.2070008@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14tracing/events: add trace-events-sampleSteven Rostedt
This patch adds a sample to the samples directory on how to create and use TRACE_EVENT trace points. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>