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2017-08-15simpletrace: fix flight recorder --no-header optionStefan Hajnoczi
The simpletrace.py script can pretty-print flight recorder ring buffers. These are not full simpletrace binary trace files but just the end of a trace file. There is no header and the event ID mapping information is often unavailable since the ring buffer may have filled up and discarded event ID mapping records. The simpletrace.stp script that generates ring buffer traces uses the same trace-events-all input file as simpletrace.py. Therefore both scripts have the same global ordering of trace events. A dynamic event ID mapping isn't necessary: just use the trace-events-all file as the reference for how event IDs are numbered. It is now possible to analyze simpletrace.stp ring buffers again using: $ ./simpletrace.py trace-events-all path/to/ring-buffer Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170815084430.7128-3-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-07-31docs: fix broken paths to docs/devel/tracing.txtPhilippe Mathieu-Daudé
With the move of some docs/ to docs/devel/ on ac06724a71, no references were updated. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-06-07simpletrace: Improve the error message if event is not declaredJose Ricardo Ziviani
Today, if we use a trace-event file which does not declare an event existing in the log file we'll get the following error: $ scripts/simpletrace.py trace-events trace-68508 Traceback (most recent call last): File "scripts/simpletrace.py", line 242, in <module> run(Formatter()) File "scripts/simpletrace.py", line 217, in run process(events, sys.argv[2], analyzer, read_header=read_header) File "scripts/simpletrace.py", line 192, in process for rec in read_trace_records(edict, log): File "scripts/simpletrace.py", line 107, in read_trace_records rec = read_record(edict, idtoname, fobj) File "scripts/simpletrace.py", line 71, in read_record return get_record(edict, idtoname, rechdr, fobj) File "scripts/simpletrace.py", line 45, in get_record event = edict[name] KeyError: 'qemu_mutex_locked' This patch improves this error by adding a hint instead of just that KeyError log: $ scripts/simpletrace.py trace-events trace-68508 'qemu_mutex_locked' event is logged but is not declared in the trace events file, try using trace-events-all instead. Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 1496075404-8845-1-git-send-email-joserz@linux.vnet.ibm.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-04-21simpletrace: document Analyzer method signaturesStefan Hajnoczi
Users can inherit from the simpletrace.Analyzer class and receive callbacks when events of interest occur in a trace file. The method signature is a little magic because the timestamp and pid arguments are optional. Document this. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 20170411095654.18383-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-31trace: improve error reporting when parsing simpletrace headerDaniel P. Berrange
When loading a simpletrace binary file we just report "Not a valid trace file!" which is not very helpful. Report exactly which field we found to be invalid. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170125161417.31949-9-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: rename _read_events to read_eventsDaniel P. Berrange
The _read_events method is used by callers outside of its module, so should be a public method, not private. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-18-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: emit name <-> ID mapping in simpletrace headerDaniel P. Berrange
Currently simpletrace assumes that events are given IDs starting from 0, based on the order in which they appear in the trace-events file, with no gaps. When the trace-events file is split up, this assumption becomes problematic. To deal with this, extend the simpletrace format so that it outputs a table of event name <-> ID mappings. That will allow QEMU to assign arbitrary IDs to events without breaking simpletrace parsing. The v3 simple trace format was FILE HEADER EVENT TRACE RECORD 0 EVENT TRACE RECORD 1 ... EVENT TRACE RECORD N The v4 simple trace format is now FILE HEADER EVENT MAPPING RECORD 0 EVENT MAPPING RECORD 1 ... EVENT MAPPING RECORD M EVENT TRACE RECORD RECORD 0 EVENT TRACE RECORD RECORD 1 ... EVENT TRACE RECORD N Although this shows all the mapping records being emitted upfront, this is not required by the format. While the main simpletrace backend will emit all mappings at startup, the systemtap simpletrace.stp script will emit the mappings at first use. eg FILE HEADER ... EVENT MAPPING RECORD 0 EVENT TRACE RECORD RECORD 0 EVENT TRACE RECORD RECORD 1 EVENT MAPPING RECORD 1 EVENT TRACE RECORD RECORD 2 ... EVENT TRACE RECORD N This is more space efficient given that most trace records only include a subset of events. In modifying the systemtap simpletrace code, a 'begin' probe was added to emit the trace event header, so you no longer need to add '--no-header' when running simpletrace.py for systemtap generated trace files. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-12-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-12simpletrace: add simpletrace.py --no-header optionStefan Hajnoczi
It can be useful to read simpletrace files that have no header. For example, a ring buffer may not have a header record but can still be processed if the user is sure the file format version is compatible. $ scripts/simpletrace.py --no-header trace-events trace-file Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09simpletrace: add support for trace record pid fieldStefan Hajnoczi
Extract the pid field from the trace record and print it. Change the trace record tuple from: (event_num, timestamp, arg1, ..., arg6) to: (event_num, timestamp, pid, arg1, ..., arg6) Trace event methods now support 3 prototypes: 1. <event-name>(arg1, arg2, arg3) 2. <event-name>(timestamp, arg1, arg2, arg3) 3. <event-name>(timestamp, pid, arg1, arg2, arg3) Existing script continue to work without changes, they only know about prototypes 1 and 2. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-07trace: [tracetool] Minimize the amount of per-backend codeLluís Vilanova
Backends now only contain the essential backend-specific code, and most of the work is moved to frontend code. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-07trace: [simple] Bump up log version numberLluís Vilanova
The following tracetool cleanup changes the event numbering policy. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-08-15trace: Fix "Qemu" -> "QEMU"Stefan Weil
Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-19Update simpletrace.py for new log formatHarsh Prateek Bora
Support new tracelog format for multiple arguments and strings. Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-09-01simpletrace: fix process() argument countStefan Hajnoczi
The simpletrace.process() function invokes analyzer methods with the wrong number of arguments if a timestamp should be included. This patch fixes the issue so that trace analysis scripts can make use of timestamps. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-03-07simpletrace: Thread-safe tracingStefan Hajnoczi
Trace events outside the global mutex cannot be used with the simple trace backend since it is not thread-safe. There is no check to prevent them being enabled so people sometimes learn this the hard way. This patch restructures the simple trace backend with a ring buffer suitable for multiple concurrent writers. A writeout thread empties the trace buffer when threshold fill levels are reached. Should the writeout thread be unable to keep up with trace generation, records will simply be dropped. Each time events are dropped a special record is written to the trace file indicating how many events were dropped. The event ID is 0xfffffffffffffffe and its signature is dropped(uint32_t count). Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-03-06simpletrace: Make simpletrace.py a Python moduleStefan Hajnoczi
The simpletrace.py script pretty-prints a binary trace file. Most of the code can be reused by trace file analysis scripts, so turn it into a module. Here is an example script that uses the new simpletrace module: #!/usr/bin/env python # Print virtqueue elements that were never returned to the guest. import simpletrace class VirtqueueRequestTracker(simpletrace.Analyzer): def __init__(self): self.elems = set() def virtqueue_pop(self, vq, elem, in_num, out_num): self.elems.add(elem) def virtqueue_fill(self, vq, elem, length, idx): self.elems.remove(elem) def end(self): for elem in self.elems: print hex(elem) simpletrace.run(VirtqueueRequestTracker()) The simpletrace API is based around the Analyzer class. Users implement an analyzer subclass and add methods for trace events they want to process. A catchall() method is invoked for trace events which do not have dedicated methods. Finally, there are also begin() and end() methods like in sed that can be used to perform setup or print statistics at the end. A binary trace file is processed either with: simpletrace.run(analyzer) # uses command-line args or with: simpletrace.process('path/to/trace-events', 'path/to/trace-file', analyzer) Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-20Add scripts directoryBlue Swirl
Move build and user scripts into scripts directory. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>