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2011-04-26docs/tracing.txt: minor documentation fixesLluís
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-04-26docs: Trace events must not expect pointer dereferencingStefan Hajnoczi
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>
2011-03-06docs: Update stderr and simple backend, add systemtap backendStefan Hajnoczi
The following additions to the tracing documentation are included: 1. Move "stderr" backend documentation to top-level and out of "simple" backend. Include hints on when this backend is useful. 2. Document the "simple" backend thread-safety limitation. 3. Document the "dtrace" backend for SystemTap. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-29New trace-event backend: stderrFabien Chouteau
This backend sends trace events to standard error output during the emulation. Also add a "--list-backends" option to tracetool, so configure script can display the list of available backends. Signed-off-by: Fabien Chouteau <chouteau@adacore.com> Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-10-20trace: Format strings must begin/end with double quotesStefan Hajnoczi
Document the restriction that format strings must begin and end with double quotes. This is for easy parsing since we don't run cpp over trace-events. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-10-09trace: Use portable format stringsStefan Hajnoczi
It is not portable to use "%ld" for int64_t because int64_t may have type long on 64-bit platforms and long long on 32-bit platforms. Use the standard library PRId64 macros to keep format strings portable. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-09-09trace: Add user documentationStefan Hajnoczi
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>