Commit Graph

5 Commits

Author SHA1 Message Date
Yaowei Bai db817b8c50 tracing: Use double-dash spelling for trace option
The '-trace' and '--trace' spellings are only both supported in qemu
binary, while for qemu-nbd or qemu-img only '--trace' spelling is
supported. So for the consistency of trace option invocation, we
should use double-dash spelling in our documentation.

This's also mentioned in
https://wiki.qemu.org/BiteSizedTasks#Consistent_option_usage_in_documentation
.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1530674247-31200-1-git-send-email-baiyaowei@cmss.chinamobile.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-07-19 13:09:04 +01:00
Stefan Hajnoczi ec09f87753 trace: forbid floating point types
Only one existing trace event uses a floating point type.  Unfortunately
float and double cannot be supported since SystemTap does not have
floating point types.

Remove float and double from the whitelist and document this limitation.
Update the migrate_transferred trace event to use uint64_t instead of
double.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-id: 20180621150254.4922-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-27 11:09:29 +01:00
Stefan Hajnoczi d87aa13803 trace: add trace_event_get_state_backends()
Code that checks dstate is unaware of SystemTap and LTTng UST dstate, so
the following trace event will not fire when solely enabled by SystemTap
or LTTng UST:

  if (trace_event_get_state(TRACE_MY_EVENT)) {
      str = g_strdup_printf("Expensive string to generate ...",
                            ...);
      trace_my_event(str);
      g_free(str);
  }

Add trace_event_get_state_backends() to fetch backend dstate.  Those
backends that use QEMU dstate fetch it as part of
generate_h_backend_dstate().

Update existing trace_event_get_state() callers to use
trace_event_get_state_backends() instead.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170731140718.22010-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-08-01 12:13:07 +01:00
Stefan Hajnoczi 304187c51c trace: update old trace events in docs
Commit c5f1ad429c ("block: Remove
bdrv_aio_readv/writev/flush()") removed
bdrv_aio_readv()/bdrv_aio_writev() so the example in the tracing
documentation is no longer valid.

Reported-by: Wang Dong <dongdwdw@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170714133111.27359-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-07-17 13:11:13 +01:00
Paolo Bonzini ac06724a71 docs: create config/, devel/ and spin/ subdirectories
Developer documentation should be its own manual.  As a start, move all
developer-oriented files to a separate directory.

Also move non-text files to their own directories: docs/config/ for
QEMU -readconfig input, and docs/spin/ for formal models to be used
with the SPIN model checker.

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-07 18:22:03 +02:00