aeb802f872
When it processes AUXTRACE_INFO, it calls to auxtrace_queue_data() to
collect AUXTRACE data first. That won't work with pipe since it needs
lseek() to read the scattered aux data.
$ perf record -o- -e intel_pt// true | perf report -i- --itrace=i100
# To display the perf.data header info, please use --header/--header-only options.
#
0x4118 [0xa0]: failed to process type: 70
Error:
failed to process sample
For the pipe mode, it can handle the aux data as it gets. But there's
no guarantee it can get the aux data in time. So the following warning
will be shown at the beginning:
WARNING: Intel PT with pipe mode is not recommended.
The output cannot relied upon. In particular,
time stamps and the order of events may be incorrect.
Fixes: dbd134322e74f19d ("perf intel-pt: Add support for decoding AUX area samples")
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230131023350.1903992-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.