Commit-ID: c76c22421875bbcbadd3c9fd4033981677aacfb0 Gitweb: https://git.kernel.org/tip/c76c22421875bbcbadd3c9fd4033981677aacfb0 Author: Tzvetomir Stoyanov <tstoya...@vmware.com> AuthorDate: Fri, 10 May 2019 15:56:20 -0400 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Wed, 15 May 2019 16:36:48 -0300
tools lib traceevent: Man page for tep_read_number() Create man page for tep_read_number() libtraceevent API. Signed-off-by: Tzvetomir Stoyanov <tstoya...@vmware.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Jiri Olsa <jo...@redhat.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: linux-trace-de...@vger.kernel.org Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-14-tstoya...@vmware.com Link: http://lkml.kernel.org/r/20190510200108.042164...@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- ...vent-cpus.txt => libtraceevent-endian_read.txt} | 29 +++++++++++----------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/tools/lib/traceevent/Documentation/libtraceevent-cpus.txt b/tools/lib/traceevent/Documentation/libtraceevent-endian_read.txt similarity index 54% copy from tools/lib/traceevent/Documentation/libtraceevent-cpus.txt copy to tools/lib/traceevent/Documentation/libtraceevent-endian_read.txt index 5ad70e43b752..e64851b6e189 100644 --- a/tools/lib/traceevent/Documentation/libtraceevent-cpus.txt +++ b/tools/lib/traceevent/Documentation/libtraceevent-endian_read.txt @@ -3,8 +3,7 @@ libtraceevent(3) NAME ---- -tep_get_cpus, tep_set_cpus - Get / set the number of CPUs, which have a tracing -buffer representing it. Note, the buffer may be empty. +tep_read_number - Reads a number from raw data. SYNOPSIS -------- @@ -12,23 +11,20 @@ SYNOPSIS -- *#include <event-parse.h>* -int *tep_get_cpus*(struct tep_handle pass:[*]_tep_); -void *tep_set_cpus*(struct tep_handle pass:[*]_tep_, int _cpus_); +unsigned long long *tep_read_number*(struct tep_handle pass:[*]_tep_, const void pass:[*]_ptr_, int _size_); -- DESCRIPTION ----------- -The _tep_get_cpus()_ function gets the number of CPUs, which have a tracing -buffer representing it. The _tep_ argument is trace event parser context. - -The _tep_set_cpus()_ function sets the number of CPUs, which have a tracing -buffer representing it. The _tep_ argument is trace event parser context. -The _cpu_ argument is the number of CPUs with tracing data. +The _tep_read_number()_ function reads an integer from raw data, taking into +account the endianness of the raw data and the current host. The _tep_ argument +is the trace event parser context. The _ptr_ is a pointer to the raw data, where +the integer is, and the _size_ is the size of the integer. RETURN VALUE ------------ -The _tep_get_cpus()_ functions returns the number of CPUs, which have tracing -data recorded. +The _tep_read_number()_ function returns the integer in the byte order of +the current host. In case of an error, 0 is returned. EXAMPLE ------- @@ -38,9 +34,14 @@ EXAMPLE ... struct tep_handle *tep = tep_alloc(); ... - tep_set_cpus(tep, 5); +void process_record(struct tep_record *record) +{ + int offset = 24; + int data = tep_read_number(tep, record->data + offset, 4); + + /* Read the 4 bytes at the offset 24 of data as an integer */ +} ... - printf("We have tracing data for %d CPUs", tep_get_cpus(tep)); -- FILES
