'\" t
.\"     Title: libtraceevent
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 01/14/2024
.\"    Manual: libtraceevent Manual
.\"    Source: libtraceevent 1.8.2
.\"  Language: English
.\"
.TH "LIBTRACEEVENT" "3" "01/14/2024" "libtraceevent 1\&.8\&.2" "libtraceevent Manual"
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.SH "NAME"
tep_get_page_size, tep_set_page_size, tep_get_sub_buffer_data_size, tep_get_sub_buffer_size \- Get / set the size of a memory page on the machine, where the trace is generated
.SH "SYNOPSIS"
.sp
.nf
\fB#include <event\-parse\&.h>\fR

int \fBtep_get_page_size\fR(struct tep_handle *\fItep\fR);
void \fBtep_set_page_size\fR(struct tep_handle *\fItep\fR, int \fIpage_size\fR);
int \fBtep_get_sub_buffer_size\fR(struct tep_handle *\fItep\fR);
int \fBtep_get_sub_buffer_data_size\fR(struct tep_handle *\fItep\fR);
int \fBtep_get_sub_buffer_commit_offset\fR(struct tep_handle *\fItep\fR);
.fi
.SH "DESCRIPTION"
.sp
The \fBtep_get_page_size()\fR function returns the size of a memory page on the machine, where the trace is generated\&. The \fItep\fR argument is trace event parser context\&.
.sp
The \fBtep_set_page_size()\fR function stores in the \fItep\fR context the size of a memory page on the machine, where the trace is generated\&. The \fItep\fR argument is trace event parser context\&. The \fIpage_size\fR argument is the size of a memory page, in bytes\&.
.sp
The \fBtep_get_sub_buffer_size()\fR returns the size of each "sub buffer" of the ring buffer\&. The Linux kernel ring buffer is broken up into sections called sub buffers\&. This returns the size of those buffers\&.
.sp
The \fBtep_get_sub_buffer_data_size()\fR returns the size of just the data portion of the sub buffers\&.
.sp
The \fBtep_get_sub_buffer_commit_offset()\fR returns the offset on the sub buffer that holds the committed portion of data\&. This number contains the index from the data portion of the sub buffer that is the end of the last element on the sub buffer\&.
.SH "RETURN VALUE"
.sp
The \fBtep_get_page_size()\fR function returns size of the memory page, in bytes\&.
.sp
The \fBtep_get_sub_buffer_size()\fR function returns the number of bytes each sub buffer is made up of\&.
.sp
The \fBtep_get_sub_buffer_commit_offset()\fR function returns the location on the sub buffer that contains the index of the last element\&.
.SH "EXAMPLE"
.sp
.if n \{\
.RS 4
.\}
.nf
#include <unistd\&.h>
#include <event\-parse\&.h>
\&.\&.\&.
struct tep_handle *tep = tep_alloc();
\&.\&.\&.
        int page_size = getpagesize();

        tep_set_page_size(tep, page_size);

        printf("The page size for this machine is %d\en", tep_get_page_size(tep));
.fi
.if n \{\
.RE
.\}
.SH "FILES"
.sp
.if n \{\
.RS 4
.\}
.nf
\fBevent\-parse\&.h\fR
        Header file to include in order to have access to the library APIs\&.
\fB\-ltraceevent\fR
        Linker switch to add when building a program that uses the library\&.
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.sp
\fBlibtraceevent\fR(3), \fBtrace\-cmd\fR(1)
.SH "AUTHOR"
.sp
.if n \{\
.RS 4
.\}
.nf
\fBSteven Rostedt\fR <\m[blue]\fBrostedt@goodmis\&.org\fR\m[]\&\s-2\u[1]\d\s+2>, author of \fBlibtraceevent\fR\&.
\fBTzvetomir Stoyanov\fR <\m[blue]\fBtz\&.stoyanov@gmail\&.com\fR\m[]\&\s-2\u[2]\d\s+2>, author of this man page\&.
.fi
.if n \{\
.RE
.\}
.SH "REPORTING BUGS"
.sp
Report bugs to <\m[blue]\fBlinux\-trace\-devel@vger\&.kernel\&.org\fR\m[]\&\s-2\u[3]\d\s+2>
.SH "LICENSE"
.sp
libtraceevent is Free Software licensed under the GNU LGPL 2\&.1
.SH "RESOURCES"
.sp
\m[blue]\fBhttps://git\&.kernel\&.org/pub/scm/libs/libtrace/libtraceevent\&.git/\fR\m[]
.SH "NOTES"
.IP " 1." 4
rostedt@goodmis.org
.RS 4
\%mailto:rostedt@goodmis.org
.RE
.IP " 2." 4
tz.stoyanov@gmail.com
.RS 4
\%mailto:tz.stoyanov@gmail.com
.RE
.IP " 3." 4
linux-trace-devel@vger.kernel.org
.RS 4
\%mailto:linux-trace-devel@vger.kernel.org
.RE