1 /* Copyright (c) 2003-2004 Roger Seguin <roger_seguin@msn.com>
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License as published by
5  * the Free Software Foundation; either version 2 of the License, or
6  * (at your option) any later version.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU Library General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
16  */
17 #ifndef _devperf_h
18 #define _devperf_h
19 
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23 
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <inttypes.h>
27 
28 
29 enum {
30     NO_ERROR,
31     NO_EXTENDED_STATS
32 };
33 
34 
35 typedef struct devperf_t {
36     uint64_t        timestamp_ns;
37     uint64_t        rbytes;	/* Number of bytes read from the device */
38     uint64_t        wbytes;	/* Number of bytes written to the device */
39     uint64_t        rbusy_ns;	/* Device read busy time */
40     uint64_t        wbusy_ns;	/* Device write busy time */
41     int32_t         qlen;	/* Current queue length */
42 } devperf_t;
43 
44 
45 #ifdef __cplusplus
46 extern          "C" {
47 #endif
48 
49     int             DevPerfInit (void);
50     /* Make required initialisations */
51     /* Return 0 on success */
52 
53     int             DevCheckStatAvailability (char const **StatisticsFile);
54     /* Check the availability of required kernel statistics */
55     /* Get the statistics file name */
56     /* Return 0 on success */
57 
58     int             DevGetPerfData (const void *devid,
59 				    struct devperf_t *perf);
60     /* Get disk performance data stored by the kernel */
61     /* Return 0 on success, -1 otherwise */
62 
63 #ifdef __cplusplus
64 }				/* extern "C" */
65 #endif
66 
67 #endif				/* _devperf_h */
68