info on kstat please
I am trying to use the kernal statistics interface
kstat for a mini-performance montoring suite.
Can anyone direct me to some more detailed information
and, if possible some worked examples ?#
I have seen the example code on the Solaris 2 Competitive Migration
Program
http://www.sun.com/smcc/solaris-migration/docs/courses/sysadminHTML/kernel.html but this seems to be out of date.
In particular I can't figure out just how the kstat_named structure works,
and how you find out what names to use.
[560 byte] By [
fulmar] at [2007-11-14]
Fulmar,
check out enclosed tutorials.
I hope this helps.
Regards
Georg Edelmann
Sun Microsystems Ltd.
--
SYNOPSIS:A tutorial for kstat, the Solaris kernel statistics facility
OS: Solaris/SunOS
PLATFORM:Generic
OS VERSION: 7
TECH AREA:OS
PRODUCT:Kernel
KEYWORDS:kstat kernel statistic
DESCRIPTION:
The following is intended as a hands-on introduction to the Solaris
kernel statistic facility - kstat. Use this as a tutorial. The included
sample programs are fully functional.
SOLUTION:
NOTE : Before you start, make sure you read and understood kstat(3K) and
kstat(9S).
Introduction
kstat facility is a general-purpose mechanism for providing kernel
statistics to userland applications. Whenever a developer needs to gather
statistical data within the kernel and requires these data to be passed on
to an application, kstats are the solution.
The current Solaris implementation makes heavy use of kstat. Multiple
applications are used to read these statistics, including sar(1), netstat(1M),
nfsstat(1M), etc.
The following is a simple example to illustrate the use of kstat. It contains
two major components : the kernel module to generate a kstat
"kstat_drv", and
the application to read this kstat "kstat_app". Both are explained in
detail in
the following sections.
The kernel module "kstat_drv"
--
9
10 static struct modlmisc modlmisc = {
11 &mod_miscops, "A kernel statistics (kstat) example"
12 };
13
14 static struct modlinkage modlinkage = {
15 MODREV_1, (void *)&modlmisc, NULL
16 };
"modlmisc" and "modlinkage" define "kstat_drv" as a
kernel loadable module
of type "misc". This will allow us to use modload(1M)/modunload(1M) to
load/unload the module.
17
18 char *message= "A simple kstat example";
19
That's the kernel statistic we will export to the application. As you can
see there's no structure imposed on it, ie. it's what kstat refers to as
KSTAT_TYPE_RAW - a sequence of bytes.
24
25 ksp = kstat_create("kstat_drv", 0,
"kstat_list", "misc",
26KSTAT_TYPE_RAW, 1, KSTAT_FLAG_WRITABLE);
This is where it gets interesting. This call to kstat_create(9F) creates
a kernel statistic with the following characteristics :
provider's module : kstat_drv
instance : 0
kstat identifier : kstat_list
or name
class : misc
As mentioned, the string of byte in "message" is of kstat type
KSTAT_TYPE_RAW.
This kstat_create() initializes a kstat(9S) structure, allocates memory
for the entire kstat (header and data), initializes all header fields,
initializes the data section to all zeroes, assigns a unique kstat ID (KID)
and puts the kstat onto the system's kstat chain. The returned kstat in
"ksp" is still marked invalid because then we have not initialized the
data section.
27
28 if (ksp != NULL) {
29ksp->ks_data_size = strlen(message);
30ksp->ks_data = message;
31ksp->ks_lock = NULL;
32
33kstat_install(ksp);
34 }
35
Before we install the kstat with kstat_install(9F), we need to copy the
data into the data section of the kstat. This is what happens in line
29 and 30.
If you initialize the lock to NULL as in line 31, a kstat_read(3K) will
not try to acquire a mutex when reading the kstat.
38
39 int _fini(void)
40 {
41 kstat_delete(ksp);
42 return (mod_remove(&modlinkage));
43 }
kstat_delete(9F) cleans up the kstat, that is whenever you unload this module
kstat_delete() removes ksp from the kstat chain and frees all associated
system resources.
The application "kstat_app"
"kstat_app" reads
Fulmar,
check out enclosed tutorials. This time hopefully properly formatted.
I hope this helps.
Regards
Georg Edelmann
Sun Microsystems Ltd.
-
<pre>
DOCUMENT ID: 2486-02
SYNOPSIS:How to get a list of all kstat types currently supported in the
system
OS: Solaris/SunOS
PLATFORM:Generic
OS VERSION: 2.6
TECH AREA:OS
PRODUCT:Libraries
KEYWORDS:kstat kstat_read kstat_types
DESCRIPTION:
kstat - kernel statistics facility - defines various kstat data types. How can
I find out which are the ones defined on my system ?
SOLUTION:
To get a list of all kstat types currently supported in the system, tools can
read out the
standard system kstat kstat_types (full name spec is <"unix", 0,
"kstat_types">
). This is
a KSTAT_TYPE_NAMED kstat in which the name field describes the type of kstat,
and the value
field is the kstat type number.
Here's an example program :
#include <stdio.h>
#include <kstat.h>
main()
{
kstat_ctl_t*kc;
kstat_t *ksp;
kstat_named_t*kstat_named;
int i=0;
if ((kc = kstat_open()) == NULL)
{
perror("kstat_open failed"); exit(1);
}
if ((ksp = kstat_lookup(kc, "unix", 0, "kstat_types"))
== NULL)
{
perror("kstat_lookup failed"); exit(1);
}
if (kstat_read(kc, ksp, NULL) < 0)
{
perror("kstat_read failed"); exit(1);
}
kstat_named = ksp->ks_data;
printf("List of all kstat types currently supported : ");
for(i=0; i<ksp->ks_ndata; i++)
{
printf("%s ", kstat_named.name);
}
printf("\n");
}
-
DOCUMENT ID: 2639-99
SYNOPSIS:A tutorial for kstat, the Solaris kernel statistics facility
OS: Solaris/SunOS
PLATFORM:Generic
OS VERSION: 7
TECH AREA:OS
PRODUCT:Kernel
KEYWORDS:kstat kernel statistic
DESCRIPTION:
The following is intended as a hands-on introduction to the Solaris
kernel statistic facility - kstat. Use this as a tutorial. The included
sample programs are fully functional.
SOLUTION:
NOTE : Before you start, make sure you read and understood kstat(3K) and
kstat(9S).
Introduction
kstat facility is a general-purpose mechanism for providing kernel
statistics to userland applications. Whenever a developer needs to gather
statistical data within the kernel and requires these data to be passed on
to an application, kstats are the solution.
The current Solaris implementation makes heavy use of kstat. Multiple
applications are used to read these statistics, including sar(1), netstat(1M),
nfsstat(1M), etc.
The following is a simple example to illustrate the use of kstat. It contains
two major components : the kernel module to generate a kstat
"kstat_drv", and
the application to read this kstat "kstat_app". Both are explained in
detail in
the following sections.
The kernel module "kstat_drv"
--
9
10 static struct modlmisc modlmisc = {
11 &mod_miscops, "A kernel statistics (kstat) example"
12 };
13
14 static struct modlinkage modlinkage = {
15 MODREV_1, (void *)&modlmisc, NULL
16 };
"modlmisc" and "modlinkage" define "kstat_drv" as a
kernel loadable module
of type "misc". This will allow us to use modload(1M)/modunload(1M) to
load/unload the module.
17
18 char *message= "A simple kstat example";
19
That's the kernel statistic we will export to the application. As you can
see there's no structure imposed on it, ie. it's what kstat refers to as
KSTAT_TYPE_RAW - a sequence of byte
