The proc provider include probes pertaining to the following activities: process creation and termination, LWP creation and termination, executing new program images, and sending and handling signals.
The proc probes are described in the following table.
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The argument types for the proc probes are listed in Figure 48, Table 48, List of proc Probe Arguments. The arguments are described in Figure 47, Table 47, List of proc Probes.
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Several proc probes have arguments of type lwpsinfo_t. The definition of the lwpsinfo_t structure as available to DTrace consumers is as follows:
typedef struct lwpsinfo {
int pr_flag; /* flags; see below */
id_t pr_lwpid; /* LWP id */
uintptr_t pr_addr; /* internal address of thread */
uintptr_t pr_wchan; /* wait addr for sleeping thread */
char pr_stype; /* synchronization event type */
char pr_state; /* numeric thread state */
char pr_sname; /* printable character for pr_state */
char pr_nice; /* nice for cpu usage */
short pr_syscall; /* system call number (if in syscall) */
int pr_pri; /* priority, high value = high priority */
char pr_clname[PRCLSZ]; /* scheduling class name */
processorid_t pr_onpro; /* processor which last ran this thread */
processorid_t pr_bindpro; /* processor to which thread is bound */
psetid_t pr_bindpset; /* processor set to which thread is bound */
} lwpsinfo_t;
The pr_flag field is a bit-mask holding flags describing the process. These flags and their meanings are described in Figure 49, Table 49, proce pr_flag Values.
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The pr_addr field is the address of a private, in-kernel data structure representing the thread. While the data structure is private, the pr_addr field may be used as a token unique to a thread for the thread's lifetime.
The pr_wchan field is set when the thread is sleeping on a synchronization object. The meaning of the pr_wchan field is private to the kernel implementation, but the field may be used as a token unique to the synchronization object.
The pr_stype field is set when the thread is sleeping on a synchronization object. The possible values for the pr_stype field are in Figure 50, Table 50, proc pr_stype Values.
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The pr_state field is set to one of the values in Figure 51, Table 51, proc pr_state Values. The pr_sname field is set to a corresponding character shown in parentheses in the same table.
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Several proc probes have an argument of type psinfo_t, a structure that is documented in proc. The definition of the psinfo_t structure as available to DTrace consumers is as follows:
typedef struct psinfo {
int pr_nlwp; /* number of active lwps in the process */
pid_t pr_pid; /* unique process id */
pid_t pr_ppid; /* process id of parent */
pid_t pr_pgid; /* pid of process group leader */
pid_t pr_sid; /* session id */
uid_t pr_uid; /* real user id */
uid_t pr_euid; /* effective user id */
gid_t pr_gid; /* real group id */
gid_t pr_egid; /* effective group id */
uintptr_t pr_addr; /* address of process */
dev_t pr_ttydev; /* controlling tty device (or PRNODEV) */
timestruc_t pr_start; /* process start time, from the epoch */
char pr_fname[PRFNSZ]; /* name of execed file */
char pr_psargs[PRARGSZ]; /* initial characters of arg list */
int pr_argc; /* initial argument count */
uintptr_t pr_argv; /* address of initial argument vector */
uintptr_t pr_envp; /* address of initial environment vector */
char pr_dmodel; /* data model of the process */
taskid_t pr_taskid; /* task id */
projid_t pr_projid; /* project id */
poolid_t pr_poolid; /* pool id */
zoneid_t pr_zoneid; /* zone id */
} psinfo_t;
The pr_dmodel field is set to either PR_MODEL_ILP32, denoting a 32-bit process, or PR_MODEL_LP64, denoting a 64-bit process.
You can use the exec probe to determine which programs are being executed, and by whom, as shown in the following example:
#pragma D option quiet
proc:::exec
{
self->parent = execname;
}
proc:::exec-success
/self->parent != NULL/
{
@[self->parent, execname] = count();
self->parent = NULL;
}
proc:::exec-failure
/self->parent != NULL/
{
self->parent = NULL;
}
END
{
printf("%-20s %-20s %s\n", "WHO", "WHAT", "COUNT");
printa("%-20s %-20s %@d\n", @);
}
Running the example script for a short period of time on a build machine results in output similar to the following example:
# dtrace -s ./whoexec.d ^C WHO WHAT COUNT make.bin yacc 1 tcsh make 1 make.bin spec2map 1 sh grep 1 lint lint2 1 sh lint 1 sh ln 1 cc ld 1 make.bin cc 1 lint lint1 1 sh lex 1 make.bin mv 2 sh sh 3 sh make 3 sh sed 4 sh tr 4 make make.bin 4 sh install.bin 5 sh rm 6 cc ir2hf 33 cc ube 33 sh date 34 sh mcs 34 cc acomp 34 sh cc 34 sh basename 34 basename expr 34 make.bin sh 87
If you want to know how long programs are running from creation to termination, you can enable the start and exit probes, as shown in the following example:
proc:::start
{
self->start = timestamp;
}
proc:::exit
/self->start/
{
@[execname] = quantize(timestamp - self->start);
self->start = 0;
}
Running the example script on the build server for several seconds results in output similar to the following example:
# dtrace -s ./progtime.d
dtrace: script './progtime.d' matched 2 probes
^C
ir2hf
value ------------- Distribution ------------- count
4194304 | 0
8388608 |@ 1
16777216 |@@@@@@@@@@@@@@@@ 14
33554432 |@@@@@@@@@@ 9
67108864 |@@@ 3
134217728 |@ 1
268435456 |@@@@ 4
536870912 |@ 1
1073741824 | 0
ube
value ------------- Distribution ------------- count
16777216 | 0
33554432 |@@@@@@@ 6
67108864 |@@@ 3
134217728 |@@ 2
268435456 |@@@@ 4
536870912 |@@@@@@@@@@@@ 10
1073741824 |@@@@@@@ 6
2147483648 |@@ 2
4294967296 | 0
acomp
value ------------- Distribution ------------- count
8388608 | 0
16777216 |@@ 2
33554432 | 0
67108864 |@ 1
134217728 |@@@ 3
268435456 | 0
536870912 |@@@@@ 5
1073741824 |@@@@@@@@@@@@@@@@@@@@@@@@@ 22
2147483648 |@ 1
4294967296 | 0
cc
value ------------- Distribution ------------- count
33554432 | 0
67108864 |@@@ 3
134217728 |@ 1
268435456 | 0
536870912 |@@@@ 4
1073741824 |@@@@@@@@@@@@@@ 13
2147483648 |@@@@@@@@@@@@ 11
4294967296 |@@@ 3
8589934592 | 0
sh
value ------------- Distribution ------------- count
262144 | 0
524288 |@ 5
1048576 |@@@@@@@ 29
2097152 | 0
4194304 | 0
8388608 |@@@ 12
16777216 |@@ 9
33554432 |@@ 9
67108864 |@@ 8
134217728 |@ 7
268435456 |@@@@@ 20
536870912 |@@@@@@ 26
1073741824 |@@@ 14
2147483648 |@@ 11
4294967296 | 3
8589934592 | 1
17179869184 | 0
make.bin
value ------------- Distribution ------------- count
16777216 | 0
33554432 |@ 1
67108864 |@ 1
134217728 |@@ 2
268435456 | 0
536870912 |@@ 2
1073741824 |@@@@@@@@@ 9
2147483648 |@@@@@@@@@@@@@@@ 14
4294967296 |@@@@@@ 6
8589934592 |@@ 2
17179869184 | 0
Instead of knowing the amount of time that a particular process takes to run, you might want to know how long individual threads take to run. The following example shows how to use the lwp-start and lwp-exit probes for this purpose:
proc:::lwp-start
/tid != 1/
{
self->start = timestamp;
}
proc:::lwp-exit
/self->start/
{
@[execname] = quantize(timestamp - self->start);
self->start = 0;
}
Running the example script on an NFS and calendar server results in output similar to the following example:
# dtrace -s ./lwptime.d
dtrace: script './lwptime.d' matched 3 probes
^C
nscd
value ------------- Distribution ------------- count
131072 | 0
262144 |@ 18
524288 |@@ 24
1048576 |@@@@@@@ 75
2097152 |@@@@@@@@@@@@@@@@@@@@@@@ 245
4194304 |@@ 22
8388608 |@@ 24
16777216 | 6
33554432 | 3
67108864 | 1
134217728 | 1
268435456 | 0
mountd
value ------------- Distribution ------------- count
524288 | 0
1048576 |@ 15
2097152 |@ 24
4194304 |@@@ 51
8388608 |@ 17
16777216 |@ 24
33554432 |@ 15
67108864 |@@@@ 57
134217728 |@ 28
268435456 |@ 26
536870912 |@@ 39
1073741824 |@@@ 45
2147483648 |@@@@@ 72
4294967296 |@@@@@ 77
8589934592 |@@@ 55
17179869184 | 14
34359738368 | 2
68719476736 | 0
automountd
value ------------- Distribution ------------- count
1048576 | 0
2097152 | 3
4194304 |@@@@ 146
8388608 | 6
16777216 | 6
33554432 | 9
67108864 |@@@@@ 203
134217728 |@@ 87
268435456 |@@@@@@@@@@@@@@@ 534
536870912 |@@@@@@ 223
1073741824 |@ 45
2147483648 | 20
4294967296 | 26
8589934592 | 20
17179869184 | 19
34359738368 | 7
68719476736 | 2
137438953472 | 0
iCald
value ------------- Distribution ------------- count
8388608 | 0
16777216 |@@@@@@@ 20
33554432 |@@@ 9
67108864 |@@ 8
134217728 |@@@@@ 16
268435456 |@@@@ 11
536870912 |@@@@ 11
1073741824 |@ 4
2147483648 | 2
4294967296 | 0
8589934592 |@@ 8
17179869184 |@ 5
34359738368 |@ 4
68719476736 |@@ 6
137438953472 |@ 4
274877906944 | 2
549755813888 | 0
You can use the signal-send probe to determine the sending and receiving process associated with any signal, as shown in the following example:
#pragma D option quiet
proc:::signal-send
{
@[execname, stringof(args[1]->pr_fname), args[2]] = count();
}
END
{
printf("%20s %20s %12s %s\n",
"SENDER", "RECIPIENT", "SIG", "COUNT");
printa("%20s %20s %12d %@d\n", @);
}
Running this script results in output similar to the following example:
# dtrace -s ./sig.d
^C
SENDER RECIPIENT SIG COUNT
xterm dtrace 2 1
xterm soffice.bin 2 1
tr init 18 1
sched test 18 1
sched fvwm2 18 1
bash bash 20 1
sed init 18 2
sched ksh 18 15
sched Xsun 22 471
The proc provider uses DTrace's stability mechanism to describe its stabilities, as shown in the following table. For more information about the stability mechanism, see DTrace Stability Mechanisms.
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