TDUMP(8) BSD System Manager's Manual TDUMP(8)NAMEtdump - Dump kernel trace buffer
SYNOPSIStdump [-M core] [-N system] [-v] [-n]
DESCRIPTION
The tdump utility extracts the entries from the in kernel wrap around
trace buffers, merge sorts the entries by time, and formats a display
based on the data.
The trace entries are displayed newest first, oldest last.
The fields in each trace entry are:
C The cpu number making the trace entry (a hex digit from 0
through f).
Idx The index (entry number) in the respective CPU's trace buffer
(in hex).
Delta-T Number of CPU clocks between this entry (older) and the entry
above it (newer). The time span of a clock cycle depends on
the speed of the CPU, for Intel Pentium systems one can use
the rated internal clock speed (a Pentium-233/MMX would per-
form 1 clock per 1/233000000 seconds (~4.29 nS)).
Trace data The trace data takes up the remainder of the line, this may
be almost any output that can be generated via a printf
statement with up to 5 arguments.
In verbose mode the full 64 bit time stamp and the time from the start of
the trace are also printed; in addition the 5 possible arguments (rele-
vant or not) are printed in hex as well as decoded in the normal printf()
format.
When the delta-T is a large negative number (0xffff....) this usually in-
dicates that the trace buffer wrapped around while the trace dump was be-
ing taken (this can happen when running tdump from a running system or
via an ICE probe).
The options are:
-M core Specifies physical memory image; this could be a core dump
or /dev/mem (to access live system memory). Default:
/dev/mem
-M system Specifies location of kernel executable used to extract sym-
bol tables. This kernel must be the kernel that corresponds
to the physical memory image being debugged. Default: /bsd
-v Verbose (but fairly cluttered) display.
-n Do not cache strings locally (read from image each time).
Default is to cache strings locally.
EXAMPLES
Normal output:
bash# tdump
C Idx Delta-T Trace
= === ======== =====
0 35d newest syscall p=0xf07ee200 #0x3
0 35c ef syscall: re-entering kernel
0 35b 13c syscall: run user p=0xf07ee200
0 35a 8c syscall p=0xf07ee200 err=0 ret=f016800c
0 359 e6 syscall p=0xf07ee200 #0xc7
0 358 17f syscall: re-entering kernel
0 357 c78 syscall: run user p=0xf07ee200
0 356 c3 syscall p=0xf07ee200 err=0 ret=4
0 355 9c3 syscall p=0xf07ee200 #0x3
0 354 ef syscall: re-entering kernel
0 353 112 syscall: run user p=0xf07ee200
0 352 83 syscall p=0xf07ee200 err=0 ret=f019abe8
[...]
Verbose output:
bash# tdump-v
C Idx Time Stamp Delta-T T from start
= === ================ ======== ================
0 399 000027d9c0cdffdf newest
syscall p=0xf07ee200 #0x3
f07ee200 00000003 7fffa7a0 7fffefe0 f012bcbb
0 398 000027d9c0cdfef0 ef 000000ef
syscall: re-entering kernel
f014fc75 00000183 7fffa7a0 7fffa7a0 a0000200
0 397 000027d9c0cdfdd6 11a 00000209
syscall: run user p=0xf07ee200
f07ee200 00000183 7fffefe0 7fffa7a0 08060aa3
0 396 000027d9c0cdfd4e 88 00000291
syscall p=0xf07ee200 err=0 ret=f016800c
f07ee200 00000000 f016800c 7fffefe0 08060a90
0 395 000027d9c0cdfc99 b5 00000346
syscall p=0xf07ee200 #0xc7
f07ee200 000000c7 7fffa7a0 7fffefe0 a00c5ca6
FILES
/bsd Default kernel namelist.
/dev/kmem Default memory file.
SEE ALSOktr(4)
BSD/OS December 8, 1997 2
