trapstat(1M)
NAME
trapstat - report trap statistics
SYNOPSIS
/usr/platform/ platform-name /sbin/trapstat [-t | -T |
-e entry] [-C processor_set_id | -c cpulist] [-P] [-a] [-
r rate] [ [ interval [count]] | command | [args]]
/usr/platform/ platform-name /sbin/trapstat -l
DESCRIPTION
The trapstat utility gathers and displays run-time trap
statistics on UltraSPARC-based systems. The default output
is a table of trap types and CPU IDs, with each row of the
table denoting a trap type and each column of the table
denoting a CPU. If standard output is a terminal, the table
contains as many columns of data as can fit within the ter-
minal width; if standard output is not a terminal, the table
contains at most six columns of data. By default, data is
gathered and and displayed for all CPUs; if the data cannot
fit in a single table, it is printed across multiple tables.
The set of CPUs for which data is gathered and displayed can
be optionally specified with the -c or -C option.
Unless the -r option or the -a option is specified, the
value displayed in each entry of the table corresponds to
the number of traps per second. If the -r option is speci-
fied, the value corresponds to the number of traps over the
interval implied by the specified sampling rate; if the -a
option is specified, the value corresponds to the accumu-
lated number of traps since the invocation of trapstat.
By default, trapstat displays data once per second, and runs
indefinitely; both of these behaviors can be optionally con-
trolled with the interval and count parameters, respec-
tively. The interval is specified in seconds; the count
indicates the number of intervals to be executed before
exiting. Alternatively, command can be specified, in which
case trapstat executes the provided command and continues to
run until the command exits. A positive integer is assumed
to be an interval; if the desired command cannot be dis-
tinguished from an integer, the full path of command must be
specified.
UltraSPARC I, II and III handle translation lookaside buffer
(TLB) misses by trapping to the operating system. TLB miss
traps can be a significant component of overall system per-
formance for some workloads; the -t option provides in-depth
information on these traps. When run with this option,
trapstat displays both the rate of TLB miss traps and the
percentage of time spent processing those traps. Addition-
ally, TLB misses that hit in the translation storage buffer
(TSB) are differentiated from TLB misses that further miss
in the TSB. (The TSB is a software structure used as a
translation entry cache to allow the TLB to be quickly
filled; it is discussed in detail in the UltraSPARC I&II
User's Manual.) The TLB and TSB miss information is further
broken down into user- and kernel-mode misses.
Workloads with working sets that exceed the TLB reach may
spend a significant amount of time missing in the TLB. To
accommodate such workloads, the operating system supports
multiple page sizes: larger page sizes increase the effec-
tive TLB reach and thereby reduce the number of TLB misses.
To provide insight into the relationship between page size
and TLB miss rate, trapstat optionally provides in-depth TLB
miss information broken down by page size using the -T
option. The information provided by the -T option is a
superset of that provided by the -t option; only one of -t
and -T can be specified.
OPTIONS
The following options are supported:
-a Displays the number of traps as accumulating, monoton-
ically increasing values instead of per-second or
per-interval rates.
-c cpulist
Enables trapstat only on the CPUs specified by cpu-
list.
cpulist can be a single processor ID (for example, 4),
a range of processor IDs (for example, 4-6), or a
comma separated list of processor IDs or processor ID
ranges (for example, 4,5,6 or 4,6-8).
-C processor_set_id
Enables trapstat only on the CPUs in the processor set
specified by processor_set_id.
trapstat modifies its output to always reflect the
CPUs in the specified processor set. If a CPU is added
to the set, trapstat modifies its output to include
the added CPU; if a CPU is removed from the set,
trapstat modifies its output to exclude the removed
CPU. At most one processor set can be specified.
-e entrylist
Enables trapstat only for the trap table entry or
entries specified by entrylist. A trap table entry can
be specified by trap number or by trap name (for exam-
ple, the level-10 trap can be specified as 74, 0x4A,
0x4a, or level-10).
entrylist can be a single trap table entry or a comma
separated list of trap table entries. If the specified
trap table entry is not valid, trapstat prints a table
of all valid trap table entries and values. A list of
valid trap table entries is also found in The SPARC
Architecture Manual, Version 9 and the Sun Microelec-
tronics UltraSPARC I&II User's Manual. If the parsable
option (-P) is specified in addition to the -e option,
the format of the data is as follows:
Field Contents
1 Timestamp (nanoseconds since start)
2 CPU ID
3 Trap number (in hexadecimal)
4 Trap name
5 Trap rate per interval
Each field is separated with whitespace. If the format
is modified, it will be modified by adding potentially
new fields beginning with field 6; exant fields will
remain unchanged.
-l Lists trap table entries. By default, a table is
displayed containing all valid trap numbers, their
names and a brief description. The trap name is used
in both the default output and in the entrylist param-
eter for the -e argument. If the parsable option (-P)
is specified in addition to the -l option, the format
of the data is as follows:
Field Contents
1 Trap number in hexadecimal
2 Trap number in decimal
3 Trap name
Remaining Trap description
-P Generates parsable output. When run without other data
gathering modifying options (that is, -e, -t or -T),
trapstat's the parsable output has the following for-
mat:
Field Contents
1 Timestamp (nanoseconds since start)
2 CPU ID
3 Trap number (in hexadecimal)
4 Trap name
5 Trap rate per interval
Each field is separated with whitespace. If the format
is modified, it will be modified by adding potentially
new fields beginning with field 6; extant fields will
remain unchanged.
-r rate
Explicitly sets the sampling rate to be rate samples
per second. If this option is specified, trapstat's
output changes from a traps-per-second to traps-per-
sampling-interval.
-t Enables TLB statistics.
A table is displayed with four principal columns of
data: itlb-miss, itsb-miss, dtlb-miss, and dtsb-miss.
The columns contain both the rate of the corresponding
event and the percentage of CPU time spent processing
the event. The percentage of CPU time is given only in
terms of a single CPU. The rows of the table
correspond to CPUs, with each CPU consuming two rows:
one row for user-mode events (denoted with u) and one
row for kernel-mode events (denoted with k). For each
row, the percentage of CPU time is totalled and
displayed in the rightmost column. The CPUs are del-
ineated with a solid line. If the parsable option (-P)
is specified in addition to the -t option, the format
of the data is as follows:
Field Contents
1 Timestamp (nanoseconds since start)
2 CPU ID
3 Mode (k denotes kernel, u denotes user)
4 I-TLB misses
5 Percentage of time in I-TLB miss handler
6 I-TSB misses
7 Percentage of time in I-TSB miss handler
8 D-TLB misses
9 Percentage of time in D-TLB miss handler
10 D-TSB misses
11 Percentage of time in D-TSB miss handler
Each field is separated with whitespace. If the format
is modified, it will be modified by adding potentially
new fields beginning with field 12; extant fields will
remain unchanged.
-T Enables TLB statistics, with page size information. As
with the -t option, a table is displayed with four
principal columns of data: itlb-miss, itsb-miss,
dtlb-miss, and dtsb-miss. The columns contain both the
absolute number of the corresponding event, and the
percentage of CPU time spent processing the event. The
percentage of CPU time is given only in terms of a
single CPU. The rows of the table correspond to CPUs,
with each CPU consuming two sets of rows: one set for
user-level events (denoted with u) and one set for
kernel-level events (denoted with k). Each set, in
turn, contains as many rows as there are page sizes
supported (see getpagesizes(3C)). For each row, the
percentage of CPU time is totalled and displayed in
the right-most column. The two sets are delineated
with a dashed line; CPUs are delineated with a solid
line. If the parsable option (-P) is specified in
addition to the -T option, the format of the data is
as follows:
Field Contents
1 Timestamp (nanoseconds since start)
2 CPU ID
3 Mode k denotes kernel, u denotes user)
4 Page size, in decimal
5 I-TLB misses
6 Percentage of time in I-TLB miss handler
7 I-TSB misses
8 Percentage of time in I-TSB miss handler
9 D-TLB misses
10 Percentage of time in D-TLB miss handler
11 D-TSB misses
12 Percentage of time in D-TSB miss handler
Each field is separated with whitespace. If the format
is modified, it will be modified by adding potentially
new fields beginning with field 13; extant fields will
remain unchanged.
EXAMPLES
Example 1: Using trapstat Without Options
When run without options, trapstat displays a table of trap
types and CPUs. At most six columns can fit in the default
terminal width; if (as in this example) there are more than
six CPUs, multiple tables are displayed:
example# trapstat
vct name | cpu0 cpu1 cpu4 cpu5 cpu8 cpu9
------------------------+------------------------------------------------------
24 cleanwin | 6446 4837 6368 2153 2623 1321
41 level-1 | 100 0 0 0 1 0
44 level-4 | 0 1 1 1 0 0
45 level-5 | 0 0 0 0 0 0
47 level-7 | 0 0 0 0 9 0
49 level-9 | 100 100 100 100 100 100
4a level-10 | 100 0 0 0 0 0
4d level-13 | 6 10 7 16 13 11
4e level-14 | 100 0 0 0 1 0
60 int-vec | 2607 2740 2642 2922 2920 3033
64 itlb-miss | 3129 2475 3167 1037 1200 569
68 dtlb-miss | 121061 86162 109838 37386 45639 20269
6c dtlb-prot | 997 847 1061 379 406 184
84 spill-user-32 | 2809 2133 2739 200806 332776 454504
88 spill-user-64 | 45819 207856 93487 228529 68373 77590
8c spill-user-32-cln | 784 561 767 274 353 215
90 spill-user-64-cln | 9 37 17 39 12 13
98 spill-kern-64 | 62913 50145 63869 21916 28431 11738
a4 spill-asuser-32 | 1327 947 1288 460 572 335
a8 spill-asuser-64 | 26 48 18 54 10 14
ac spill-asuser-32-cln | 4580 3599 4555 1538 1978 857
b0 spill-asuser-64-cln | 26 0 0 2 0 0
c4 fill-user-32 | 2862 2161 2798 191746 318115 435850
c8 fill-user-64 | 45813 197781 89179 217668 63905 74281
cc fill-user-32-cln | 3802 2833 3733 10153 16419 19475
d0 fill-user-64-cln | 329 10105 4873 10603 4235 3649
d8 fill-kern-64 | 62519 49943 63611 21824 28328 11693
108 syscall-32 | 2285 1634 2278 737 957 383
126 self-xcall | 100 0 0 0 0 0
vct name | cpu12 cpu13 cpu14 cpu15
------------------------+------------------------------------
24 cleanwin | 5435 4232 6302 6104
41 level-1 | 0 0 0 0
44 level-4 | 2 0 0 1
45 level-5 | 0 0 0 0
47 level-7 | 0 0 0 0
49 level-9 | 100 100 100 100
4a level-10 | 0 0 0 0
4d level-13 | 15 11 22 11
4e level-14 | 0 0 0 0
60 int-vec | 2813 2833 2738 2714
64 itlb-miss | 2636 1925 3133 3029
68 dtlb-miss | 90528 70639 107786 103425
6c dtlb-prot | 819 675 988 954
84 spill-user-32 | 175768 39933 2811 2742
88 spill-user-64 | 0 241348 96907 118298
8c spill-user-32-cln | 681 513 753 730
90 spill-user-64-cln | 0 42 16 20
98 spill-kern-64 | 52158 40914 62305 60141
a4 spill-asuser-32 | 1113 856 1251 1208
a8 spill-asuser-64 | 0 64 16 24
ac spill-asuser-32-cln | 3816 2942 4515 4381
b0 spill-asuser-64-cln | 0 0 0 0
c4 fill-user-32 | 170744 38444 2876 2784
c8 fill-user-64 | 0 230381 92941 111694
cc fill-user-32-cln | 8550 3790 3612 3553
d0 fill-user-64-cln | 0 10726 4495 5845
d8 fill-kern-64 | 51968 40760 62053 59922
108 syscall-32 | 1839 1495 2144 2083
126 self-xcall | 0 0 0 0
Example 2: Using trapset with CPU Filtering
The -c option can be used to limit the CPUs on which
trapstat is enabled. This example limits CPU 1 and CPUs 12
through 15.
example# trapstat -c 1,12-15
vct name | cpu1 cpu12 cpu13 cpu14 cpu15
------------------------+---------------------------------------------
24 cleanwin | 6923 3072 2500 3518 2261
44 level-4 | 3 0 0 1 1
49 level-9 | 100 100 100 100 100
4d level-13 | 23 8 14 19 14
60 int-vec | 2559 2699 2752 2688 2792
64 itlb-miss | 3296 1548 1174 1698 1087
68 dtlb-miss | 114788 54313 43040 58336 38057
6c dtlb-prot | 1046 549 417 545 370
84 spill-user-32 | 66551 29480 301588 26522 213032
88 spill-user-64 | 0 318652 111239 299829 221716
8c spill-user-32-cln | 856 347 331 416 293
90 spill-user-64-cln | 0 55 21 59 39
98 spill-kern-64 | 66464 31803 24758 34004 22277
a4 spill-asuser-32 | 1423 569 560 698 483
a8 spill-asuser-64 | 0 74 32 98 46
ac spill-asuser-32-cln | 4875 2250 1728 2384 1584
b0 spill-asuser-64-cln | 0 2 0 1 0
c4 fill-user-32 | 64193 28418 287516 27055 202093
c8 fill-user-64 | 0 305016 106692 288542 210654
cc fill-user-32-cln | 6733 3520 15185 2396 12035
d0 fill-user-64-cln | 0 13226 3506 12933 11032
d8 fill-kern-64 | 66220 31680 24674 33892 22196
108 syscall-32 | 2446 967 817 1196 755
Example 3: Using trapstat with TLB Statistics
The -t option displays in-depth TLB statistics, including
the amount of time spent performing TLB miss processing. The
following example shows that the machine is spending 14.1
percent of its time just handling D-TLB misses:
example# trapstat -t
cpu m| itlb-miss %tim itsb-miss %tim | dtlb-miss %tim dtsb-miss %tim |%tim
-----+-------------------------------+-------------------------------+----
0 u| 2571 0.3 0 0.0 | 10802 1.3 0 0.0 | 1.6
0 k| 0 0.0 0 0.0 | 106420 13.4 184 0.1 |13.6
-----+-------------------------------+-------------------------------+----
1 u| 3069 0.3 0 0.0 | 10983 1.2 100 0.0 | 1.6
1 k| 27 0.0 0 0.0 | 106974 12.6 19 0.0 |12.7
-----+-------------------------------+-------------------------------+----
2 u| 3033 0.3 0 0.0 | 11045 1.2 105 0.0 | 1.6
2 k| 43 0.0 0 0.0 | 107842 12.7 108 0.0 |12.8
-----+-------------------------------+-------------------------------+----
3 u| 2924 0.3 0 0.0 | 10380 1.2 121 0.0 | 1.6
3 k| 54 0.0 0 0.0 | 102682 12.2 16 0.0 |12.2
-----+-------------------------------+-------------------------------+----
4 u| 3064 0.3 0 0.0 | 10832 1.2 120 0.0 | 1.6
4 k| 31 0.0 0 0.0 | 107977 13.0 236 0.1 |13.1
=====+===============================+===============================+====
ttl | 14816 0.3 0 0.0 | 585937 14.1 1009 0.0 |14.5
Example 4: Using trapstat with TLB Statistics and Page Size
Information
By specifying the -T option, trapstat shows TLB misses bro-
ken down by page size. In this example, CPU 0 is spending
7.9 percent of its time handling user-mode TLB misses on 8K
pages, and another 2.3 percent of its time handling user-
mode TLB misses on 64K pages.
example# trapstat -T -c 0
cpu m size| itlb-miss %tim itsb-miss %tim | dtlb-miss %tim dtsb-miss %tim |%tim
----------+-------------------------------+-------------------------------+----
0 u 8k| 1300 0.1 15 0.0 | 104897 7.9 90 0.0 | 8.0
0 u 64k| 0 0.0 0 0.0 | 29935 2.3 7 0.0 | 2.3
0 u 512k| 0 0.0 0 0.0 | 3569 0.2 2 0.0 | 0.2
0 u 4m| 0 0.0 0 0.0 | 233 0.0 2 0.0 | 0.0
- - - - - + - - - - - - - - - - - - - - - + - - - - - - - - - - - - - - - + - -
0 k 8k| 13 0.0 0 0.0 | 71733 6.5 110 0.0 | 6.5
0 k 64k| 0 0.0 0 0.0 | 0 0.0 0 0.0 | 0.0
0 k 512k| 0 0.0 0 0.0 | 0 0.0 206 0.1 | 0.1
0 k 4m| 0 0.0 0 0.0 | 0 0.0 0 0.0 | 0.0
==========+===============================+===============================+====
ttl | 1313 0.1 15 0.0 | 210367 17.1 417 0.2 |17.5
Example 5: Using trapstat with Entry Filtering
By specifying the -e option, trapstat displays statistics
for only specific trap types. Using this option minimizes
the probe effect when seeking specific data. This example
yields statistics for only the dtlb-prot and syscall-32
traps on CPUs 12 through 15:
example# trapstat -e dtlb-prot,syscall-32 -c 12-15
vct name | cpu12 cpu13 cpu14 cpu15
------------------------+------------------------------------
6c dtlb-prot | 817 754 1018 560
108 syscall-32 | 1426 1647 2186 1142
vct name | cpu12 cpu13 cpu14 cpu15
------------------------+------------------------------------
6c dtlb-prot | 1085 996 800 707
108 syscall-32 | 2578 2167 1638 1452
Example 6: Using trapstat with a Higher Sampling Rate
The following example uses the -r option to specify a sam-
pling rate of 1000 samples per second, and filter only for
the level-10 trap. Additionally, specifying the -P option
yields parsable output.
Notice the timestamp difference between the level-10 events:
9,998,000 nanoseconds and 10,007,000 nanoseconds. These
level-10 events correspond to the system clock, which by
default ticks at 100 hertz (that is, every 10,000,000
nanoseconds).
example# trapstat -e level-10 -P -r 1000
1070400 0 4a level-10 0
2048600 0 4a level-10 0
3030400 0 4a level-10 1
4035800 0 4a level-10 0
5027200 0 4a level-10 0
6027200 0 4a level-10 0
7027400 0 4a level-10 0
8028200 0 4a level-10 0
9026400 0 4a level-10 0
10029600 0 4a level-10 0
11028600 0 4a level-10 0
12024000 0 4a level-10 0
13028400 0 4a level-10 1
14031200 0 4a level-10 0
15027200 0 4a level-10 0
16027600 0 4a level-10 0
17025000 0 4a level-10 0
18026000 0 4a level-10 0
19027800 0 4a level-10 0
20025600 0 4a level-10 0
21025200 0 4a level-10 0
22025000 0 4a level-10 0
23035400 0 4a level-10 1
24027400 0 4a level-10 0
25026000 0 4a level-10 0
26027000 0 4a level-10 0
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWcsu |
| Interface Stability | |
| Human Readable Output | Unstable |
| Parsable Output | Evolving |
|_____________________________|_____________________________|
SEE ALSO
lockstat(1M), pmap(1), psrset(1M), psrinfo(1M), pbind(1M),
ppgsz(1), getpagesizes(3C)
Sun Microelectronics UltraSPARC I&II User's Manual, January
1997, STP1031,
The SPARC Architecture Manual, Version 9, 1994, Prentice-
Hall.
NOTES
When enabled, trapstat induces a varying probe effect,
depending on the type of information collected. While the
precise probe effect depends upon the specifics of the
hardware, the following table can be used as a rough guide:
Option Approximate probe effect
default 3-5% per trap
-e 3-5% per specified trap
-t, -T 40-45% per TLB miss trap hitting in
the TSB, 25-30% per TLB miss trap
missing in the TSB
These probe effects are per trap not for the system as a
whole. For example, running trapstat with the default
options on a system that spends 7% of total time handling
traps induces a performance degradation of less than one
half of one percent; running trapstat with the -t or -T
option on a system spending 5% of total time processing TLB
misses induce a performance degradation of no more than
2.5%.
When run with the -t or -T option, trapstat accounts for its
probe effect when calculating the %tim fields. This assures
that the %tim fields are a reasonably accurate indicator of
the time a given workload is spending handling TLB misses -
regardless of the perturbing presence of trapstat.
While the %tim fields include the explicit cost of executing
the TLB miss handler, they do not include the implicit costs
of TLB miss traps (for example, pipeline effects, cache pol-
lution, etc). These implicit costs become more significant
as the trap rate grows; if high %tim values are reported
(greater than 50%), you can accurately infer that much of
the balance of time is being spent on the implicit costs of
the TLB miss traps.
Due to the potential system wide degradation induced, only
the super-user can run trapstat.
Due to the limitation of the underlying statistics gathering
methodology, only one instance of trapstat can run at a
time.
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