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dcpistats(1)
NAME
dcpistats - Print statistics comparing sets of profile data
SYNOPSIS
dcpistats [flags] [-set] [-factor n] profile_selection_spec [...]
DESCRIPTION
Dcpistats compares sets of raw sample counts and prints various statistics
about them. Dcpistats is useful for comparing variations across multiple
runs of the same program, or for comparing differences between slightly different
versions of a program.
It runs dcpiprof(1) for each set of samples
(separated by the -set flag), parses the output and prints the range
-- the difference between the maximum and the minimum sample count -- for
each procedure (or image) across all sample sets. The entries are sorted
by range, so that procedures (or images) with the largest differences appear
at the top of the listing. If the -norm flag is set, then the normalized
range is used instead of the range, where the normalized range is the range
expressed as a percentage of the total samples for an entry.
The image files can be the same or different across different sample sets.
Dcpistats bins the data according to procedure name (or image name with -i).
The -show_images flag can be used to list the images in which each
procedure appears.
FLAGS
- -set
- Denote the start of a set of sample files. All samples within a set
are combined, and samples across different sets are compared. Any number
of sets is acceptable. The -set flag can be omitted if the only
set-specific arguments are the image names, i.e., each set can be described
using only its image name. In this case, all non-flag command-line arguments
are treated as images in separate sets.
- -V
- Print out the version number.
- -i
- Print statistics per image (default is per procedure).
- -cutoff percentage
- Don't print procedures with ranges (i.e., the difference between
the maximum and the minimum sample count) less than percentage of
the total range between sets.
- -norm
- Sort by and print normalized ranges (default is to sort by the
absolute value of the range).
- -range_value
- Sort by range value (default is to sort by the absolute
value of the range). This option is useful when comparing
two sets of samples to see why one is faster than the other.
Procedures that have more samples in set #2 show up at the
top of the listing (with a positive range), and procedures
that have more samples in set #1 end up at the bottom (with
a negative range). If both -norm and -range_value are
set, then -norm is used.
- -all_stats
- Print all statistics. This prints the mean, standard deviation,
minimum and maximum of the sample counts across sets for
each procedure.
- -range_only
- Only print ranges, don't print sample
counts (ignored if -all_stats is
set).
- -show_images
- Print
the images
in which
each procedure
appears (ignored
if -i is
set).
- -s
event
- Sort
by
event event.
Default
is
cycles.
- -m
map-file-name
- Use
specified
map
file
generated
by dcpiscan(1) for
associating
profiles
with
named
images.
This
option
can
be
repeated,
allowing
several
map
files
to
be
specified;
information
from
all
of
the
supplied
map
files
is
merged.
The -m option
works
like
the -p option,
except
that
instead
of
specifying
one
image
at
a
time,
a
whole
set
of
images
can
be
entered
into
a
map
file
via dcpiscan(1) and
the
entire
set
can
be
specified
with
one
command
line
option.
- -p
image-file-name
- Use
the
specified
image
file
as
a
candidate
when
associating
profiles
with
named
image
files.
This
option
can
be
repeated,
allowing
several
image
names
to
be
specified
on
the
command
line.
- -factor
n
- Scale
the
samples
in
the
set
by n.
The
sample
counts
in
the
set
are
multiplied
by n.
This
option
applies
to
each
set
individually.
PROFILE SELECTION FLAGS
By default, this command automatically finds all of the relevant profile
files. The following options can be used to guide the search for the profile
files.
- -db <directory name>
- Search for profile files in the specified profile database directory.
The directory name should be the same name as the one specified when dcpid was
started. If this option is not specified, the directory name is obtained
from the DCPIDB environment variable. If neither this option,
nor the DCPIDB environment variable are set, the name of the directory
used by the last invocation of dcpid on this machine is used.
If none of these methods succeed in finding the appropriate directory,
and no explicit set of profile files is provided via the -profiles option,
then the command fails.
- -epoch latest
- Search for profile files in the latest epoch. This is the default.
- -epoch latest-k
- Search for profile files in the "k+1"th oldest epoch. For example,
search in the third oldest epoch if -epoch latest-2 is specified.
- -epoch <name>
- Search for profile files in the named epoch. The epoch name should
be the name of a subdirectory corresponding to a single epoch within
the profile database directory. Epoch subdirectory names usually take
the form YYYYMMDDHHMM (year-month-day-hours-minutes). For example,
an epoch started on June 11, 2002 at 22:33 would be named 200206112233.
If an epoch is given a symbolic name by creating a symbol link to the
actual epoch directory, then the symbolic name can also be used as an
argument to the -epoch option.
- -epoch all
- Search for profile files in all epochs.
- -ihost <hostnames...> --
- Include just those profile files associated with the specified
host names. The list of host names must be terminated either
via -- or by the end of the option list. The command prints
an error message and fails if both the -ihost and -ehost
options are specified.
- -ehost <hostnames...> --
- Exclude
any profile
files associated
with the
specified
host names.
The list
of host names
must be terminated
either via
-- or by
the end of
the option
list. The
command prints
an error
message and
fails if
both the
-ihost and
-ehost options
are specified.
- -label <label>
- Search
for
profile
files
with
the
specified
label(s)
(see dcpilabel(1)).
This
option
can
be
repeated
multiple
times.
If
no
labels
are
specified
on
the
command
line,
profile
file
labels
are
ignored
entirely.
If
any
labels
are
specified
on
the
command
line,
only
profile
files
that
have
one
of
the
specified
labels
are
used.
- -profiles <file
names...> --
- Use
just
the
profile
files
named
by
the
specified
file
names.
The
list
of
profile
file
names
can
be
terminated
either
via --,
or
by
the
end
of
the
option
list.
The
command
prints
an
error
message
and
fails
if
the -profiles option
is
used
in
conjunction
with
any
of
the
earlier
automatic
profile
finding
options.
(Use
the
automatic
profile
lookup
mechanism,
or
explicitly
name
the
profile
file
with
the -profile option;
but
don't
do
both.)
STATISTIC SELECTION FLAGS
Different kinds of performance counter statistics are available on various
models of Alpha CPUs. Alpha 21064/EV4, 21164/EV5 and 21264/EV6 CPUs have
traditional aggregate event counters. Alpha 21264A/EV67 and later processors
have a mix of some traditional aggregate event counters and newer ProfileMe
counters which allow accurate and precise instruction execution profiles
on out-of-order processors. (See dcpiprofileme(1) for
more information on ProfileMe statistics.)
The default statistic selection on an aggregate counter machine is to select
all the aggregate events. The default on a ProfileMe machine is to select
ProfileMe retire delay, retire count, !retired (i.e. aborted) count, !notrap
(i.e. trap) count, and aggregate cycles.
The options below can be used to select various statistics when available.
Use -event for aggregate statistics and -pm for ProfileMe
statistics. Note: there can be multiple, mixed -event and -pm specifications.
You can also specify the ratio of two statistics (written as stat1::stat2).
- -pm pm_stat(+pm_stat)
- Select the specified ProfileMe statistic plus any added in by optional +pm_stat specifications.
For example, select various trap statistics by specifying the option -pm
trap+replays+ldstorder+mispredict.
- -pm default(+pm_stat)
- Select the default set of ProfileMe statistics plus those added in by +pm_stat specifications.
At least one additional statistic is mandatory; -pm default without
modifications is extraneous and not allowed. The additional ProfileMe statistics
will take the place of the aggregate cycles statistic which is selected
by default.
- -pm all(-pm_stat)
- Select all ProfileMe statistics less those subtracted out. You can
repeat the optional -pm_stat specification to deselect multiple
ProfileMe statistics. Note: there are a lot of ProfileMe statistics.
Unless you deselect a bunch of them, this will select more statistics
than are appropriate for human consumption.
- -event ag_stat(+ag_stat)
- Select the specified aggregate statistic plus any added in by optional +ag_stat specifications.
For example, select cycles, icache misses, and data cache misses when
the option -event cycles+imiss+dmiss is specified.
- -event all(-ag_stat)
- Select all aggregate statistics less those subtracted out. You can
repeat the optional -ag_stat specification to deselect multiple
aggregate statistics.
- -allevents
- Select profile events corresponding to all event types, both aggregate
and ProfileMe. However, if there are ProfileMe events, this will produce
a large number of statistics, which in most cases will not be useful.
EXAMPLE USAGE
- dcpistats -i -set -epoch latest -set -epoch latest-1 -set -epoch
latest-2
- Use dcpistats to compare images across the last three epochs.
- dcpistats -set -factor 1.5 -epoch latest prog -set -epoch latest-1
prog
- Use dcpistats to compare runs of the program prog in two
different epochs. All sample counts in the first set are multiplied by
1.5.
- dcpistats -epoch latest prog1 prog2
- Use dcpistats to compare runs of the programs prog1 and prog2 in
the same epoch.
INTERPRETING THE OUTPUT
Dcpistats prints a header that summarizes the sample counts for each event
type and each sample set. Similar to dcpiprof(1),
if per-image profiles are being produced, there is a line per image in the
body of the listing, and the last column in the line is the name of the image.
Otherwise there is a line per procedure and the last column is the name of
the procedure.
For example, consider the following output, generated with the command: dcpistats
-cutoff 10 prog1 prog2:
=======================================================================
Total number of samples for each set:
Set# Set name cycles dmiss imiss
1 prog1 9210 1138 54
2 prog2 862 141 9
9210 cycles samples for set ``prog1'' is the maximum
862 cycles samples for set ``prog2'' is the minimum
8348 is the total range
Printing entries where the absolute value of the range
is at least 834 cycles samples (10% of total range)
=======================================================================
cycles dmiss imiss
----------------- ----- -----
range set1 set2 range range procedure
-8340 9139 799 -1001 -47 main
1796 3639 5435 23 12 calc
...
Dcpistats is comparing the profiles for two sample sets in the same epoch;
the first set contains samples for the program prog1, and the second
set contains samples for the program prog2. Both sample sets contain
data for three events, cycles, dmiss (data cache misses)
and imiss (instruction cache misses).
The header lists the number of samples of each event type for both sample
sets. It also lists the minimum and maximum number of cycle samples,
along with the range. Since a cutoff value of 10 was specified on the command-line,
the body of the listing will only include those procedures that have ranges
of at least 834 cycle samples (10% of the total range of 8348).
The first column lists the range of cycle samples. The sample sets are
ordered, so a negative range means that the set with the maximum cycle samples
had a lower set number than the set with the minimum cycle samples. In the
above example, set #1 has 9139 cycle samples and set #2 has 799 cycle samples,
resulting in a range of -8340. The output is sorted by the absolute values
of the ranges, so that procedures with larger absolute differences appear
at the top of the listing. The -range_value flag can be used to
sort the output by the actual value of the range instead of the absolute
value. The positive ranges would show up at the top of the listing (i.e.,
those procedures in which set #2 has more cycle samples than set #1), and
the negative ranges would end up at the bottom of the listing.
The next two columns list the number of cycle samples for the procedure
in each of the sample sets. If the -range_only flag were set, then
these columns containing the number of samples would be omitted. The remaining
columns report the ranges for the secondary events, in this example, dmiss and imiss.
SEE ALSO
dcpi(1), dcpi2bb(1), dcpi2pix(1), dcpi2ps(1), dcpicalc(1), dcpicat(1), dcpicc(1), dcpicoverage(1), dcpictl(1), dcpid(1), dcpidiff(1), dcpidis(1), dcpiepoch(1), dcpiflow(1), dcpiflush(1), dcpikdiff(1), dcpilabel(1), dcpildlatency(1), dcpilist(1), dcpiprof(1), dcpiprofileme(1), dcpiquit(1), dcpiscan(1), dcpisource(1), dcpisumxct(1), dcpitar(1), dcpitopcounts(1), dcpitopstalls(1), dcpiuninstall(1), dcpiupcalls(1), dcpivarg(1), dcpivcat(1), dcpiversion(1), dcpivlst(1), dcpivprofiler(1), dcpiwhatcg(1), dcpix(1), dcpiformat(4), dcpiexclusions(4)
For more information, see the DCPI project home page http://h30097.www3.hp.com/dcpi.
COPYRIGHT
Copyright 1996-2004, Hewlett-Packard Company.
All rights reserved.
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