spot_diff(1)spot_diff(1)NAMEspot_diff - compare the output of two or more spot runs and write
results to a HTML file to be viewed in a browser.
SYNOPSISspot_diff [-h -V] [-a -c -f -q -s] [-d directory name ] [-e experiment
name ] [-o file name ]
DESCRIPTION
The spot_diff command reads the output from user-selected spot experi‐
ments and creates a HTML document that lists and compares important
metrics for each experiment in dynamically sortable tables. Differ‐
ences exceeding set thresholds are highlighted to bring attention to
possible performance-related problems. The following sections of a
spot_diff report may appear depending on a system's installed software,
a microprocessor's debug features, and privileges of the user that ran
the spot experiments:
Key Experiment Metrics: This table includes elapsed/user/system
time, instruction count, IPC, bandwidth data (if available), mem‐
ory use and machine name.
Top Stalls: Generic stall information from ripc typically includes
the derived metrics "D-Cache", "E-Cache", "FPU use", "IU use",
"Instruction Issue", "RAW Miss" and "Store Queue".
BIT Instruction Counts: If instruction frequency data was gathered
by spot, a table of top opcode counts is printed.
Flags report: This table lists compilation flags used with each
compiler (e.g. cc, CC, f90). Flags that were not used in every
invocation of a particular compiler appear highlighted in bold red
text.
Traps: Top OS traps that show large variance between experiments
are listed.
Time Spent in Top Functions: The functions with highest exclusive
user time in each selected experiment appear in this table in
alphanumeric order.
OPTIONS
If invoked with no arguments, all valid spot experiments in the current
directory will be compared and output will be written to the file
./spot_diff.html.
The following options are supported:
-a The last column in the Key Metrics and Function Profiles tables
will be an average of the values in each row.
-c Generate spot_diff.csv spreadsheet in current directory in addi‐
tion to the HTML output. The file name may be changed with the -o
flag.
-d directory
Every valid spot experiment in the specified directory will be
compared. Multiple -d flags are allowed. Default is current
directory.
-e experiment name
Specifies an experiment's directory name to include in the
spot_diff comparison. Multiple -e flags are allowed and can be
used with or without -d.
-f Fast run (flags and traps reports are not generated).
-h Print help information.
-o output file name
Default is spot_diff.[html|csv] in current directory. The proper
extension (.html or .csv) will be added automatically. Absolute
paths may be given to change the location of the output.
-q Quiet run (STDOUT messages suppressed).
-s Snip (as opposed to wrap) long names in the HTML report to fit in
narrow columns Ex.: abcdefghijk becomes abc..hijk as opposed to
the default abcdefghi<break>jk
-V Print version information.
EXAMPLES
Consider the following directory structure:
/tmp/d1/exp1
/tmp/d1/exp2
/tmp/d2/exp1
The following three invocations compare all experiments in /tmp/d1:
1) cd /tmp/d1; spot_diff
2) spot_diff-d /tmp/d1
3) spot_diff-e /tmp/d1/exp1 -e /tmp/d1/exp2
The following two invocations compare all three experiments in /tmp:
1) spot_diff-d /tmp/d1 -e /tmp/d2/exp1
2) spot_diff-e /tmp/d1/exp1 -e /tmp/d1/exp2 -e /tmp/d2/exp1
The only invocation that compares just the experiments /tmp/d1/exp1 and
/tmp/d2/exp1 is:
spot_diff-e /tmp/d1/exp1 -e /tmp/d2/exp1
SEE ALSOspot(1), er_html(1), ripc(1), and the Spot User's Guide manual.
January 2007 spot_diff(1)
