An example that uses ls

Change-Id: I77c6386ad4238c681da90c4b59445a0f0c56b303

3 files changed, 164 insertions, 0 deletions

diff --git a/README b/README
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+++ b/README
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+See ls* for an example of how to use this thing
+
+But beware that the breakpoints in ls.gdb are rather specific to my /bin/ls.
diff --git a/ls.gdb b/ls.gdb
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index 0000000..073740d
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+++ b/ls.gdb
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+#This script quite sensitive to OS differences. On some targets it doesn't work at all.
+#I don't really trust the process handling.
+
+python
+
+import os
+import sys
+import subprocess
+import signal
+import locale
+import time
+locale.setlocale(locale.LC_ALL, 'en_GB.UTF8')
+
+if not 'PERF_COUNTERS' in os.environ or os.environ['PERF_COUNTERS'] == '':
+  os.environ['PERF_COUNTERS']='task-clock context-switches cpu-migrations page-faults cycles instructions branch-misses'
+counter_list=os.environ['PERF_COUNTERS'].split()
+counter_results=dict.fromkeys(counter_list, 0)
+
+end
+
+set follow-fork-mode child
+
+#doesn't seem to work properly
+set print inferior-events off
+
+break *0x402ca0
+commands
+  silent
+  python
+
+try:
+  #This is more complex than comma-separating a single -e, but gives clearer errors when one event is unsupported
+  args = ['/usr/bin/perf', 'stat', '-p', str(gdb.selected_inferior().pid)]
+  for x in counter_list:
+    args.extend(['-e', x])
+
+  perfproc = subprocess.Popen(args, stderr=subprocess.PIPE)
+  time.sleep(1) #Yuck. Need to give perf a moment to start up, though.
+except OSError, e:
+  if e.errno == errno.ENOENT:
+    sys.stderr.write("*** /usr/bin/perf does not exist\n")
+  else:
+    sys.stderr.write("*** Error %d while executing %s\n" % (e.errno, ' '.join(args)))
+  raise
+except:
+  sys.stderr.write("*** Error while executing %s\n" % ' '.join(args))
+  raise
+
+  end
+  c
+end
+
+break *0x402ce4
+commands
+  silent
+  python
+
+try:
+  perfproc.send_signal(signal.SIGINT) #Can this kill random processes? One would hope that Popen is sensible in this respect, but I don't know that it is. We don't expect perf to have exited in the normal case, though.
+  stdoutdata, stderrdata = perfproc.communicate()
+  lines = stderrdata.decode('utf-8').splitlines()
+  #sys.stderr.write('\n'.join(lines) + '\n')
+  for line in lines[3:-3]:
+    words = line.split()
+    counter_results[words[1]] += locale.atof(words[0])
+except OSError, e: #On newer pythons, would ProcessLookupError - but that's a subclass of OSError, so this should be close enough
+  if e.errno == errno.ESRCH:
+    sys.stderr.write("*** Failed to kill perf process %d\n" % perfproc.pid)
+    stdoutdata, stderrdata = perfproc.communicate()
+    if stdoutdata != None:
+      sys.stdout.write(stdoutdata.decode('utf-8') + '\n')
+    if stderrdata != None:
+      sys.stderr.write(stderrdata.decode('utf-8') + '\n')
+    if perfproc.returncode == None:
+      sys.stderr.write("*** perf process still appears to be running\n")
+    else:
+      sys.stderr.write("*** perf process exited early with code %d\n" % perfproc.returncode)
+  raise
+
+  end
+  c
+end
+
+#Work around set print inferior-events off not working properly
+break exit
+commands
+  silent
+  #This works in principle, but gdb seems buggy
+  #python gdb.execute('detach inferior %s' % str(gdb.selected_inferior().num))
+
+  #This works in practice for this case
+  #detach inferior 2
+  python
+
+for counter in counter_list:
+  sys.stderr.write(counter + ' ' + locale.str(counter_results[counter]) + '\n')
+
+  end
+  c
+end
+
+run
+q
diff --git a/lsgun.sh b/lsgun.sh
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+++ b/lsgun.sh
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+#!/bin/bash
+#Simple example running on ls
+set -o pipefail
+set -u
+
+#Typically one would adjust these things at the top
+GDBSCRIPT=ls.gdb
+BINARIES='/bin/ls' #Binary(s) to run - just ls in this case, but a real case might have alternative builds
+BINARY_ARGS='.' #Sets of args to run - just . in this case, but a real case might have different parameters to explore
+OFFLOAD_MASK=0x1 #Core to run all non-profiled tasks on
+declare -A CORE_COUNTER
+#All perf events in A53 TRM, associated with taskset mask for an A53 on Juno
+CORE_COUNTER[0x02]=A53_COUNTERS[@]
+A53_COUNTERS=(\'\' \
+              \'r00 r01 r02 r03 r04 r05\' \
+              \'r06 r07 r08 r09 r0A r0B\' \
+              \'r0C r0D r0E r0F r10 r11\' \
+              \'r12 r13 r14 r15 r16 r17\' \
+              \'r18 r19 r1A r1D r1E r60\' \
+              \'r61 r7A r86 r87 rC0 rC1\' \
+              \'rC2 rC3 rC4 rC5 rC6 rC7\' \
+              \'rC8 rC9 rCA rCB rCC rD0\' \
+              \'rD1 rD2 rE0 rE1 rE2 rE3\' \
+              \'rE4 rE5 rE6 rE7 rE8\')
+#All perf events in A57 TRM, associated with taskset mask for an A57 on Juno
+CORE_COUNTER[0x10]=A57_COUNTERS[@]
+A57_COUNTERS=(\'\' \
+              \'r00 r01 r02 r03 r04 r05\' \
+              \'r08 r09 r0A r0B r10 r11\' \
+              \'r12 r13 r14 r15 r16 r17\' \
+              \'r18 r19 r1A r1B r1C r1D\' \
+              \'r1E r40 r41 r42 r43 r46\' \
+              \'r47 r48 r4C r4D r50 r51\' \
+              \'r52 r53 r56 r57 r58 r60\' \
+              \'r61 r62 r63 r64 r65 r66\' \
+              \'r67 r68 r69 r6A r6C r6D\' \
+              \'r6E r70 r71 r72 r73 r74\' \
+              \'r75 r76 r77 r78 r79 r7A\' \
+              \'r7C r7D r7E r81 r82 r83\' \
+              \'r84 r86 r87 r88 r8A r8B\' \
+              \'r8C r8D r8E r8F r90 r91\')
+function doit
+{
+  for i in {1..30}; do #Number of times to run each condition. 30 in some vague hope of statistical validity.
+    echo : $binary $binary_args $i | tee -a ~/output.$$.${cpu}
+    taskset $cpu gdb -q -x ${GDBSCRIPT} --args $binary $binary_args 2>&1 >/dev/null | tee -a ~/output.$$.${cpu}
+  done
+}
+
+for cpu in "${!CORE_COUNTER[@]}"; do #This is the outer loop so that we stay on a single CPU for as long as possible
+  #for x in `ps -e | awk '{print $1}' | sed 1d`; do sudo taskset -p ${OFFLOAD_MASK} $x; done #Shunt as much as we can off the CPU of interest (i.e. onto a CPU that isn't in any mask that we are using)
+  rm -f ${HOME}/output.$$.${cpu} #Delete output from old run, should it exist
+  for binary in $BINARIES; do
+    for binary_args in $BINARY_ARGS; do
+      eval for PERF_COUNTERS in ${!CORE_COUNTER[${cpu}]}\; do export PERF_COUNTERS\; doit\; done
+    done
+  done
+done