gen_autofdo_event.py was stumbling on models with stepping so
I updated the script to handle this case similar to the code in
https://github.com/andikleen/pmu-tools/blob/c6a5f63aede19def8886d6a8b74d7a55c38ca947/event_download.py
The second change was to tolerate cases when the CPU supports PEBS but the
perf command with /p fails. This can happen in, e.g., a virtual machine.
I regenerated gcc-auto-profile using the updated script.
contrib/ChangeLog:
* gen_autofdo_event.py: handle stepping, non-working PEBS
gcc/ChangeLog:
* config/i386/gcc-auto-profile: regenerate
---
contrib/gen_autofdo_event.py | 54 ++--
gcc/config/i386/gcc-auto-profile | 41 +++-
2 files changed, 71 insertions(+), 24 deletions(-)
diff --git a/contrib/gen_autofdo_event.py b/contrib/gen_autofdo_event.py
index c97460c61c6..1eb6f1d6d85 100755
--- a/contrib/gen_autofdo_event.py
+++ b/contrib/gen_autofdo_event.py
@@ -46,20 +46,29 @@ args = ap.parse_args()
eventmap = collections.defaultdict(list)
-def get_cpu_str():
-with open('/proc/cpuinfo', 'r') as c:
-vendor, fam, model = None, None, None
-for j in c:
-n = j.split()
-if n[0] == 'vendor_id':
-vendor = n[2]
-elif n[0] == 'model' and n[1] == ':':
-model = int(n[2])
-elif n[0] == 'cpu' and n[1] == 'family':
-fam = int(n[3])
-if vendor and fam and model:
-return "%s-%d-%X" % (vendor, fam, model), model
-return None, None
+def get_cpustr():
+cpuinfo = os.getenv("CPUINFO")
+if cpuinfo is None:
+cpuinfo = '/proc/cpuinfo'
+f = open(cpuinfo, 'r')
+cpu = [None, None, None, None]
+for j in f:
+n = j.split()
+if n[0] == 'vendor_id':
+cpu[0] = n[2]
+elif n[0] == 'model' and n[1] == ':':
+cpu[2] = int(n[2])
+elif n[0] == 'cpu' and n[1] == 'family':
+cpu[1] = int(n[3])
+elif n[0] == 'stepping' and n[1] == ':':
+cpu[3] = int(n[2])
+if all(v is not None for v in cpu):
+break
+# stepping for SKX only
+stepping = cpu[0] == "GenuineIntel" and cpu[1] == 6 and cpu[2] == 0x55
+if stepping:
+return "%s-%d-%X-%X" % tuple(cpu)
+return "%s-%d-%X" % tuple(cpu)[:3]
def find_event(eventurl, model):
print >>sys.stderr, "Downloading", eventurl
@@ -81,7 +90,7 @@ def find_event(eventurl, model):
return found
if not args.all:
-cpu, model = get_cpu_str()
+cpu = get_cpu_str()
if not cpu:
sys.exit("Unknown CPU type")
@@ -94,7 +103,8 @@ for j in u:
n = j.rstrip().split(',')
if len(n) >= 4 and (args.all or n[0] == cpu) and n[3] == "core":
if args.all:
-vendor, fam, model = n[0].split("-")
+components = n[0].split("-")
+model = components[2]
model = int(model, 16)
cpufound += 1
found += find_event(baseurl + n[2], model)
@@ -146,7 +156,17 @@ case `egrep -q "^cpu family\s*: 6" /proc/cpuinfo &&
echo >&2 "Unknown CPU. Run contrib/gen_autofdo_event.py --all --script to
update script."
exit 1 ;;'''
print "esac"
-print 'exec perf record -e $E -b "$@"'
+print "set -x"
+print 'if ! perf record -e $E -b "$@" ; then'
+print ' # PEBS may not actually be working even if the processor supports
it'
+print ' # (e.g., in a virtual machine). Trying to run without /p.'
+print ' set +x'
+print ' echo >&2 "Retrying without /p."'
+print ' E="$(echo "${E}" | sed -e \'s/\/p/\//\')"'
+print ' set -x'
+print ' exec perf record -e $E -b "$@"'
+print ' set +x'
+print 'fi'
if cpufound == 0 and not args.all:
sys.exit('CPU %s not found' % cpu)
diff --git a/gcc/config/i386/gcc-auto-profile b/gcc/config/i386/gcc-auto-profile
index 5da5c63cd84..56f64cbff1f 100755
--- a/gcc/config/i386/gcc-auto-profile
+++ b/gcc/config/i386/gcc-auto-profile
@@ -1,7 +1,7 @@
#!/bin/sh
-# profile workload for gcc profile feedback (autofdo) using Linux perf
-# auto generated. to regenerate for new CPUs run
-# contrib/gen_autofdo_event.py --shell --all in gcc source
+# Profile workload for gcc profile feedback (autofdo) using Linux perf.
+# Auto generated. To regenerate for new CPUs run
+# contrib/gen_autofdo_event.py --script --all in gcc source
# usages:
# gcc-auto-profile program (profile program and children)
@@ -10,7 +10,7 @@
# gcc-auto-profile --kernel -a sleep X (profile kernel)
# gcc-auto-profile --all -a sleep X(profile kernel and user space)
-# identify branches taken event for CPU
+# Identify branches taken event for CPU.
#
FLAGS=u
@@ -37,7 +37,12 @@ case `egrep -q "^cpu family\s*: 6" /proc/cpuinfo &&
egrep "^model\s*:" /proc/cpuinfo | head -n1` in
model*:\ 55|\
model*:\ 77|\
-model*:\ 76) E="cpu/event=0xC4,umask=0xFE/p$FLAGS" ;;
+model*:\ 76|\
+model*:\ 92|\
