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pmbootstrap/pmb/parse/cpuinfo.py
yarl 864469531c
pmbootstrap qemu: add aarch64 big/little hack (MR 1983)
Workaround for qemu failing with:
  kvm_arm_vcpu_init failed: invalid argument.

Related: https://bugs.linaro.org/show_bug.cgi?id=1443
2020-10-20 22:34:08 +02:00

32 lines
997 B
Python

# Copyright 2020 Lary Gibaud
# SPDX-License-Identifier: GPL-3.0-or-later
import re
def arm_big_little_first_group_ncpus():
"""
Infer from /proc/cpuinfo on aarch64 if this is a big/little architecture
(if there is different processor models) and the number of cores in the
first model group.
https://en.wikipedia.org/wiki/ARM_big.LITTLE
:returns: the number of cores of the first model in the order given by
linux or None if not big/little architecture
"""
pattern = re.compile(r"^CPU part\s*: (\w+)$")
counter = 0
part = None
with open('/proc/cpuinfo', 'r') as cpuinfo:
for line in cpuinfo:
match = pattern.match(line)
if match:
grp = match.group(1)
if not part:
part = grp
counter += 1
elif part == grp:
counter += 1
else:
return counter
return None