lscpu: optimize query virt pci device
The lscpu command needs to traverse the /proc/bus/pci/devices file
three times to check for any PCI devices related to virtualization.
If there are many PCI devices on the machine, this can lead to
increased execution time for lscpu. It would be beneficial to
consolidate these queries into a single check to optimize the
execution time of lscpu.
Use time command to test on a machine with 13000 PCI devices:
before:
real 0m13.506s
user 0m0.028s
sys 0m13.409s
after:
real 0m5.834s
user 0m0.018s
sys 0m5.771s
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Gbp-Pq: Topic upstream-master
Gbp-Pq: Name lscpu-optimize-query-virt-pci-device.patch