To modify kernel parameters for improving CPU performance, which command would you use?

The command used to modify kernel parameters for improving CPU performance is sysctl. This command interacts with the Linux kernel's parameters, allowing users to view and adjust settings related to system performance, including CPU management. It provides a straightforward way to tune various kernel settings on-the-fly without needing to reboot the system, making it a robust tool for performance optimization.

Sysctl reads and writes parameters from the /proc/sys directory, where many of the kernel's parameters are exposed, including those affecting CPU performance, memory management, and networking. Users can implement changes either temporarily (until the next reboot) or permanently by making entries in the /etc/sysctl.conf file or other configuration files in the /etc/sysctl.d/ directory.

The other options provided do not specifically focus on kernel parameter modification for CPU performance. Modprobe is used to add or remove modules from the Linux kernel, while setconfig does not exist in the standard Linux commands, and tune2fs is a utility for adjusting filesystem parameters on ext2/ext3/ext4 filesystems. Thus, sysctl is precisely the tool designed for handling kernel parameter modifications.