Printk Improvement For Linux 6.19 Can Significantly Speed-Up Boot Times For Some Systems
The Linux kernel's printk code for logging kernel messages has some useful improvements with the Linux 6.19 kernel.
First up is the possibility to "significantly" speed up the Linux boot process for some systems by releasing the console lock between reach record in the KThread used for legacy consoles on real-time (RT) kernels. If you are using a legacy console on a Linux RT system, the boot time can be much better with Linux 6.19.
The change to release the console lock between printing records in the legacy thread was written by Andrew Murray. In testing on a PocketBeagle 2 device, he found significant speed-ups: dropping from 145 seconds to just 7.2 seconds!
Another notable change for printk in Linux 6.19 is allowing to create non-blocking console "NBCON" drivers with an unsafe write atomic callback. This is being used by an experimental NBCON netconsole driver that has yet to be mainlined. This experimental effort allows for the netconsole driver to enjoy threaded and atomic printing while netconsole itself doesn't support atomic operations.
The printk pull also adds support for NBCON consoles into the KDB kernel debugging code and various other enhancements.
First up is the possibility to "significantly" speed up the Linux boot process for some systems by releasing the console lock between reach record in the KThread used for legacy consoles on real-time (RT) kernels. If you are using a legacy console on a Linux RT system, the boot time can be much better with Linux 6.19.
The change to release the console lock between printing records in the legacy thread was written by Andrew Murray. In testing on a PocketBeagle 2 device, he found significant speed-ups: dropping from 145 seconds to just 7.2 seconds!
👁 printk improvement benchmark
Another notable change for printk in Linux 6.19 is allowing to create non-blocking console "NBCON" drivers with an unsafe write atomic callback. This is being used by an experimental NBCON netconsole driver that has yet to be mainlined. This experimental effort allows for the netconsole driver to enjoy threaded and atomic printing while netconsole itself doesn't support atomic operations.
The printk pull also adds support for NBCON consoles into the KDB kernel debugging code and various other enhancements.