Today I learned about the vDSO on the Linux man page: vdso(7) — Linux manual page. It’s a facility for replacing syscalls with normal user-space function calls for things like getting the time of day for better performance.
Found an old LWN article: Moving interrupts to threads.
Ordered on Amazon today:
- Understanding the Linux Kernel 3e: From I/O Ports to Process Management
- Linux Device Drivers 3e
- Linux Network Administrator’s Guide 3e
I’m not sure what to make of the fact that these books are nearly 20 years old… totally out of date, but all that is available? What’s up with that?
I think at this point I am ready to use iptables in anger for the first time in a long time, and the first time ever on a router.
However, before I take that on, I’m going to have a quick diversion into the following books, and then sleep, and I will do my iptables programming when I wake up tomorrow.
This a note for Future John: Using filesystem capabilities with rsync by Hazel Smith. Use the CAP_DAC_READ_SEARCH capability. AKA: how I learned to stop worrying and love CAP_DAC_READ_SEARCH. There are some more notes over on Linux Capabilities and rsync, from presentation to practice.
This was a fun read, about Linus and the early days of Linux: The early days of Linux. I didn’t know he was a gamer! But, I suppose, who isn’t? :)
Today I discovered: The Linux man-pages project.
I’m reading How Linux Works, 3rd Edition: What Every Superuser Should Know and I learned that you can force the kernel to reload a partition table with a command like this:
# blockdev --rereadpt /dev/sdX