Archive for April, 2007

hammering lock structures

Monday, April 23rd, 2007

In the past days I worked on a fix for lock sizes mismatching between userspace/kernelspace which reveleated a very hard way.

Basically, lock_init() is called very early in the bootstrap code and a simple counter revealed that 8165 locks (FreeBSD-ia32, WITNESS, LOCK_PROFILING, INVARIANTS, DDB enabled) are initialized before that VM is set up and ready for working so we should have a very huge pool of pre-allocated external objects to be used in debugging kernel. The lock-free allocator (in a first moment extracting from the pool and when VM is ready fork working using malloc) is quite ready.

For the moment I want to better study and tuning an appropriate value for that pool.

Hello World

Sunday, April 15th, 2007

Hello guys,

I’m Attilio and I will work on improving lockmgr kernel syncronization primitives for this summer.

If you want to know more about lockmgr, please check for your manpage and possibly for the kernel code, located in sys/kern/kern_lock.c and sys/sys/lockmgr.h, so if you have any ideas, comments, feedbacks, just let me know.

That’s all for tonight.