:While I am here, can the schedulers allow userspace to specify a cpumask :a thread is willing to run on, some highend software e.g database :systems may want this feature, as they are intend to manager their :CPU locality like they did for RAW device.
Hi, It is quite possible that I misunderstand something here, so I apologise if this is a stupid question, but: I thought one of the goals of DragonFlyBSD (one which from what I have read is very novel, and seems to make much logical sense) is that threads are not moved between CPUs, and that this is *UNLIKE* FreeBSD 5+ series which do allow threads to move between CPUs. That is the main use of LWKT and provides the ability for lockless algorithms to be used. Therefore, I guess what I do not understand is how giving a process a CPU mask that would allow it (e.g. on a quad core machine) to run on say two processors would then translate into the DFly model - does it mean that if the process has two LWPs, their associated kernel threads would be split between the CPUs under their respective LWKT shcedulers? Or am I somehow confusing kernel space and user space? How would a single process with a single associated LWP and thus kernel thread (which I believe have a 1:1 relationship) benefit from a CPU mask specifying two or more CPUs to process on? Sorry for taking up your time if what I said seems silly. Thanks for your patience, Alex J Burke.
