Messages in this thread | | | Date | Mon, 21 Dec 2009 12:17:00 +0100 | From | Arjan van de Ven <> | Subject | Re: workqueue thing |
| |
On 12/21/2009 12:09, Andi Kleen wrote: > On Mon, Dec 21, 2009 at 10:17:54AM +0100, Jens Axboe wrote: >> On Fri, Dec 18 2009, Arjan van de Ven wrote: >>> in addition, threads are cheap. Linux has no technical problem with >>> running 100's of kernel threads (if not 1000s); they cost basically a >>> task struct and a stack (2 pages) each and that's about it. making an >>> elaborate-and-thus-fragile design to save a few kernel threads is >>> likely a bad design direction... >> >> One would hope not, since that is by no means outside of what you see on >> boxes today... Thousands. The fact that they are cheap, is not an >> argument against doing it right. Conceptually, I think the concurrency >> managed work queue pool is a much cleaner (and efficient) design. > > Agreed. Even if possible thousands of threads waste precious cache.
only used ones waste cache ;-)
> And they look ugly in ps.
that we could solve by making them properly threads of each other; ps and co already (at least by default) fold threads of the same program into one.
> > Also the nice thing about dynamically sizing the thread pool > is that if something bad (error condition that takes long) happens > in one work queue for a specific subsystem there's still a chance > to make process with other operations in the same subsystem.
yup same is true for hitting some form of contention; just make an extra thread so that the rest can continue.
| |