On Fri, 06 Apr 2007 18:38:40 -0400 Jeff Garzik <[EMAIL PROTECTED]> wrote:
> Robin Holt wrote: > > We have been testing a new larger configuration and we are seeing a very > > large scan time of init's tsk->children list. In the cases we are seeing, > > there are numerous kernel processes created for each cpu (ie: events/0 > > ... events/<big number>, xfslogd/0 ... xfslogd/<big number>). These are > > all on the list ahead of the processes we are currently trying to reap. > > What about attacking the explosion of kernel threads? > > As CPU counts increase, the number of per-CPU kernel threads gets really > ridiculous. > > I would rather change the implementation under the hood to start per-CPU > threads on demand, similar to a thread-pool implementation. > > Boxes with $BigNum CPUs probably won't ever use half of those threads. I suspect there are quite a few kernel threads which don't really need to be threads at all: the code would quite happily work if it was changed to use keventd, via schedule_work() and friends. But kernel threads are somewhat easier to code for. I also suspect that there are a number of workqueue threads which could/should have used create_singlethread_workqueue(). Often this is because the developer just didn't think to do it. otoh, a lot of these inefficeincies are probably down in scruffy drivers rather than in core or top-level code. <I also wonder where all these parented-by-init, presumably-not-using-kthread kernel threads are coming from> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/