Messages in this thread | | | Date | Thu, 22 Dec 2005 15:53:52 -0800 (PST) | From | "Randy.Dunlap" <> | Subject | Re: [patch 0/9] mutex subsystem, -V4 |
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On Thu, 22 Dec 2005, Sean wrote:
> On Thu, December 22, 2005 6:34 pm, Christoph Hellwig said: > > On Thu, Dec 22, 2005 at 03:30:14PM -0800, Andrew Morton wrote: > >> No it does not. > >> > >> Ingo's work has shown us two things: > >> > >> a) semaphores use more kernel text than they should and > >> > >> b) semaphores are less efficient than they could be. > >> > >> Fine. Let's update the semaphore implementation to fix those things. > >> Nobody has addressed this code in several years. If we conclusively > >> cannot > >> fix these things then that's the time to start looking at implementing > >> new > >> locking mechanisms. > > > > c) semaphores are total overkill for 99% percent of the users. Remember > > this thing about optimizing for the common case? > > > > Pretty much everywhere we do want mutex semantic. So let's have a proper > > primitive exactly for that, and we can keep the current semaphore > > implementation (with a much simpler implementation) for that handfull of > > users in the kernel that really want a counting semaphore. > > > > I really don't get why you hate mutex primitives so much. > > > > Yes it's hard to figure. It seems to be deeper than just hating mutex > primitives, he hates the timer core updates that come from Ingo too; this > may be a general dislike for all things -rt.
Andrew can surely answer that, but it could be something as simple as wanting to build a more stable kernel (one without so much churn), so that things have time to mature and improve without breaking so many other things...
This (current) is a hectic development cycle style. -- ~Randy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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