Messages in this thread | | | Date | Tue, 17 Feb 2009 10:43:59 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 2/4] generic-smp: remove kmalloc usage |
| |
* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> On Mon, 2009-02-16 at 16:40 -0800, Linus Torvalds wrote: > > > > On Mon, 16 Feb 2009, Peter Zijlstra wrote: > > > > > > Now that there is no strict need for kmalloc anymore, and nobody seems to > > > rely it for the queueing behaviour, remove it. > > > > Peter, I really hate this series. > > > > Why? > > > > In 1/4 you introduce that cfd RCU thing, and then in 2/4 you remove it > > again. > > Ah, no, I don't actually. I remove the kmalloc+call_rcu stuff in 2, not > the newly cfd mini rcu thing. > > > I realize that you seem to do that in order to do some incremental > > step-wise changes, but quite frankly, it just complicates the whole series > > and makes the patches much harder to read and follow. > > > > Why don't you just combine patches 1&2? That split-up seems to just > > confuse things. At least it confuses me. Why does it happen? > > The idea was to remove the necessity for kmalloc() in patch 1, > and then remove kmalloc() in patch 2. > > If you prefer I can fold them, no problem. > > But as you might have seen, Oleg has been punching holes in my > #1, so I guess I'm back to the drawing board no matter what > :-)
I think the kmalloc() is clearly ugly, we should remove it, and if someone wants to add it we want to see _hard numbers_ that it's worth the ugliness. I.e. lets go with the two patches i posted, they are obvious and tested.
We should not bend backwards trying to preserve that kmalloc() [and prove that it's safe and race-free] - i.e. the burden of proof is on the person insisting that it's needed, not on the person wanting to remove it.
Ingo
| |