Messages in this thread | | | Date | Wed, 21 Jan 2009 11:05:07 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] percpu: add optimized generic percpu accessors |
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* Tejun Heo <tj@kernel.org> wrote:
> Ingo Molnar wrote: > > The larger point still remains: the kernel dominantly uses static percpu > > variables by a margin of 10 to 1, so we cannot just brush away the static > > percpu variables and must concentrate on optimizing that side with > > priority. It's nice if the dynamic percpu-alloc side improves as well, of > > course. > > Well, the infrequent usage of dynamic percpu allocation is in some part > due to the poor implementation, so it's sort of chicken and egg problem. > I got into this percpu thing because I wanted a percpu reference count > which can be dynamically allocated and it sucked.
Sure, but even static percpu sucked very much (it expanded to half a dozen or more instructions), and dynamic is _more_ complex. Anyway, it's getting fixed now :-)
Ingo
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