Messages in this thread |  | | | Subject | Re: [patch 9/11] net: dst_entry.refcount, use, lastuse to use alloc_percpu | | From | Rusty Russell <> | | Date | Wed, 14 Sep 2005 17:21:02 +1000 |
On Tue, 2005-09-13 at 16:27 -0700, David S. Miller wrote: > From: Ravikiran G Thirumalai <kiran@scalex86.org> > Date: Tue, 13 Sep 2005 16:17:17 -0700 > > > But even 1 Million dst cache entries would be 16+4 MB additional for > > a 4 cpu box....is that too much? > > Absolutely. > > Per-cpu counters are great for things like single instance > statistics et al. But once you start doing them per-object > that's out of control bloat as far as I'm concerned.
This is why my original per-cpu allocator patch was damn slow, and GFP_KERNEL only. I wasn't convinced that high-churn objects are a good fit for spreading across cpus.
I thought that net devices and modules (which uses a primitive hard-coded "bigref" currently) were a fair uses for bigrefs, though I'd like to see some stats.
Cheers, Rusty. -- A bad analogy is like a leaky screwdriver -- Richard Braakman
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