Messages in this thread | | | Date | Tue, 2 Jun 2009 21:13:37 +0300 | Subject | Re: [benchmark] 1% performance overhead of paravirt_ops on native kernels | From | Pekka Enberg <> |
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Hi Chris,
On Tue, Jun 2, 2009 at 8:03 AM, Chris Mason <chris.mason@oracle.com> wrote: >>> The best place to fix xen is in the kernel.
On Tue, Jun 02, 2009 at 08:22:57AM -0700, Ulrich Drepper wrote: >> No. The best way to fix things is _on the way into the kernel_.
On Tue, Jun 2, 2009 at 7:20 PM, Chris Mason <chris.mason@oracle.com> wrote: > It all depends on which parts are causing problems. A 1% performance > hit, under a CONFIG_ that can be disabled? If maintainers are focusing > on details like this for long term and active projects, we're doing > something very wrong.
The fact that CONFIG_PARAVIRT can be disabled doesn't really help. As a matter of fact, I'd argue that one of the primary reasons CONFIG_SLUB regression is still there is because people can just disable it and use CONFIG_SLAB instead.
So I think we have some evidence to suggest that people have less incentive to fix things once something is merged to the kernel. And I don't mean the authors of the code here but basically _everyone_ involved in kernel development. It usually takes effort from variety of people to get everything ironed out because, lets face it, we can't expect a handful of people to test out every configuration let alone fix them.
Pekka -- 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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