Re: [PATCH 0/4] perf: add support for profiling jitted code

From: David Ahern
Date: Wed Feb 11 2015 - 11:25:16 EST


On 2/11/15 9:15 AM, Peter Zijlstra wrote:
On Wed, Feb 11, 2015 at 08:18:37AM -0500, Stephane Eranian wrote:

But, we need a portable solution, there are jitted environment on other
architectures.

Yeah, I'm aware of that. But the time people are not liking any of those
patches.

The thing that seems to have most traction is something like

lkml.kernel.org/r/20150211161256.GH2896@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Which would basically make the trace clock be CLOCK_MONOTONIC.


Sure, but IF that solution is ever adopted it will apply to top of tree kernels. In the meantime users of long term kernels (enterprise, LTS, other) need to be able to use this feature.

I understand that Ingo (and probably you as well) have a disdain for the kernel module approach mentioned above and it is not the preferred approach. But given the resistance for over *4 years* to solutions to this problem the module does provide a solution for the existing user base.

David
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