Messages in this thread | | | Date | Mon, 11 Nov 2013 22:10:02 +0100 | From | Ingo Molnar <> | Subject | Re: [tip:perf/core] tools/perf: Add required memory barriers |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Thu, Nov 07, 2013 at 09:21:22AM +0100, Ingo Molnar wrote: > > > > * Peter Zijlstra <peterz@infradead.org> wrote: > > > > > > Requiring the user of a kernel interface to have a deep knowledge of > > > > optimizing compilers, barriers, and CPU memory models is just asking > > > > for trouble. > > > > > > It shouldn't be all that hard to put this in a (lgpl) library others can > > > link to -- that way you can build it once (using GCC). > > > > I'd suggest to expose it via a new perf syscall, using vsyscall methods to > > not have to enter the kernel for the pure user-space bits. It should also > > have a real usecase in tools/perf/ so that it's constantly tested, with > > matching 'perf test' entries, etc. > > Oh man, I've never poked at the entire vsyscall stuff before; let alone > done it for ARM, ARM64, PPC64 etc.. > > Keeping it in userspace like we have is so much easier.
... and so much more broken in fantastic ways, right? ;-)
Thanks,
Ingo
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