Messages in this thread | | | Date | Sat, 6 Aug 2022 10:59:03 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v3] x86,mm: print likely CPU at segfault time |
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* Ingo Molnar <mingo@kernel.org> wrote:
> > instrumentation_begin(); > > - handle_page_fault(regs, error_code, address); > > + handle_page_fault(regs, error_code, address, cpu); > > Not convinced that this is a good change: this will bloat all the > affected code by a couple of dozen instructions - for no good reason in > the context of this patch. > > Boris, why should we do this? Extracting a parameter at higher levels and > passing it down to lower levels is almost always a bad idea from a code > generation POV, unless the majority of lower levels needs this > information anyway (which isn't the case here).
Oh, I just got to this series in my mbox:
[RFC PATCH 0/5] Print CPU at segfault time ... [RFC PATCH 5/5] x86/entry: Store CPU info on exception entry
With that basis, printing the segfault CPU becomes a 'free' feature.
At the cost of putting ~2 new instructions into the hotpath of every exception though. :-/
Thanks,
Ingo
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