Messages in this thread | | | Date | Wed, 6 Jun 2018 10:19:46 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH V4 3/3] x86: Add entry trampolines to kcore |
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Em Wed, Jun 06, 2018 at 03:16:31PM +0200, Peter Zijlstra escreveu: > On Wed, Jun 06, 2018 at 03:54:11PM +0300, Adrian Hunter wrote: > > Without program headers for PTI entry trampoline pages, the trampoline > > virtual addresses do not map to anything. > > > > > > > In addition, entry trampolines all map to the same page. Represent that by > > giving the corresponding program headers in kcore the same offset. > > > > This has the benefit that, when perf tools uses /proc/kcore as a source for > > kernel object code, samples from different CPU trampolines are aggregated > > together. Note, such aggregation is normal for profiling i.e. people want > > to profile the object code, not every different virtual address the object > > code might be mapped to (across different processes for example). > > > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > > Acked-by: Andi Kleen <ak@linux.intel.com> > > --- > > arch/x86/mm/cpu_entry_area.c | 10 ++++++++++ > > fs/proc/kcore.c | 7 +++++-- > > include/linux/kcore.h | 13 +++++++++++++ > > 3 files changed, 28 insertions(+), 2 deletions(-) > > This also adds the KCORE_REMAP functionality, but isn't mentioned at all > in the Changelog. > > Still, looks OK I suppose,
I can add a note about that,
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Thanks, giving it some more hours and will apply and try to test it.
- Arnaldo
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