Em Tue, Jul 17, 2018 at 11:54:30AM +0300, Adrian Hunter escreveu: > On 06/06/18 16:19, Arnaldo Carvalho de Melo wrote: > > 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 <[email protected]> > >>> Acked-by: Andi Kleen <[email protected]> > >>> --- > >>> 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) <[email protected]> > > > > Thanks, giving it some more hours and will apply and try to test it. > > Any update on this?
On the post-vacation pile, will get to it. - Arnaldo
