> On Thursday 31 August 2017 10:13 PM, Arnaldo Carvalho de Melo wrote: > Em Tue, Aug 29, 2017 at 01:45:53PM +0200, Peter Zijlstra escreveu: > On Tue, Aug 29, 2017 at 05:05:15PM +0530, Madhavan Srinivasan wrote: > > > On Tuesday 29 August 2017 06:22 AM, [email protected] wrote: > From: Kan Liang <[email protected]> > > For understanding how the workload maps to memory channels and > hardware > behavior, it's very important to collect address maps with physical > addresses. For example, 3D XPoint access can only be found by filtering > the physical address. > > Add a new sample type for physical address. > > perf already has a facility to collect data virtual address. This patch > introduces a function to convert the virtual address to physical address. > The function is quite generic and can be extended to any architecture as > long as a virtual address is provided. > - For kernel direct mapping addresses, virt_to_phys is used to convert > the virtual addresses to physical address. > - For user virtual addresses, __get_user_pages_fast is used to walk the > pages tables for user physical address. > - This does not work for vmalloc addresses right now. These are not > resolved, but code to do that could be added. > > The new sample type requires collecting the virtual address. The > virtual address will not be output unless SAMPLE_ADDR is applied. > > For security, the physical address can only be exposed to root or > privileged user. > > Tested-by: Madhavan Srinivasan <[email protected]> > > You mean you tested this together with Kan's v2 perf tools patches? If > that is so I'll add this tested-by to those patches, ok? > Arnaldo, > > No. Kernel side patch showed the link for the v1 of the perf tool side > patchset (5 patch series) and I used that to test. >
Thanks Maddy for the test. Yes, the kernel patch went with user tool v1 version. The user tool v2 version did a little modification according to the final kernel patch. The only difference is not to mandate SAMPLE_ADDR when SAMPLE_PHYS_ADDR. Thanks, Kan > > >This patch is kernel patch. > >The user space patch can be found here. > >https://urldefense.proofpoint.com/v2/url?u=https- > 3A__www.spinics.net_lists_kernel_msg2587093.html&d=DwIBaQ&c=jf_iaSHv > JObTbx-siA1ZOg&r=3f2W2m24mqGnx1C8qDsVjM_Sd89MwbaDB37IJVL- > h7w&m=bL7qsJKf8aRpvBVr07ODZxoQhPgxffpGFgN9A4iyACw&s=R1OMYJt1sz > qNhPZu8QQDDRCnQgHZiQzcCPzofF6FIF8&e= > > Maddy > > > > Thanks maddy! >
