Messages in this thread | | | Subject | Re: [RFC PATCH] Add /proc/<pid>/numa_vamaps for numa node information | From | "prakash.sangappa" <> | Date | Wed, 12 Sep 2018 13:57:49 -0700 |
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On 09/12/2018 01:42 PM, prakash.sangappa wrote: > > > On 05/09/2018 04:31 PM, Dave Hansen wrote: >> On 05/07/2018 06:16 PM, prakash.sangappa wrote: >>> It will be /proc/<pid>/numa_vamaps. Yes, the behavior will be >>> different with respect to seeking. Output will still be text and >>> the format will be same. >>> >>> I want to get feedback on this approach. >> I think it would be really great if you can write down a list of the >> things you actually want to accomplish. Dare I say: you need a >> requirements list. >> >> The numa_vamaps approach continues down the path of an ever-growing list >> of highly-specialized /proc/<pid> files. I don't think that is >> sustainable, even if it has been our trajectory for many years. >> >> Pagemap wasn't exactly a shining example of us getting new ABIs right, >> but it sounds like something along those is what we need. > > Just sent out a V2 patch. This patch simplifies the file content. It > only provides VA range to numa node id information. > > The requirement is basically observability for performance analysis. > > - Need to be able to determine VA range to numa node id information. > Which also gives an idea of which range has memory allocated. > > - The proc file /proc/<pid>/numa_vamaps is in text so it is easy to > directly view. > > The V2 patch supports seeking to a particular process VA from where > the application could read the VA to numa node id information. > > Also added the 'PTRACE_MODE_READ_REALCREDS' check when opening the > file /proc file as was indicated by Michal Hacko > I meant Michal Hocko Sorry misspelled the name.
> The VA range to numa node information from this file can be used by pmap. > > Here is a sample from a prototype change to pmap(procps) showing > numa node information, gathered from the new 'numa_vamaps' file. > > $ ./rpmap -L -A 00000000006f8000,00007f5f730fe000 31423|more > 31423: bash > 00000000006f8000 16K N1 rw--- bash > 00000000006fc000 4K N0 rw--- bash > 00000000006fd000 4K N0 rw--- [ anon ] > 00000000006fe000 8K N1 rw--- [ anon ] > 0000000000700000 4K N0 rw--- [ anon ] > 0000000000701000 4K N1 rw--- [ anon ] > 0000000000702000 4K N0 rw--- [ anon ] > 0000000000ce8000 52K N0 rw--- [ anon ] > 0000000000cf5000 4K N1 rw--- [ anon ] > 0000000000cf6000 28K N0 rw--- [ anon ] > 0000000000cfd000 4K N1 rw--- [ anon ] > 0000000000cfe000 28K N0 rw--- [ anon ] > 0000000000d05000 504K N1 rw--- [ anon ] > 0000000000d83000 8K N0 rw--- [ anon ] > 0000000000d85000 932K N1 rw--- [ anon ] > 0000000000e6e000 4K - rw--- [ anon ] > 0000000000e6f000 168K N1 rw--- [ anon ] > 00007f5f72ef4000 4K N2 r-x-- libnss_files-2.23.so > 00007f5f72ef5000 40K N0 r-x-- libnss_files-2.23.so > 00007f5f72eff000 2044K - ----- libnss_files-2.23.so > 00007f5f730fe000 4K N0 r---- libnss_files-2.23.so > total 3868K > > -Prakash.
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