From: "prakash.sangappa" <prakash.sangappa@oracle.com>
To: Dave Hansen <dave.hansen@intel.com>,
Anshuman Khandual <khandual@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-api@vger.kernel.org, mhocko@suse.com,
kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com,
drepper@gmail.com, rientjes@google.com,
Naoya Horiguchi <nao.horiguchi@gmail.com>,
Steven Sistare <steven.sistare@oracle.com>
Subject: Re: [RFC PATCH] Add /proc/<pid>/numa_vamaps for numa node information
Date: Wed, 12 Sep 2018 13:42:34 -0700 [thread overview]
Message-ID: <94ee0b6c-4663-0705-d4a8-c50342f6b483@oracle.com> (raw)
In-Reply-To: <aaca3180-7510-c008-3e12-8bbe92344ef4@intel.com>
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
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.
next prev parent reply other threads:[~2018-09-12 20:43 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-02 5:58 [RFC PATCH] Add /proc/<pid>/numa_vamaps for numa node information Prakash Sangappa
2018-05-02 21:33 ` Andrew Morton
2018-05-02 22:28 ` Dave Hansen
2018-05-02 23:17 ` prakash.sangappa
2018-05-03 8:46 ` Anshuman Khandual
2018-05-03 22:27 ` prakash.sangappa
2018-05-03 22:26 ` Dave Hansen
2018-05-07 23:22 ` prakash.sangappa
2018-05-08 0:05 ` Dave Hansen
2018-05-08 1:16 ` prakash.sangappa
2018-05-09 23:31 ` Dave Hansen
2018-09-12 20:42 ` prakash.sangappa [this message]
2018-09-12 20:57 ` prakash.sangappa
2018-09-14 1:33 ` Jann Horn
2018-09-14 6:21 ` Michal Hocko
2018-09-14 12:49 ` Jann Horn
2018-09-14 13:49 ` Michal Hocko
2018-09-14 18:07 ` Prakash Sangappa
2018-09-14 18:14 ` Jann Horn
2018-05-02 23:43 ` prakash.sangappa
2018-05-03 8:57 ` Michal Hocko
2018-05-03 22:37 ` prakash.sangappa
2018-05-04 11:10 ` Michal Hocko
2018-05-03 18:03 ` Christopher Lameter
2018-05-03 22:39 ` prakash.sangappa
2018-05-04 11:12 ` Michal Hocko
2018-05-04 16:18 ` Prakash Sangappa
2018-05-10 7:42 ` Michal Hocko
2018-05-10 16:00 ` Prakash Sangappa
2018-05-11 6:39 ` Michal Hocko
2018-05-04 14:57 ` Christopher Lameter
2018-05-04 16:27 ` Prakash Sangappa
2018-05-07 14:47 ` Christopher Lameter
2018-05-07 22:50 ` prakash.sangappa
2018-05-08 12:53 ` Christopher Lameter
2018-09-12 23:02 Alexey Dobriyan
2018-09-13 22:17 ` prakash.sangappa
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