On Thu 03-05-18 15:39:49, prakash.sangappa wrote: > > > On 05/03/2018 11:03 AM, Christopher Lameter wrote: > > On Tue, 1 May 2018, Prakash Sangappa wrote: > > > > > For analysis purpose it is useful to have numa node information > > > corresponding mapped address ranges of the process. Currently > > > /proc/<pid>/numa_maps provides list of numa nodes from where pages are > > > allocated per VMA of the process. This is not useful if an user needs to > > > determine which numa node the mapped pages are allocated from for a > > > particular address range. It would have helped if the numa node information > > > presented in /proc/<pid>/numa_maps was broken down by VA ranges showing the > > > exact numa node from where the pages have been allocated. > > Cant you write a small script that scans the information in numa_maps and > > then displays the total pages per NUMA node and then a list of which > > ranges have how many pages on a particular node? > > Don't think we can determine which numa node a given user process > address range has pages from, based on the existing 'numa_maps' file. yes we have. See move_pages... > > > reading this file will not be restricted(i.e requiring CAP_SYS_ADMIN). > > So a prime motivator here is security restricted access to numa_maps? > No it is the opposite. A regular user should be able to determine > numa node information. Well, that breaks the layout randomization, doesn't it? -- Michal Hocko SUSE Labs
