For analysis purpose it is useful to have numa node information corresponding mapped virtual address ranges of a process. Currently, the file /proc/<pid>/numa_maps provides list of numa nodes from where pages are allocated per VMA of a 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. The format of /proc/<pid>/numa_maps file content is dependent on /proc/<pid>/maps file content as mentioned in the manpage. i.e one line entry for every VMA corresponding to entries in /proc/<pids>/maps file. Therefore changing the output of /proc/<pid>/numa_maps may not be possible. This patch set introduces the file /proc/<pid>/numa_vamaps which will provide proper break down of VA ranges by numa node id from where the mapped pages are allocated. For Address ranges not having any pages mapped, a '-' is printed instead of numa node id. Includes support to lseek, allowing seeking to a specific process Virtual address(VA) starting from where the address range to numa node information can to be read from this file. The new file /proc/<pid>/numa_vamaps will be governed by ptrace access mode PTRACE_MODE_READ_REALCREDS. See following for previous discussion about this proposal https://marc.info/?t=152524073400001&r=1&w=2 Prakash Sangappa (6): Add check to match numa node id when gathering pte stats Add /proc/<pid>/numa_vamaps file for numa node information Provide process address range to numa node id mapping Add support to lseek /proc/<pid>/numa_vamaps file File /proc/<pid>/numa_vamaps access needs PTRACE_MODE_READ_REALCREDS check /proc/pid/numa_vamaps: document in Documentation/filesystems/proc.txt Documentation/filesystems/proc.txt | 21 +++ fs/proc/base.c | 6 +- fs/proc/internal.h | 1 + fs/proc/task_mmu.c | 265 ++++++++++++++++++++++++++++++++++++- 4 files changed, 285 insertions(+), 8 deletions(-) -- 2.7.4
