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| author | Rafael Aquini <aquini@redhat.com> | 2015-02-12 15:01:08 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-12 18:54:12 -0800 |
| commit | 198d1597cc5a12d04af18b69338a5b1d66ee7020 (patch) | |
| tree | 79ae5755cf7f159bf16423fa1c01ac755641f36b /fs/proc | |
| parent | 0c3697118bb4f0991b11dafea038e4457813cae0 (diff) | |
| download | linux-198d1597cc5a12d04af18b69338a5b1d66ee7020.tar.bz2 | |
fs: proc: task_mmu: show page size in /proc/<pid>/numa_maps
The output of /proc/$pid/numa_maps is in terms of number of pages like
anon=22 or dirty=54. Here's some output:
7f4680000000 default file=/hugetlb/bigfile anon=50 dirty=50 N0=50
7f7659600000 default file=/anon_hugepage\040(deleted) anon=50 dirty=50 N0=50
7fff8d425000 default stack anon=50 dirty=50 N0=50
Looks like we have a stack and a couple of anonymous hugetlbfs
areas page which both use the same amount of memory. They don't.
The 'bigfile' uses 1GB pages and takes up ~50GB of space. The
anon_hugepage uses 2MB pages and takes up ~100MB of space while the stack
uses normal 4k pages. You can go over to smaps to figure out what the
page size _really_ is with KernelPageSize or MMUPageSize. But, I think
this is a pretty nasty and counterintuitive interface as it stands.
This patch introduces 'kernelpagesize_kB' line element to
/proc/<pid>/numa_maps report file in order to help identifying the size of
pages that are backing memory areas mapped by a given task. This is
specially useful to help differentiating between HUGE and GIGANTIC page
backed VMAs.
This patch is based on Dave Hansen's proposal and reviewer's follow-ups
taken from the following dicussion threads:
* https://lkml.org/lkml/2011/9/21/454
* https://lkml.org/lkml/2014/12/20/66
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/task_mmu.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 1359a911d194..956b75d61809 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1557,6 +1557,8 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid) for_each_node_state(nid, N_MEMORY) if (md->node[nid]) seq_printf(m, " N%d=%lu", nid, md->node[nid]); + + seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); out: seq_putc(m, '\n'); m_cache_vma(m, vma); |