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authorRafael Aquini <aquini@redhat.com>2015-02-12 15:01:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-12 18:54:12 -0800
commit198d1597cc5a12d04af18b69338a5b1d66ee7020 (patch)
tree79ae5755cf7f159bf16423fa1c01ac755641f36b /fs/proc
parent0c3697118bb4f0991b11dafea038e4457813cae0 (diff)
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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.c2
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);