From 198d1597cc5a12d04af18b69338a5b1d66ee7020 Mon Sep 17 00:00:00 2001 From: Rafael Aquini Date: Thu, 12 Feb 2015 15:01:08 -0800 Subject: fs: proc: task_mmu: show page size in /proc//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//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 Cc: Johannes Weiner Cc: Dave Hansen Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/proc/task_mmu.c') 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); -- cgit v1.2.3-59-g8ed1b