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authorChristoph Lameter <clameter@sgi.com>2008-04-28 05:12:40 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 11:58:21 -0400
commita10aa579878fc6f9cd17455067380bbdf1d53c91 (patch)
treec42fbb1e9422e5334c2207cafed4a2b5b1ad16c4 /fs/proc
parentb45445684198a946b587732265692e6495993abf (diff)
vmalloc: show vmalloced areas via /proc/vmallocinfo
Implement a new proc file that allows the display of the currently allocated vmalloc memory. It allows to see the users of vmalloc. That is important if vmalloc space is scarce (i386 for example). And it's going to be important for the compound page fallback to vmalloc. Many of the current users can be switched to use compound pages with fallback. This means that the number of users of vmalloc is reduced and page tables no longer necessary to access the memory. /proc/vmallocinfo allows to review how that reduction occurs. If memory becomes fragmented and larger order allocations are no longer possible then /proc/vmallocinfo allows to see which compound page allocations fell back to virtual compound pages. That is important for new users of virtual compound pages. Such as order 1 stack allocation etc that may fallback to virtual compound pages in the future. /proc/vmallocinfo permissions are made readable-only-by-root to avoid possible information leakage. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: CONFIG_MMU=n build fix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Arjan van de Ven <arjan@infradead.org> 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/proc_misc.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 2d563979cb02..441a32f0e5f2 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -456,6 +456,20 @@ static const struct file_operations proc_slabstats_operations = {
456#endif 456#endif
457#endif 457#endif
458 458
459#ifdef CONFIG_MMU
460static int vmalloc_open(struct inode *inode, struct file *file)
461{
462 return seq_open(file, &vmalloc_op);
463}
464
465static const struct file_operations proc_vmalloc_operations = {
466 .open = vmalloc_open,
467 .read = seq_read,
468 .llseek = seq_lseek,
469 .release = seq_release,
470};
471#endif
472
459static int show_stat(struct seq_file *p, void *v) 473static int show_stat(struct seq_file *p, void *v)
460{ 474{
461 int i; 475 int i;
@@ -869,6 +883,9 @@ void __init proc_misc_init(void)
869 create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations); 883 create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations);
870#endif 884#endif
871#endif 885#endif
886#ifdef CONFIG_MMU
887 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
888#endif
872 create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations); 889 create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
873 create_seq_entry("pagetypeinfo", S_IRUGO, &pagetypeinfo_file_ops); 890 create_seq_entry("pagetypeinfo", S_IRUGO, &pagetypeinfo_file_ops);
874 create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations); 891 create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations);