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authorChristoph Lameter <clameter@sgi.com>2008-04-28 02:12:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 08:58:21 -0700
commita10aa579878fc6f9cd17455067380bbdf1d53c91 (patch)
treec42fbb1e9422e5334c2207cafed4a2b5b1ad16c4 /include/linux/vmalloc.h
parentb45445684198a946b587732265692e6495993abf (diff)
downloadop-kernel-dev-a10aa579878fc6f9cd17455067380bbdf1d53c91.zip
op-kernel-dev-a10aa579878fc6f9cd17455067380bbdf1d53c91.tar.gz
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 'include/linux/vmalloc.h')
-rw-r--r--include/linux/vmalloc.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index ce8e7da..7f3adfd 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -87,4 +87,6 @@ extern void free_vm_area(struct vm_struct *area);
extern rwlock_t vmlist_lock;
extern struct vm_struct *vmlist;
+extern const struct seq_operations vmalloc_op;
+
#endif /* _LINUX_VMALLOC_H */
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