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authorDavid Rientjes <rientjes@google.com>2013-04-30 02:06:11 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-30 02:54:28 +0400
commit4b59e6c4730978679b414a8da61514a2518da512 (patch)
tree241f48acea764191a458c6ae2d058b079b24f12d /lib
parentfe0bfaaff84429a35e4447d4ccd646aecf5999fb (diff)
downloadlinux-4b59e6c4730978679b414a8da61514a2518da512.tar.xz
mm, show_mem: suppress page counts in non-blockable contexts
On large systems with a lot of memory, walking all RAM to determine page types may take a half second or even more. In non-blockable contexts, the page allocator will emit a page allocation failure warning unless __GFP_NOWARN is specified. In such contexts, irqs are typically disabled and such a lengthy delay may even result in NMI watchdog timeouts. To fix this, suppress the page walk in such contexts when printing the page allocation failure warning. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/show_mem.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/lib/show_mem.c b/lib/show_mem.c
index 4407f8c9b1f7..b7c72311ad0c 100644
--- a/lib/show_mem.c
+++ b/lib/show_mem.c
@@ -18,6 +18,9 @@ void show_mem(unsigned int filter)
printk("Mem-Info:\n");
show_free_areas(filter);
+ if (filter & SHOW_MEM_FILTER_PAGE_COUNT)
+ return;
+
for_each_online_pgdat(pgdat) {
unsigned long i, flags;