mm/page_owner.c: remove unnecessary stack_trace field
Page owner uses the page_ext structure to keep meta-information for every
page in the system. The structure also contains a field of type 'struct
stack_trace', page owner uses this field during invocation of the function
save_stack_trace. It is easy to notice that keeping a copy of this
structure for every page in the system is very inefficiently in terms of
memory.
The patch removes this unnecessary field of page_ext and forces page owner
to use a stack_trace structure allocated on the stack.
[akpm@linux-foundation.org: use struct initializers]
Signed-off-by: Sergei Rogachev <rogachevsergei@gmail.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index d2a2c84..c42981c 100644
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -40,7 +40,7 @@
#ifdef CONFIG_PAGE_OWNER
unsigned int order;
gfp_t gfp_mask;
- struct stack_trace trace;
+ unsigned int nr_entries;
unsigned long trace_entries[8];
#endif
};