Commit 629d9d1c authored Jan 18, 2016 by Arnd Bergmann Committed by Linus Torvalds Jan 20, 2016

mm: avoid uninitialized variable in tracepoint



A newly added tracepoint in the hugepage code uses a variable in the
error handling that is not initialized at that point:

include/trace/events/huge_memory.h:81:230: error: 'isolated' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The result is relatively harmless, as the trace data will in rare
cases contain incorrect data.

This works around the problem by adding an explicit initialization.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 7d2eba05 ("mm: add tracepoint for scanning pages")
Reviewed-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 2b4015e9

mm/huge_memory.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2320,7 +2320,7 @@ static void collapse_huge_page(struct mm_struct *mm,
		pgtable_t pgtable;
		struct page *new_page;
		spinlock_t pmd_ptl, pte_ptl;
		int isolated, result = 0;
		int isolated = 0, result = 0;
		unsigned long hstart, hend;
		struct mem_cgroup *memcg;
		unsigned long mmun_start; /* For mmu_notifiers */

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