madvise_hwpoison won't check if the page is small page or huge page and 
traverse 
in small page granularity against the range unconditional, which result in a 
printk 
flood "MCE xxx: already hardware poisoned" if the page is huge page. This patch 
fix 
it by increase compound_order(compound_head(page)) for huge page iterator.

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 3
#define PAGE_SIZE       4096 * 512

int main(void)
{
        char *mem;
        int i;

        mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
                        PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | 
MAP_HUGETLB, 0, 0);

        if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
                return -1;
        
        munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

        return 0;
}

Signed-off-by: Wanpeng Li <liw...@linux.vnet.ibm.com>
---
 mm/madvise.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index 6975bc8..539eeb9 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -343,10 +343,11 @@ static long madvise_remove(struct vm_area_struct *vma,
  */
 static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end)
 {
+       struct page *p;
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
-       for (; start < end; start += PAGE_SIZE) {
-               struct page *p;
+       for (; start < end; start += PAGE_SIZE <<
+                               compound_order(compound_head(p))) {
                int ret;
 
                ret = get_user_pages_fast(start, 1, 0, &p);
-- 
1.8.1.2

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