On Mon, Sep 02, 2013 at 08:33:41PM +0800, Wanpeng Li wrote:
> 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 <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
> ---
> 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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