hi Naoya, On 2017/2/23 11:23, Naoya Horiguchi wrote: > On Mon, Feb 20, 2017 at 05:00:17AM +0000, Horiguchi Naoya(堀口 直也) wrote: >> On Tue, Feb 14, 2017 at 04:41:29PM +0100, Jan Stancek wrote: >>> Hi, >>> >>> code below (and LTP madvise07 [1]) doesn't produce SIGBUS, >>> unless I touch/prefault page before call to madvise(). >>> >>> Is this expected behavior? >> >> Thank you for reporting. >> >> madvise(MADV_HWPOISON) triggers page fault when called on the address >> over which no page is faulted-in, so I think that SIGBUS should be >> called in such case. >> >> But it seems that memory error handler considers such a page as "reserved >> kernel page" and recovery action fails (see below.) >> >> [ 383.371372] Injecting memory failure for page 0x1f10 at 0x7efcdc569000 >> [ 383.375678] Memory failure: 0x1f10: reserved kernel page still referenced by 1 users >> [ 383.377570] Memory failure: 0x1f10: recovery action for reserved kernel page: Failed >> >> I'm not sure how/when this behavior was introduced, so I try to understand. > > I found that this is a zero page, which is not recoverable for memory > error now. > >> IMO, the test code below looks valid to me, so no need to change. > > I think that what the testcase effectively does is to test whether memory > handling on zero pages works or not. > And the testcase's failure seems acceptable, because it's simply not-implemented yet. > Maybe recovering from error on zero page is possible (because there's no data > loss for memory error,) but I'm not sure that code might be simple enough and/or > it's worth doing ... I question about it, if a memory error happened on zero page, it will cause all of data read from zero page is error, I mean no-zero, right? And can we just use re-initial it with zero data maybe by memset ? Thanks Yisheng Xie. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
