----- Original Message ----- > From: "Hugh Dickins" <hughd@xxxxxxxxxx> > To: "Shaohua Li" <shli@xxxxxxxxxx> > Cc: "CAI Qian" <caiqian@xxxxxxxxxx>, "linux-mm" <linux-mm@xxxxxxxxx>, "linux-kernel" <linux-kernel@xxxxxxxxxxxxxxx>, > "Rik van Riel" <riel@xxxxxxxxxx>, "Sasha Levin" <sasha.levin@xxxxxxxxxx>, "Andrew Morton" > <akpm@xxxxxxxxxxxxxxxxxxxx>, "Linus Torvalds" <torvalds@xxxxxxxxxxxxxxxxxxxx> > Sent: Friday, March 8, 2013 2:49:48 AM > Subject: Re: change of behavior for madvise in 3.9-rc1 > > On Thu, 7 Mar 2013, Shaohua Li wrote: > > On Wed, Mar 06, 2013 at 11:05:04PM -0500, CAI Qian wrote: > > > Bisecting indicated that this commit, > > > 1998cc048901109a29924380b8e91bc049b32951 > > > mm: make madvise(MADV_WILLNEED) support swap file prefetch > > > > > > Caused an LTP test failure, > > > http://goo.gl/1FVPy > > > > > > madvise02 1 TPASS : failed as expected: > > > TEST_ERRNO=EINVAL(22): Invalid argument > > > madvise02 2 TPASS : failed as expected: > > > TEST_ERRNO=EINVAL(22): Invalid argument > > > madvise02 3 TPASS : failed as expected: > > > TEST_ERRNO=EINVAL(22): Invalid argument > > > madvise02 4 TPASS : failed as expected: > > > TEST_ERRNO=ENOMEM(12): Cannot allocate memory > > > madvise02 5 TFAIL : madvise succeeded unexpectedly > > > > > > While it passed without the above commit > > > madvise02 1 TPASS : failed as expected: > > > TEST_ERRNO=EINVAL(22): Invalid argument > > > madvise02 2 TPASS : failed as expected: > > > TEST_ERRNO=EINVAL(22): Invalid argument > > > madvise02 3 TPASS : failed as expected: > > > TEST_ERRNO=EINVAL(22): Invalid argument > > > madvise02 4 TPASS : failed as expected: > > > TEST_ERRNO=ENOMEM(12): Cannot allocate memory > > > madvise02 5 TPASS : failed as expected: > > > TEST_ERRNO=EBADF(9): Bad file descriptor > > > > I thought this is expected behavior. madvise(MADV_WILLNEED) to > > anonymous memory > > doesn't return -EBADF now, as now we support swap prefretch. > > I agree with Shaohua: although the kernel strives for > back-compatibility > with userspace, I don't think that goes so far as to tell an > arbitrary LTP > test that it has failed, once the kernel has been enhanced to support > new > functionality. We could never add or extend system calls if that > were so. Thanks for looking this. We will try to fix the LTP test instead. > > Hugh > -- 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>