[LTP] [PATCH v3] move_pages12: handle errno EBUSY for madvise(..., MADV_SOFT_OFFLINE)

[Richard Palethorpe]

Hello,

Li Wang <liwang@redhat.com> writes:

>
> Can you help to check if these commits have been backported to SLEL
> kernel-5.12?
>     commit e66f17ff71772b209eed39de35aaa99ba819c93d
>     commit c9d398fa237882ea07167e23bcfc5e6847066518
>     commit 4643d67e8cb0b3536ef0ab5cddd1cedc73fa14ad

The final one has not been backported yet, but I don't think we are
hitting that bug (there is a high chance I am wrong ofcourse). Thanks.

>
> The move_pages12 test actually found three regression BUG which has all
> been fixed in the mainline kernel so far.

It is a good test!

>
>
>> TBH I'm not sure what we are testing when checking the return value of
>> MADV_SOFT_OFFLINE? The bug is not reproduced if madvise always fails, so
>> the test should pass right?
>>
>
> The return value checking of MADV_SOFT_OFFLINE are two:
>     EINVAL - To make sure system support MADV_SOFT_OFFLINE
>     EBUSY -  To make ignore the defect(EBUSY when soft-offlining hugepage)
> designed by the kernel
>
> The madvise(MADV_SOFT_OFFLINE) should not always fail, it might get failure
> occasionally on EBUSY(ignored already), but exit with TCONF if hit EINVAL.
>
> @MIke & @Naoyo, If I was wrong please correct me.



-- 
Thank you,
Richard.