On Wed, 26 Jul 2023 06:59:20 +0000 Andrew Yang (楊智強) <Andrew.Yang@xxxxxxxxxxxx> wrote: > > Have you observed issues in real life? That commit is more than a > > year > > and a half old, so I wonder. > > > Yes, we encountered many kernel exceptions of > VM_BUG_ON(zspage->isolated == 0) in dec_zspage_isolation() and > BUG_ON(!pages[1]) in zs_unmap_object() lately. > This issue only occurs when migration and reclamation occur at the > same time. With our memory stress test, we can reproduce this issue > several times a day. We have no idea why no one else encountered > this issue. BTW, we switched to the new kernel version with this > defect a few months ago. Ah. It's important that such information be in the changelog! I have put this info into my copy of the v1 patch's changelog. I have moved the v1 patch from the mm-unstable branch into mm-hotfixes-unstable, so it is staged for merging in this -rc cycle. I have also added a cc:stable so that the fix gets backported into kernels which contain c4549b871102. I have added a note-to-self that a v2 patch is expected.
