Hi, I haven't read through the implementation yet but I have say that I really love this cover letter. It is clear on intetion, it covers design from high level enough to start discussion and provides a very nice testing coverage. Nice work! I also think that we need a better performing vmalloc implementation long term because of the increasing number of kvmalloc users. I just have two mostly workflow specific comments. > A test-suite patch you can find here, it is based on 4.18 kernel. > ftp://vps418301.ovh.net/incoming/0001-mm-vmalloc-stress-test-suite-v4.18.patch Can you fit this stress test into the standard self test machinery? > It is fixed by second commit in this series. Please see more description in > the commit message of the patch. Bug fixes should go first and new functionality should be built on top. A kernel crash sounds serious enough to have a fix marked for stable. If the fix is too hard/complex then we might consider a revert of the faulty commit. > > 3) This one is related to PCPU allocator(see pcpu_alloc_test()). In that > stress test case i see that SUnreclaim(/proc/meminfo) parameter gets increased, > i.e. there is a memory leek somewhere in percpu allocator. It sounds like > a memory that is allocated by pcpu_get_vm_areas() sometimes is not freed. > Resulting in memory leaking or "Kernel panic": > > ---[ end Kernel panic - not syncing: Out of memory and no killable processes... It would be great to pin point this one down before the rework as well. Thanks a lot! -- Michal Hocko SUSE Labs
