> On Mon, Nov 07, 2022 at 10:47:33PM +0100, Petr Vorel wrote: > > Hi Minchan, > > > On Mon, Nov 07, 2022 at 08:11:35PM +0100, Petr Vorel wrote: > > > > Hi all, > > > > following bug is trying to workaround an error on ppc64le, where > > > > zram01.sh LTP test (there is also kernel selftest > > > > tools/testing/selftests/zram/zram01.sh, but LTP test got further > > > > updates) has often mem_used_total 0 although zram is already filled. > > > Hi, Petr, > > > Is it happening on only ppc64le? > > I haven't seen it on other archs (x86_64, aarch64). > > > Is it a new regression? What kernel version did you use? > > Found on openSUSE kernel, which uses stable kernel releases 6.0.x. > > It's probably much older, first I've seen it some years ago (I'm not able to find kernel version), but it was random. Now it's much more common. > > Test runs on VM (I can give qemu command or whatever you need to know about it) > > I'll try to verify it on some bare metal ppc64le. > Hi Petr and Martin, > Thanks for testing and meaning information. > Could you tell how I could create VM to run ppc64le and run the test? > I'd like to reproduce in my local to debug it. I suppose you don't have ppc64le bare metal machine, thus you run on x86_64. One way would be to install on host qemu-system-ppc64, download iso image of any distro which supports ppc64le and install it with virt-manager (which would fill necessary qemu params). Other way, which I often use is to compile system with Buildroot distribution. You can clone my Buildroot distro fork, branch debug/zram [1]. I put there in 3 commits my configuration. I added 0001-zram-Debug-mm_stat_show.patch [2] on the top of 6.0.7 with little debugging. What is now only needed is to 1) install on host qemu-system-ppc64 (speedup build + Buildroot is configured not to compile qemu-system-ppc64), then: $ make # takes time $ ./output/images/start-qemu.sh serial-only When I have ppc64le host with enough space, I often use rapido [3], but that crashed stable kernel (another story which I'll report soon). Hope that helps. Kind regards, Petr [1] https://github.com/pevik/buildroot/commits/debug/zram [2] https://github.com/pevik/buildroot/blob/debug/zram/0001-zram-Debug-mm_stat_show.patch [3] https://github.com/rapido-linux/rapido
