On 05.10.2023 17:08, Biju Das wrote: > Hi Peter Zijlstra, > >> Subject: Re: [PATCH] sched/fair: fix pick_eevdf to always find the correct >> se >> >> On Thu, Oct 05, 2023 at 07:31:34AM +0000, Biju Das wrote: >> >>> [ 26.099203] EEVDF scheduling fail, picking leftmost >> This, that the problem.. the rest is just noise because printk stinks. >> >> Weirdly have not seen that trigger, and I've been running with this patch >> on for a few days now :/ > I agree Original issue is "EEVDF scheduling fail, picking leftmost" > Which is triggering noisy lock warning messages during boot. > > 2 platforms are affected both ARM platforms(Renesas and Samsung) > Maybe other platforms affected too. Just to note, I've run into this issue on the QEmu's 'arm64/virt' platform, not on the Samsung specific hardware. You can easily reproduce it with the following steps: # make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig # ./scripts/config -e PROVE_LOCKING -e DEBUG_ATOMIC_SLEEP -e PM_DEBUG -e PM_ADVANCED_DEBUG # make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- olddefconfig Image.gz # wget https://cloud.debian.org/images/cloud/buster/20230802-1460/debian-10-nocloud-arm64-20230802-1460.tar.xz # tar xJfv debian-10-nocloud-arm64-20230802-1460.tar.xz Then run QEmu a few times until you see the lockdep splat: # qemu-system-aarch64 -serial stdio -kernel arch/arm64/boot/Image -append "console=ttyAMA0 root=/dev/vda1 rootwait" -M virt -cpu cortex-a57 -smp 2 -m 1024 -netdev user,id=user -device virtio-net-device,netdev=user -display none -device virtio-blk-device,drive=virtio-blk0 -drive file=disk.raw,id=virtio-blk0,if=none,format=raw I have no idea if this is ARM64-specific anyhow, but this is how I reproduced it. I hope this guide helps fixing the bug! Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
