I can reproduce with qemu: # ls /sys/block/nvme*n1/mq/*/cpu_list /sys/block/nvme0n1/mq/0/cpu_list /sys/block/nvme0n1/mq/1/cpu_list /sys/block/nvme0n1/mq/2/cpu_list /sys/block/nvme0n1/mq/3/cpu_list /sys/block/nvme0n1/mq/4/cpu_list /sys/block/nvme0n1/mq/5/cpu_list /sys/block/nvme0n1/mq/6/cpu_list Here is the qemu cmdline emulating 8-queue nvme while the VM has 12 cpu: # qemu-system-x86_64 -m 4096 -smp 12 \ -kernel /path-to-kernel/linux-4.18.10/arch/x86_64/boot/bzImage \ -hda /path-to-img/ubuntu1804.qcow2 \ -append "root=/dev/sda1 init=/sbin/init text" -enable-kvm \ -net nic -net user,hostfwd=tcp::5022-:22 \ -device nvme,drive=nvme1,serial=deadbeaf1,num_queues=8 \ -drive file=/path-to-img/nvme.disk,if=none,id=nvme1 Dongli Zhang On 10/08/2018 01:05 PM, Prasun Ratn wrote: > Hi > > I have an NVMe SSD that has 8 hw queues and on older kernels I see all > 8 show up. However on a recent kernel (I tried 4.18), I only see 7. Is > this a known issue? > > $ uname -r > 4.14.1-1.el7.elrepo.x86_64 > > $ ls /sys/block/nvme*n1/mq/*/cpu_list > /sys/block/nvme0n1/mq/0/cpu_list > /sys/block/nvme0n1/mq/1/cpu_list > /sys/block/nvme0n1/mq/2/cpu_list > /sys/block/nvme0n1/mq/3/cpu_list > /sys/block/nvme0n1/mq/4/cpu_list > /sys/block/nvme0n1/mq/5/cpu_list > /sys/block/nvme0n1/mq/6/cpu_list > /sys/block/nvme0n1/mq/7/cpu_list > /sys/block/nvme1n1/mq/0/cpu_list > /sys/block/nvme1n1/mq/1/cpu_list > /sys/block/nvme1n1/mq/2/cpu_list > /sys/block/nvme1n1/mq/3/cpu_list > /sys/block/nvme1n1/mq/4/cpu_list > /sys/block/nvme1n1/mq/5/cpu_list > /sys/block/nvme1n1/mq/6/cpu_list > /sys/block/nvme1n1/mq/7/cpu_list > /sys/block/nvme2n1/mq/0/cpu_list > /sys/block/nvme2n1/mq/1/cpu_list > /sys/block/nvme2n1/mq/2/cpu_list > /sys/block/nvme2n1/mq/3/cpu_list > /sys/block/nvme2n1/mq/4/cpu_list > /sys/block/nvme2n1/mq/5/cpu_list > /sys/block/nvme2n1/mq/6/cpu_list > /sys/block/nvme2n1/mq/7/cpu_list > /sys/block/nvme3n1/mq/0/cpu_list > /sys/block/nvme3n1/mq/1/cpu_list > /sys/block/nvme3n1/mq/2/cpu_list > /sys/block/nvme3n1/mq/3/cpu_list > /sys/block/nvme3n1/mq/4/cpu_list > /sys/block/nvme3n1/mq/5/cpu_list > /sys/block/nvme3n1/mq/6/cpu_list > /sys/block/nvme3n1/mq/7/cpu_list > > > $ uname -r > 4.18.10-1.el7.elrepo.x86_64 > > $ ls /sys/block/nvme*n1/mq/*/cpu_list > /sys/block/nvme0n1/mq/0/cpu_list > /sys/block/nvme0n1/mq/1/cpu_list > /sys/block/nvme0n1/mq/2/cpu_list > /sys/block/nvme0n1/mq/3/cpu_list > /sys/block/nvme0n1/mq/4/cpu_list > /sys/block/nvme0n1/mq/5/cpu_list > /sys/block/nvme0n1/mq/6/cpu_list > /sys/block/nvme1n1/mq/0/cpu_list > /sys/block/nvme1n1/mq/1/cpu_list > /sys/block/nvme1n1/mq/2/cpu_list > /sys/block/nvme1n1/mq/3/cpu_list > /sys/block/nvme1n1/mq/4/cpu_list > /sys/block/nvme1n1/mq/5/cpu_list > /sys/block/nvme1n1/mq/6/cpu_list > /sys/block/nvme2n1/mq/0/cpu_list > /sys/block/nvme2n1/mq/1/cpu_list > /sys/block/nvme2n1/mq/2/cpu_list > /sys/block/nvme2n1/mq/3/cpu_list > /sys/block/nvme2n1/mq/4/cpu_list > /sys/block/nvme2n1/mq/5/cpu_list > /sys/block/nvme2n1/mq/6/cpu_list > /sys/block/nvme3n1/mq/0/cpu_list > /sys/block/nvme3n1/mq/1/cpu_list > /sys/block/nvme3n1/mq/2/cpu_list > /sys/block/nvme3n1/mq/3/cpu_list > /sys/block/nvme3n1/mq/4/cpu_list > /sys/block/nvme3n1/mq/5/cpu_list > /sys/block/nvme3n1/mq/6/cpu_list >
