FYI, we noticed the following commit:

commit: 88de48a57949c9329c99de454936fd3e8bbf0e65 ("brd: remove discard support")
git://git.infradead.org/users/hch/block.git discard-rework

in testcase: pft
with following parameters:


test-description: Pft is the page fault test micro benchmark.
test-url: https://github.com/gormanm/pft


on test machine: qemu-system-x86_64 -enable-kvm -cpu Penryn -smp 4 -m 2G

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


[   15.149623] Dev ram0: unable to read RDB block 1
[   15.150913] Buffer I/O error on dev ram0, logical block 0, async page read
[   15.152676] Buffer I/O error on dev ram0, logical block 0, async page read
[   15.154596]  ram0: unable to read partition table
[   15.156674] ldm_validate_partition_table(): Disk read failed.
[   15.157976] Dev ram1: unable to read RDB block 0
[   15.159202]  ram1: unable to read partition table
[   15.161227] ldm_validate_partition_table(): Disk read failed.
[   15.163144] FDC 0 is a S82078B
[   15.166449] Dev ram2: unable to read RDB block 0
[   15.167751]  ram2: unable to read partition table
[   15.169806] ldm_validate_partition_table(): Disk read failed.
[   15.171468] Dev ram3: unable to read RDB block 0
[   15.172816]  ram3: unable to read partition table
[   15.175026] ldm_validate_partition_table(): Disk read failed.
[   15.176619] Dev ram4: unable to read RDB block 0
[   15.177990]  ram4: unable to read partition table
[   15.180079] ldm_validate_partition_table(): Disk read failed.
[   15.181671] Dev ram5: unable to read RDB block 0
[   15.183083]  ram5: unable to read partition table
[   15.185175] ldm_validate_partition_table(): Disk read failed.
[   15.186821] Dev ram6: unable to read RDB block 0
[   15.188202]  ram6: unable to read partition table
[   15.190408] ldm_validate_partition_table(): Disk read failed.
[   15.192003] Dev ram7: unable to read RDB block 0
[   15.193339]  ram7: unable to read partition table
[   15.195456] ldm_validate_partition_table(): Disk read failed.
[   15.197032] Dev ram8: unable to read RDB block 0
[   15.198435]  ram8: unable to read partition table
[   15.200500] ldm_validate_partition_table(): Disk read failed.
[   15.202075] Dev ram9: unable to read RDB block 0
[   15.203485]  ram9: unable to read partition table
[   15.205525] ldm_validate_partition_table(): Disk read failed.
[   15.207185] Dev ram10: unable to read RDB block 0
[   15.208508]  ram10: unable to read partition table
[   15.210653] ldm_validate_partition_table(): Disk read failed.
[   15.212270] Dev ram11: unable to read RDB block 0
[   15.213620]  ram11: unable to read partition table
[   15.215747] ldm_validate_partition_table(): Disk read failed.
[   15.217333] Dev ram12: unable to read RDB block 0
[   15.218781]  ram12: unable to read partition table
[   15.220910] ldm_validate_partition_table(): Disk read failed.
[   15.222631] Dev ram13: unable to read RDB block 0
[   15.224010]  ram13: unable to read partition table
[   15.226111] ldm_validate_partition_table(): Disk read failed.
[   15.227747] Dev ram14: unable to read RDB block 0
[   15.229201]  ram14: unable to read partition table




To reproduce:

        git clone https://github.com/01org/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
Xiaolong