On 2025/7/7 9:43, Joseph Qi wrote: > > > On 2025/7/5 15:10, Zhang Yi wrote: >> On 2025/7/3 18:47, Joseph Qi wrote: >>> >>> >>> On 2025/7/3 15:26, Naresh Kamboju wrote: >>>> On Thu, 26 Jun 2025 at 19:23, Zhang Yi <yi.zhang@xxxxxxxxxxxxxxx> wrote: >>>>> >>>>> Hi, Naresh! >>>>> >>>>> On 2025/6/26 20:31, Naresh Kamboju wrote: >>>>>> Regressions noticed on arm64 devices while running LTP syscalls mmap16 >>>>>> test case on the Linux next-20250616..next-20250626 with the extra build >>>>>> config fragment CONFIG_ARM64_64K_PAGES=y the kernel warning noticed. >>>>>> >>>>>> Not reproducible with 4K page size. >>>>>> >>>>>> Test environments: >>>>>> - Dragonboard-410c >>>>>> - Juno-r2 >>>>>> - rk3399-rock-pi-4b >>>>>> - qemu-arm64 >>>>>> >>>>>> Regression Analysis: >>>>>> - New regression? Yes >>>>>> - Reproducibility? Yes >>>>>> >>>>>> Test regression: next-20250626 LTP mmap16 WARNING fs jbd2 >>>>>> transaction.c start_this_handle >>>>>> >>>>>> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx> >>>>> >>>>> Thank you for the report. The block size for this test is 1 KB, so I >>>>> suspect this is the issue with insufficient journal credits that we >>>>> are going to resolve. >>>> >>>> I have applied your patch set [1] and tested and the reported >>>> regressions did not fix. >>>> Am I missing anything ? >>>> >>>> [1] https://lore.kernel.org/linux-ext4/20250611111625.1668035-1-yi.zhang@xxxxxxxxxxxxxxx/ >>>> >>> >>> I can also reproduce the similar warning with xfstests generic/730 under >>> 64k page size + 4k block size. >>> >> >> Hi, Joseph! >> >> I cannot reproduce this issue on my machine. Theoretically, the 'rsv_credits' >> should be 113 under 64k page size + 4k block size, I don't think it would >> exceed the max user trans buffers. Could you please give more details? >> What is the configuration of your xfstests? and what does the specific error >> log look like? >> > I'm testing on arm 64K ECS with xfstests local.config as follows: > > export TEST_DEV=/dev/nvme1n1p1 > export TEST_DIR=/mnt/test > export SCRATCH_DEV=/dev/nvme1n1p2 > export SCRATCH_MNT=/mnt/scratch > > Each disk part is 250G and formated with 4k block size. > > The dmesg shows the following warning: > > [ 137.174661] JBD2: kworker/u32:0 wants too many credits credits:32 rsv_credits:1577 max:2695 > ... > [ 137.175544] Call trace: > [ 137.175545] start_this_handle+0x3bc/0x3d8 (P) > [ 137.175548] jbd2__journal_start+0x10c/0x248 > [ 137.175550] __ext4_journal_start_sb+0xe4/0x1b0 > [ 137.175553] ext4_do_writepages+0x430/0x768 > [ 137.175556] ext4_writepages+0x8c/0x118 > [ 137.175558] do_writepages+0xac/0x180 > [ 137.175561] __writeback_single_inode+0x48/0x328 > [ 137.175563] writeback_sb_inodes+0x244/0x4a0 > [ 137.175564] wb_writeback+0xec/0x3a0 > [ 137.175566] wb_do_writeback+0xc0/0x250 > [ 137.175568] wb_workfn+0x70/0x1b0 > [ 137.175570] process_one_work+0x180/0x400 > [ 137.175573] worker_thread+0x254/0x2c8 > [ 137.175575] kthread+0x124/0x130 > [ 137.175577] ret_from_fork+0x10/0x20 > ... OK, well. Since you did not specifically set MKFS_OPTIONS="-b 4096, the generic/730 will use scsi_debug to create a file system image with a size of 256MB, a block size of 1KB, and a log size of 8MB. Consequently, the issue did not actually occur in a 4KB block size environment, so the root cause is the same as Naresh's report. Thanks, Yi.
