Hi, After upgrading my sparc to 6.9.5 I noticed that attempting to run xfsdump instantly (within a couple seconds) and reliably crashes the kernel. The same problem is also observed on 6.10-rc4. This is a regression introduced around 6.4 timeframe. 6.3 appears to work fine and xfsdump goes about its business dumping stuff. Bisection implicates the following: 062eacf57ad91b5c272f89dc964fd6dd9715ea7d is the first bad commit commit 062eacf57ad91b5c272f89dc964fd6dd9715ea7d Author: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx> Date: Thu Mar 30 21:06:38 2023 +0200 mm: vmalloc: remove a global vmap_blocks xarray This reverts pretty easily on top of v6.10-rc4, as long as I first revert fa1c77c13ca5 ("mm: vmalloc: rename addr_to_vb_xarray() function") as this just causes conflicts. Then there is one easily-corrected build failure (adjust the one remaining &vbq->vmap_blocks back to &vmap_blocks). If I do all of that then the kernel is not crashing anymore. A splat like this one is output on the console when the crash occurs (varies a bit): spitfire_data_access_exception: SFSR[000000000080100d] SFAR[0000000000c51ba0], going. \|/ ____ \|/ "@'/ .. \`@" /_| \__/ |_\ \__U_/ xfsdump(2028): Dax [#1] CPU: 0 PID: 2028 Comm: xfsdump Not tainted 6.9.5 #199 TSTATE: 0000000811001607 TPC: 0000000000974fc4 TNPC: 0000000000974fc8 Y: 00000000 Not tainted TPC: <queued_spin_lock_slowpath+0x1d0/0x2cc> g0: 0000000000aa9110 g1: 0000000000c51ba0 g2: 444b000000000000 g3: 0000000000c560c0 g4: fffff800a71a1f00 g5: fffff800bebb6000 g6: fffff800ac0ec000 g7: 0000000000040000 o0: 0000000000000002 o1: 00000000000007d8 o2: fffff800a4131420 o3: ffffffff0000ffff o4: 00000000900a2001 o5: 0000000000c4f5a0 sp: fffff800ac0eeac1 ret_pc: 0000000000040000 RPC: <0x40000> l0: fffff800a40098c0 l1: 0000000100800000 l2: 0000000000000000 l3: 0000000000000103 l4: fffff800a40081b0 l5: 0000000000aeec00 l6: fffff800a40080a0 l7: 0000000101000000 i0: 0000000000c4f5a0 i1: 00000000900a2001 i2: 0000000000000000 i3: fffff800bf807b80 i4: 0000000000000000 i5: fffff800bf807b80 i6: fffff800ac0eeb71 i7: 0000000000503438 I7: <vm_map_ram+0x210/0x724> Call Trace: [<0000000000503438>] vm_map_ram+0x210/0x724 [<00000000006661f8>] _xfs_buf_map_pages+0x58/0xa0 [<0000000000667058>] xfs_buf_get_map+0x668/0x7a4 [<00000000006673e0>] xfs_buf_read_map+0x20/0x160 [<0000000000667548>] xfs_buf_readahead_map+0x28/0x38 [<000000000067a4f8>] xfs_iwalk_ichunk_ra.isra.0+0xa8/0xc4 [<000000000067a8f0>] xfs_iwalk_ag+0x1c0/0x260 [<000000000067ab08>] xfs_iwalk+0xdc/0x130 [<0000000000679fc8>] xfs_bulkstat+0x10c/0x140 [<0000000000695528>] xfs_compat_ioc_fsbulkstat+0x1a4/0x1e8 [<000000000069572c>] xfs_file_compat_ioctl+0x8c/0x1f4 [<0000000000534ab0>] compat_sys_ioctl+0x9c/0xfc [<0000000000406214>] linux_sparc_syscall32+0x34/0x60 Disabling lock debugging due to kernel taint Caller[0000000000503438]: vm_map_ram+0x210/0x724 Caller[00000000006661f8]: _xfs_buf_map_pages+0x58/0xa0 Caller[0000000000667058]: xfs_buf_get_map+0x668/0x7a4 Caller[00000000006673e0]: xfs_buf_read_map+0x20/0x160 Caller[0000000000667548]: xfs_buf_readahead_map+0x28/0x38 Caller[000000000067a4f8]: xfs_iwalk_ichunk_ra.isra.0+0xa8/0xc4 Caller[000000000067a8f0]: xfs_iwalk_ag+0x1c0/0x260 Caller[000000000067ab08]: xfs_iwalk+0xdc/0x130 Caller[0000000000679fc8]: xfs_bulkstat+0x10c/0x140 Caller[0000000000695528]: xfs_compat_ioc_fsbulkstat+0x1a4/0x1e8 Caller[000000000069572c]: xfs_file_compat_ioctl+0x8c/0x1f4 Caller[0000000000534ab0]: compat_sys_ioctl+0x9c/0xfc Caller[0000000000406214]: linux_sparc_syscall32+0x34/0x60 Caller[00000000f789ccdc]: 0xf789ccdc Instruction DUMP: 8610e0c0 8400c002 c458a0f8 <f6704002> c206e008 80a06000 12400012 01000000 81408000 Let me know if you need any more info! Thanks, Nick