Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> writes: > On Wed, Nov 18, 2015 at 08:52:59AM -0800, Dan Williams wrote: >> Sysrq-t or sysrq-w dump? Also do you have the locking fix from Yigal? >> >> https://lists.01.org/pipermail/linux-nvdimm/2015-November/002842.html > > I was able to reproduce the issue in my setup with v4.3, and the patch from > Yigal seems to solve it. Jeff, can you confirm? I applied the patch from Yigal and the symptoms persist. Ross, what are you testing on? I'm using an NVDIMM-N. Dan, here's sysrq-l (which is what w used to look like, I think). Only cpu 3 is interesting: [ 825.339264] NMI backtrace for cpu 3 [ 825.356347] CPU: 3 PID: 13555 Comm: blk_non_zero.st Not tainted 4.4.0-rc1+ #17 [ 825.392056] Hardware name: HP ProLiant DL380 Gen9, BIOS P89 06/09/2015 [ 825.424472] task: ffff880465bf6a40 ti: ffff88046133c000 task.ti: ffff88046133c000 [ 825.461480] RIP: 0010:[<ffffffff81329856>] [<ffffffff81329856>] strcmp+0x6/0x30 [ 825.497916] RSP: 0000:ffff88046133fbc8 EFLAGS: 00000246 [ 825.524836] RAX: 0000000000000000 RBX: ffff880c7fffd7c0 RCX: 000000076c800000 [ 825.566847] RDX: 000000076c800fff RSI: ffffffff818ea1c8 RDI: ffffffff818ea1c8 [ 825.605265] RBP: ffff88046133fbc8 R08: 0000000000000001 R09: ffff8804652300c0 [ 825.643628] R10: 00007f1b4fe0b000 R11: ffff880465230228 R12: ffffffff818ea1bd [ 825.681381] R13: 0000000000000001 R14: ffff88046133fc20 R15: 0000000080000200 [ 825.718607] FS: 00007f1b5102d880(0000) GS:ffff88046f8c0000(0000) knlGS:00000000000000 00 [ 825.761663] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 825.792213] CR2: 00007f1b4fe0b000 CR3: 000000046b225000 CR4: 00000000001406e0 [ 825.830906] Stack: [ 825.841235] ffff88046133fc10 ffffffff81084610 000000076c800000 000000076c800fff [ 825.879533] 000000076c800fff 00000000ffffffff ffff88046133fc90 ffffffff8106d1d0 [ 825.916774] 000000000000000c ffff88046133fc80 ffffffff81084f0d 000000076c800000 [ 825.953220] Call Trace: [ 825.965386] [<ffffffff81084610>] find_next_iomem_res+0xd0/0x130 [ 825.996804] [<ffffffff8106d1d0>] ? pat_enabled+0x20/0x20 [ 826.024773] [<ffffffff81084f0d>] walk_system_ram_range+0x8d/0xf0 [ 826.055565] [<ffffffff8106d2d8>] pat_pagerange_is_ram+0x78/0xa0 [ 826.088971] [<ffffffff8106d475>] lookup_memtype+0x35/0xc0 [ 826.121385] [<ffffffff8106e33b>] track_pfn_insert+0x2b/0x60 [ 826.154600] [<ffffffff811e5523>] vmf_insert_pfn_pmd+0xb3/0x210 [ 826.187992] [<ffffffff8124acab>] __dax_pmd_fault+0x3cb/0x610 [ 826.221337] [<ffffffffa0769910>] ? ext4_dax_mkwrite+0x20/0x20 [ext4] [ 826.259190] [<ffffffffa0769a4d>] ext4_dax_pmd_fault+0xcd/0x100 [ext4] [ 826.293414] [<ffffffff811b0af7>] handle_mm_fault+0x3b7/0x510 [ 826.323763] [<ffffffff81068f98>] __do_page_fault+0x188/0x3f0 [ 826.358186] [<ffffffff81069230>] do_page_fault+0x30/0x80 [ 826.391212] [<ffffffff8169c148>] page_fault+0x28/0x30 [ 826.420752] Code: 89 e5 74 09 48 83 c2 01 80 3a 00 75 f7 48 83 c6 01 0f b6 4e ff 48 83 c2 01 84 c9 88 4a ff 75 ed 5d c3 0f 1f 00 55 48 89 e5 eb 04 <84> c0 74 18 48 83 c7 01 0f b6 47 ff 48 83 c6 01 3a 46 ff 74 eb The full output is large (48 cpus), so I'm going to be lazy and not cut-n-paste it here. Cheers, Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html