From: Ross Zwisler Subject: Re: [RFC v3] [PATCH 0/18] DAX page fault locking Date: Tue, 10 May 2016 16:39:37 -0600 Message-ID: <20160510223937.GA10222@linux.intel.com> References: <1461015341-20153-1-git-send-email-jack@suse.cz> <20160506203308.GA12506@linux.intel.com> <20160509093828.GF11897@quack2.suse.cz> <20160510152814.GQ11897@quack2.suse.cz> <20160510203003.GA5314@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Ross Zwisler , Jan Kara , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Dan Williams , linux-nvdimm@lists.01.org, Matthew Wilcox Return-path: Content-Disposition: inline In-Reply-To: <20160510203003.GA5314@linux.intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On Tue, May 10, 2016 at 02:30:03PM -0600, Ross Zwisler wrote: > On Tue, May 10, 2016 at 05:28:14PM +0200, Jan Kara wrote: > > On Mon 09-05-16 11:38:28, Jan Kara wrote: > > Somehow, I'm not able to reproduce the warnings... Anyway, I think I see > > what's going on. Can you check whether the warning goes away when you > > change the condition at the end of page_cache_tree_delete() to: > > > > if (!dax_mapping(mapping) && !workingset_node_pages(node) && > > list_empty(&node->private_list)) { > > Yep, this took care of both of the issues that I reported. I'll restart my > testing with this in my baseline, but as of this fix I don't have any more > open testing issues. :) Well, looks like I spoke too soon. The two tests that were failing for me are now passing, but I can still create what looks like a related failure using XFS, DAX, and the two xfstests generic/231 and generic/232 run back-to-back. Here's the shell: # ./check generic/231 generic/232 FSTYP -- xfs (debug) PLATFORM -- Linux/x86_64 alara 4.6.0-rc5jan_testing_2+ MKFS_OPTIONS -- -f -bsize=4096 /dev/pmem0p2 MOUNT_OPTIONS -- -o dax -o context=system_u:object_r:nfs_t:s0 /dev/pmem0p2 /mnt/xfstests_scratch generic/231 88s ... 88s generic/232 2s ..../check: line 543: 9105 Segmentation fault ./$seq > $tmp.rawout 2>&1 [failed, exit status 139] - output mismatch (see /root/xfstests/results//generic/232.out.bad) --- tests/generic/232.out 2015-10-02 10:19:36.806795894 -0600 +++ /root/xfstests/results//generic/232.out.bad 2016-05-10 16:17:54.805637876 -0600 @@ -3,5 +3,3 @@ Testing fsstress seed = S -Comparing user usage -Comparing group usage ... (Run 'diff -u tests/generic/232.out /root/xfstests/results//generic/232.out.bad' to see the entire diff) and the serial log: run fstests generic/232 at 2016-05-10 16:17:53 XFS (pmem0p2): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (pmem0p2): Mounting V5 Filesystem XFS (pmem0p2): Ending clean mount XFS (pmem0p2): Quotacheck needed: Please wait. XFS (pmem0p2): Quotacheck: Done. ------------[ cut here ]------------ kernel BUG at mm/workingset.c:423! invalid opcode: 0000 [#1] SMP Modules linked in: nd_pmem nd_btt nd_e820 libnvdimm CPU: 1 PID: 9105 Comm: 232 Not tainted 4.6.0-rc5jan_testing_2+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 task: ffff8801f4eb98c0 ti: ffff88040e5f0000 task.ti: ffff88040e5f0000 RIP: 0010:[] [] shadow_lru_isolate+0x183/0x1a0 RSP: 0018:ffff88040e5f3be8 EFLAGS: 00010006 RAX: ffff880401f68270 RBX: ffff880401f68260 RCX: ffff880401f68470 RDX: 000000000000006c RSI: 0000000000000000 RDI: ffff880410b2bd80 RBP: ffff88040e5f3c10 R08: 0000000000000008 R09: 0000000000000000 R10: ffff8800b59eb840 R11: 0000000000000080 R12: ffff880410b2bd80 R13: ffff8800b59eb828 R14: ffff8800b59eb810 R15: ffff880410b2bdc8 FS: 00007fb73c58c700(0000) GS:ffff88041a200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb73c5a4000 CR3: 000000040e139000 CR4: 00000000000006e0 Stack: ffff880410b2bd80 ffff880410b2bdc8 ffff88040e5f3d18 ffff880410b2bdc8 ffff880401f68260 ffff88040e5f3c60 ffffffff81206c7f 0000000000000000 0000000000000000 ffffffff81207a10 ffff88040e5f3d10 0000000000000000 Call Trace: [] __list_lru_walk_one.isra.3+0x9f/0x150 mm/list_lru.c:223 [] list_lru_walk_one+0x23/0x30 mm/list_lru.c:263 [< inline >] list_lru_shrink_walk include/linux/list_lru.h:170 [] scan_shadow_nodes+0x3a/0x50 mm/workingset.c:457 [< inline >] do_shrink_slab mm/vmscan.c:344 [] shrink_slab.part.40+0x1fe/0x420 mm/vmscan.c:442 [] shrink_slab+0x29/0x30 mm/vmscan.c:406 [] drop_slab_node+0x31/0x60 mm/vmscan.c:460 [] drop_slab+0x3f/0x70 mm/vmscan.c:471 [] drop_caches_sysctl_handler+0x69/0xb0 fs/drop_caches.c:58 [] proc_sys_call_handler+0xe7/0x100 fs/proc/proc_sysctl.c:543 [] proc_sys_write+0x14/0x20 fs/proc/proc_sysctl.c:561 [] __vfs_write+0x37/0x120 fs/read_write.c:529 [] vfs_write+0xac/0x1a0 fs/read_write.c:578 [< inline >] SYSC_write fs/read_write.c:625 [] SyS_write+0x58/0xd0 fs/read_write.c:617 [] entry_SYSCALL_64_fastpath+0x1f/0xbd arch/x86/entry/entry_64.S:207 Code: 66 90 66 66 90 e8 4e 53 88 00 fa 66 66 90 66 66 90 e8 52 5c ef ff 4c 89 e7 e8 ba a1 88 00 89 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 66 66 66 66 66 66 2e RIP [] shadow_lru_isolate+0x183/0x1a0 mm/workingset.c:448 RSP ---[ end trace c4ff9bc94605ec45 ]--- This was against a tree with your most recent fix. The full tree can be found here: https://git.kernel.org/cgit/linux/kernel/git/zwisler/linux.git/log/?h=jan_testing This only recreates on about 1/2 of the runs of these tests in my system. Thanks, - Ross -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org