On Sat, Jun 16, 2018 at 06:59:38PM -0700, Matthew Wilcox wrote: > The XArray is a replacement for the radix tree. For the moment it uses > the same data structures, enabling a gradual replacement. This patch > set implements the XArray and converts the page cache to use it. > > A version of these patches has been running under xfstests for over > 48 hours, so I have some confidence in them. The DAX changes have now > also had a reasonable test outing. This is based on next-20180615 and > is available as a git tree at > git://git.infradead.org/users/willy/linux-dax.git xarray-20180615 > > I shall create a git branch from -rc1 and ask for that to be included in > -next. I'm a little concerned I still have no reviews on some of the > later patches. > > Changes since v13: > - Actually fixed bug in workingset conversion that led to exceptional > entries not being deleted from the XArray. Not sure how I dropped > that patch for v13. Thanks to David Sterba for noticing. > - Fixed bug in DAX writeback conversion that failed to wake up waiters. > Thanks to Ross for testing, and to Dan & Jeff for helping me get a > setup working to reproduce the problem. > - Converted the new dax_lock_page / dax_unlock_page functions. > - Moved XArray test suite entirely into the test_xarray kernel module > to match other test suites. It can still be built in userspace as > part of the radix tree test suite. > - Changed email address. > - Moved a few functions into different patches to make the test-suite > additions more logical. > - Fixed a bug in XA_BUG_ON (oh the irony) where it evaluated the > condition twice. > - Constified xa_head() / xa_parent() / xa_entry() and their _locked > variants. > - Moved xa_parent() to xarray.h so it can be used from the workingset code. > - Call the xarray testsuite from the radix tree test suite to ensure > that I remember to run both test suites ;-) > - Added some more tests to the test suite. Hit another deadlock. This one reproduces 100% of the time in my setup with XFS + DAX + generic/340. It doesn't reproduce for me at all with next-20180615. Here's the output from "echo w > /proc/sysrq-trigger": [ 92.849119] sysrq: SysRq : Show Blocked State [ 92.850506] task PC stack pid father [ 92.852299] holetest D 0 1651 1466 0x00000000 [ 92.853912] Call Trace: [ 92.854610] __schedule+0x2c5/0xad0 [ 92.855612] schedule+0x36/0x90 [ 92.856602] get_unlocked_entry+0xce/0x120 [ 92.857756] ? dax_insert_entry+0x2b0/0x2b0 [ 92.858931] grab_mapping_entry+0x19e/0x250 [ 92.860119] dax_iomap_pte_fault+0x115/0x1140 [ 92.860836] dax_iomap_fault+0x37/0x40 [ 92.861235] __xfs_filemap_fault+0x2de/0x310 [ 92.861681] xfs_filemap_fault+0x2c/0x30 [ 92.862113] __do_fault+0x26/0x160 [ 92.862531] __handle_mm_fault+0xc96/0x1320 [ 92.863059] handle_mm_fault+0x1ba/0x3c0 [ 92.863534] __do_page_fault+0x2b4/0x590 [ 92.864029] do_page_fault+0x38/0x2c0 [ 92.864472] do_async_page_fault+0x2c/0xb0 [ 92.864985] ? async_page_fault+0x8/0x30 [ 92.865459] async_page_fault+0x1e/0x30 [ 92.865941] RIP: 0033:0x401442 [ 92.866322] Code: Bad RIP value. [ 92.866739] RSP: 002b:00007fa29c9feec0 EFLAGS: 00010212 [ 92.867366] RAX: 00007fa29ca00400 RBX: 0000000000001000 RCX: 0000000000008000 [ 92.868219] RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000000 [ 92.869082] RBP: 00007fa29c9ff700 R08: 00007fa29c9ff700 R09: 00007fa29c9ff700 [ 92.869939] R10: 0000000000000070 R11: 00007fa29e571ba0 R12: 00007fa29ca00000 [ 92.870804] R13: 00007fffd5f24160 R14: 0000000000000400 R15: 00007fffd5f240b0 This looks very similar to the one I reported last week with generic/269. - Ross
