dbuf_create() VERIFY(dn->dn_type != DMU_OT_NONE) failed #5396
Milestone
Comments
13 tasks
behlendorf
added a commit
to behlendorf/zfs
that referenced
this issue
Aug 25, 2017
As part of commit 50c957f this check was pulled up before the call to dnode_create(). This is racy since the dnode_phys_t in the dbuf could be updated after the check passed but before it's created by dnode_create(). Close the race by adding the original check back to detect this unlikely case. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes openzfs#5396 Closes openzfs#6522
13 tasks
behlendorf
added a commit
to behlendorf/zfs
that referenced
this issue
Aug 25, 2017
As part of commit 50c957f this check was pulled up before the call to dnode_create(). This is racy since the dnode_phys_t in the dbuf could be updated after the check passed but before it's created by dnode_create(). Close the race by adding the original check back to detect this unlikely case. TEST_ZFSSTRESS_RUNTIME=7200 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes openzfs#5396 Closes openzfs#6522
behlendorf
added a commit
to behlendorf/zfs
that referenced
this issue
Aug 25, 2017
As part of commit 50c957f this check was pulled up before the call to dnode_create(). This is racy since the dnode_phys_t in the dbuf could be updated after the check passed but before it's created by dnode_create(). Close the race by adding the original check back to detect this unlikely case. TEST_XFSTESTS_SKIP="yes" TEST_ZFSSTRESS_RUNTIME=3000 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes openzfs#5396 Closes openzfs#6522
FransUrbo
pushed a commit
to FransUrbo/zfs
that referenced
this issue
Apr 28, 2019
Refactor dmu_object_alloc_dnsize() and dnode_hold_impl() to simplify the code, fix errors introduced by commit dbeb879 (PR openzfs#6117) interacting badly with large dnodes, and improve performance. * When allocating a new dnode in dmu_object_alloc_dnsize(), update the percpu object ID for the core's metadnode chunk immediately. This eliminates most lock contention when taking the hold and creating the dnode. * Correct detection of the chunk boundary to work properly with large dnodes. * Separate the dmu_hold_impl() code for the FREE case from the code for the ALLOCATED case to make it easier to read. * Fully populate the dnode handle array immediately after reading a block of the metadnode from disk. Subsequently the dnode handle array provides enough information to determine which dnode slots are in use and which are free. * Add several kstats to allow the behavior of the code to be examined. * Verify dnode packing in large_dnode_008_pos.ksh. Since the test is purely creates, it should leave very few holes in the metadnode. * Add test large_dnode_009_pos.ksh, which performs concurrent creates and deletes, to complement existing test which does only creates. With the above fixes, there is very little contention in a test of about 200,000 racing dnode allocations produced by tests 'large_dnode_008_pos' and 'large_dnode_009_pos'. name type data dnode_hold_dbuf_hold 4 0 dnode_hold_dbuf_read 4 0 dnode_hold_alloc_hits 4 3804690 dnode_hold_alloc_misses 4 216 dnode_hold_alloc_interior 4 3 dnode_hold_alloc_lock_retry 4 0 dnode_hold_alloc_lock_misses 4 0 dnode_hold_alloc_type_none 4 0 dnode_hold_free_hits 4 203105 dnode_hold_free_misses 4 4 dnode_hold_free_lock_misses 4 0 dnode_hold_free_lock_retry 4 0 dnode_hold_free_overflow 4 0 dnode_hold_free_refcount 4 57 dnode_hold_free_txg 4 0 dnode_allocate 4 203154 dnode_reallocate 4 0 dnode_buf_evict 4 23918 dnode_alloc_next_chunk 4 4887 dnode_alloc_race 4 0 dnode_alloc_next_block 4 18 The performance is slightly improved for concurrent creates with 16+ threads, and unchanged for low thread counts. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Closes openzfs#5396 Closes openzfs#6522 Closes openzfs#6414 Closes openzfs#6564
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Observed while testing with roughly 100 concurrent dbench threads.
The text was updated successfully, but these errors were encountered: