Giuseppe Di Natale 45d1abc74d Improved dnode allocation and dmu_hold_impl() (#6611) ... Refactor dmu_object_alloc_dnsize() and dnode_hold_impl() to simplify the code, fix errors introduced by commit dbeb879 (PR #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>		2017-09-13 15:46:15 -07:00
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linux	Linux 4.13 compat: bio->bi_status and blk_status_t	2017-07-23 19:37:12 -07:00
sys	Improved dnode allocation and dmu_hold_impl() (#6611)	2017-09-13 15:46:15 -07:00
Makefile.am	Kernel header installation should respect --prefix	2014-10-28 09:37:06 -07:00
libnvpair.h	Support custom build directories and move includes	2010-09-08 12:38:56 -07:00
libuutil.h	Support custom build directories and move includes	2010-09-08 12:38:56 -07:00
libuutil_common.h	Support custom build directories and move includes	2010-09-08 12:38:56 -07:00
libuutil_impl.h	Support custom build directories and move includes	2010-09-08 12:38:56 -07:00
libzfs.h	Multi-modifier protection (MMP)	2017-07-13 13:54:00 -04:00
libzfs_core.h	OpenZFS 7600 - zfs rollback should pass target snapshot to kernel	2017-07-04 15:29:52 -07:00
libzfs_impl.h	Multi-modifier protection (MMP)	2017-07-13 13:54:00 -04:00
zfeature_common.h	OpenZFS 2932 - support crash dumps to raidz, etc. pools	2017-04-10 10:24:17 -07:00
zfs_comutil.h	Illumos #2882, #2883, #2900	2013-09-04 15:49:00 -07:00
zfs_deleg.h	Add support for user/group dnode accounting & quota	2016-10-07 09:45:13 -07:00
zfs_fletcher.h	DLPX-44812 integrate EP-220 large memory scalability	2016-11-29 14:34:27 -08:00
zfs_namecheck.h	OpenZFS 7386 - zfs get does not work properly with bookmarks	2017-01-26 14:42:15 -08:00
zfs_prop.h	Check the dataset type more rigorously when fetching properties.	2014-05-06 10:41:46 -07:00
zpios-ctl.h	Fix spelling	2017-01-03 11:31:18 -06:00
zpios-internal.h	Fix spelling	2017-01-03 11:31:18 -06:00