[LU-9782] High CPU usage with random IO test. Created: 19/Jul/17 Updated: 26/Oct/17 Resolved: 24/Oct/17 |
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| Status: | Resolved |
| Project: | Lustre |
| Component/s: | None |
| Affects Version/s: | Lustre 2.7.0, Lustre 2.8.0, Lustre 2.9.0, Lustre 2.10.0 |
| Fix Version/s: | Lustre 2.11.0, Lustre 2.10.2 |
| Type: | Bug | Priority: | Critical |
| Reporter: | Alexey Lyashkov | Assignee: | WC Triage |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | ldiskfs | ||
| Environment: |
any lustre with commit 144b5a65c16, and likely before. |
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| Issue Links: |
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| Severity: | 3 | ||||
| Rank (Obsolete): | 9223372036854775807 | ||||
| Description |
|
osd-ldiskfs have a several osd_is_mapped calls when extent tree scanned to get decission about error for rewrite case. But extent tree is huge with while random io write test and search is CPU expensive in this case. typical perf output is |--75.99%-- rb_next
| |
| |--94.49%-- ldiskfs_es_find_delayed_extent_range
| | ldiskfs_fiemap
| | osd_is_mapped
| | osd_declare_write_commit
| | ofd_commitrw_write.isra.32
| | ofd_commitrw
| | obd_commitrw.constprop.39
| | tgt_brw_write
| | tgt_request_handle
| | ptlrpc_server_handle_request
| | ptlrpc_main
| | kthread
| | ret_from_fork
| |
| |--5.49%-- ldiskfs_fiemap
| | osd_is_mapped
| | osd_declare_write_commit
| | ofd_commitrw_write.isra.32
| | ofd_commitrw
| | obd_commitrw.constprop.39
| | tgt_brw_write
| | tgt_request_handle
| | ptlrpc_server_handle_request
| | ptlrpc_main
| | kthread
| | ret_from_fork
| --0.02%-- [...]
|
|--21.80%-- ldiskfs_es_find_delayed_extent_range
| |
| |--100.00%-- ldiskfs_fiemap
| | osd_is_mapped
| | osd_declare_write_commit
| | ofd_commitrw_write.isra.32
| | ofd_commitrw
| | obd_commitrw.constprop.39
| | tgt_brw_write
| | tgt_request_handle
| | ptlrpc_server_handle_request
| | ptlrpc_main
| | kthread
| | ret_from_fork
| --0.00%-- [...]
avoid second search by caching result on hight bits of lnb_flags which not used in wire increase a performance dramatically
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| Comments |
| Comment by Gerrit Updater [ 20/Jul/17 ] |
|
Parinay Kondekar (parinay.kondekar@seagate.com) uploaded a new patch: https://review.whamcloud.com/28145 |
| Comment by Gerrit Updater [ 24/Oct/17 ] |
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Oleg Drokin (oleg.drokin@intel.com) merged in patch https://review.whamcloud.com/28145/ |
| Comment by Peter Jones [ 24/Oct/17 ] |
|
Landed for 2.11 |
| Comment by Gerrit Updater [ 24/Oct/17 ] |
|
Minh Diep (minh.diep@intel.com) uploaded a new patch: https://review.whamcloud.com/29739 |
| Comment by Gerrit Updater [ 26/Oct/17 ] |
|
John L. Hammond (john.hammond@intel.com) merged in patch https://review.whamcloud.com/29739/ |