[LU-4793] CLIO per-page allocations use size-1024 slab Created: 20/Mar/14 Updated: 08/Sep/14 Resolved: 11/Jun/14 |
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| Status: | Resolved |
| Project: | Lustre |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | Lustre 2.6.0 |
| Type: | Bug | Priority: | Critical |
| Reporter: | Andreas Dilger | Assignee: | Jinshan Xiong (Inactive) |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Severity: | 3 |
| Rank (Obsolete): | 13192 |
| Description |
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Running some simple read and write tests using "dd" to large files I see a huge amount of memory allocated by the size-1024 slab - about 1/4 if all RAM of the system. The size of the per-page allocation must be reduced in some manner, since this is far to much memory wasted for CLIO overhead. |
| Comments |
| Comment by Jinshan Xiong (Inactive) [ 23/Apr/14 ] |
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The size of cl_page is now 584 bytes. A cl_page is composed of the following sub pages: ccc_page(88 bytes), lov_page(56 bytes), lovsub_page(48 bytes), and osc_page(232 bytes). In osc_page, it has an embedded osc_async_page which is 120 bytes. I think the short term target is to shrink the cl_page down to below 512 bytes so that it can fit into size-512 slab. |
| Comment by Jinshan Xiong (Inactive) [ 23/Apr/14 ] |
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patch is at: http://review.whamcloud.com/10070 |
| Comment by Andreas Dilger [ 05/Jun/14 ] |
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Increase priority to critical so that patch will be tracked for landing in 2.6.0. |
| Comment by Jodi Levi (Inactive) [ 11/Jun/14 ] |
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Patch landed to Master. |