[LU-14923] do not always take write lock for writable mmap Created: 09/Aug/21 Updated: 09/Aug/21 Resolved: 09/Aug/21 |
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| Status: | Resolved |
| Project: | Lustre |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Improvement | Priority: | Minor |
| Reporter: | Patrick Farrell | Assignee: | Patrick Farrell |
| Resolution: | Not a Bug | Votes: | 0 |
| Labels: | None | ||
| Rank (Obsolete): | 9223372036854775807 |
| Description |
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Currently, Lustre always takes a PW lock when working with a writable mmap. This is not great because it means if multiple nodes map the same file writably and do pure read only, they'll all get write locks. This is pretty easy to fix - just check we are doing a mkwrite when selecting the lock mode. |
| Comments |
| Comment by Patrick Farrell [ 09/Aug/21 ] |
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Well, it looks like I was wrong about this behavior - I picked this up from reading the code but this isn't the actual behavior shown in testing. |