[LU-17090] ladvise willread and OSD cache Created: 05/Sep/23 Updated: 05/Sep/23 |
|
| Status: | Open |
| Project: | Lustre |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Improvement | Priority: | Minor |
| Reporter: | Patrick Farrell | Assignee: | Patrick Farrell |
| Resolution: | Unresolved | Votes: | 0 |
| Labels: | None | ||
| Severity: | 3 |
| Rank (Obsolete): | 9223372036854775807 |
| Description |
|
Today, when WILLREAD advise is given, ladvise_prefetch reads in to the thread big cache. If this cache is not page cache pages, this is a waste of time, since it's not used for subsequent reads. We should just not do anything if the buffer is not from the page cache.
Note that compression will also use this, so we'll also need an option to force reads to a local buffer. |
| Comments |
| Comment by Patrick Farrell [ 05/Sep/23 ] |
|
This is pretty minor, I just wanted to note this. It's just a case where WILLREAD will waste effort on the server if the page cache is being bypassed. Worth fixing but not serious. |