#3689 closed enhancement (fixed)
bdbuf: Replace automatic read-ahead with rtems_bdbuf_peek()
Reported by: | Sebastian Huber | Owned by: | Sebastian Huber |
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Priority: | normal | Milestone: | 6.1 |
Component: | lib/block | Version: | 5 |
Severity: | normal | Keywords: | |
Cc: | Blocked By: | ||
Blocking: |
Description
The block device cache (bdbuf) tries to deduce a read ahead opportunity from the read access pattern. Using real world FAT file systems showed that this is not very reliable and the read ahead seldom happens. One way to fix this issue is let file systems give a hint to the block device cache that they will likely read a certain block in the future, e.g. the next block in a sequential file read. Remove the existing read ahead logic and add a new function rtems_bdbuf_peek() instead.
Attachments (1)
Change History (8)
Changed on 02/11/19 at 10:49:48 by Sebastian Huber
Attachment: | 0001-FIXME-bdbuf-Add-rtems_bdbuf_peek.patch added |
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comment:1 Changed on 02/11/19 at 11:03:03 by Chris Johns
Why is the status returned from the peek in fat_file_read
not checked?
comment:2 Changed on 02/11/19 at 11:04:30 by Sebastian Huber
The data is not used yet. It is just a hint, maybe we should remove a return code from rtems_bdbuf_peek().
comment:3 Changed on 02/11/19 at 11:09:51 by Chris Johns
I would not remove the return code, it may be used in another file system.
comment:4 Changed on 12/19/19 at 08:07:34 by Sebastian Huber
Milestone: | 5.1 → 6.1 |
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comment:5 Changed on 03/26/21 at 13:28:22 by Christian Mauderer <christian.mauderer@…>
In 6ae79e6/rtems:
comment:6 Changed on 03/26/21 at 13:28:26 by Christian Mauderer <christian.mauderer@…>
Resolution: | → fixed |
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Status: | assigned → closed |
In fd639b8/rtems:
Prototoype implementation.