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author | Tejun Heo <htejun@gmail.com> | 2006-01-06 03:58:37 -0500 |
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committer | Jens Axboe <axboe@suse.de> | 2006-01-06 03:58:37 -0500 |
commit | ff5b8cf1491330836d75eede4e5632caa32b776a (patch) | |
tree | 4bb6d0fea6922d139f989da12231661149082b22 /Documentation/block/biodoc.txt | |
parent | 3e087b575496b8aa445192f58e7d996b1cdfa121 (diff) |
[BLOCK] I/O barrier documentation update
Update documentation to match new barrier implementation.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'Documentation/block/biodoc.txt')
-rw-r--r-- | Documentation/block/biodoc.txt | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 303c57a7fad9..8e63831971d5 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt | |||
@@ -263,14 +263,8 @@ A flag in the bio structure, BIO_BARRIER is used to identify a barrier i/o. | |||
263 | The generic i/o scheduler would make sure that it places the barrier request and | 263 | The generic i/o scheduler would make sure that it places the barrier request and |
264 | all other requests coming after it after all the previous requests in the | 264 | all other requests coming after it after all the previous requests in the |
265 | queue. Barriers may be implemented in different ways depending on the | 265 | queue. Barriers may be implemented in different ways depending on the |
266 | driver. A SCSI driver for example could make use of ordered tags to | 266 | driver. For more details regarding I/O barriers, please read barrier.txt |
267 | preserve the necessary ordering with a lower impact on throughput. For IDE | 267 | in this directory. |
268 | this might be two sync cache flush: a pre and post flush when encountering | ||
269 | a barrier write. | ||
270 | |||
271 | There is a provision for queues to indicate what kind of barriers they | ||
272 | can provide. This is as of yet unmerged, details will be added here once it | ||
273 | is in the kernel. | ||
274 | 268 | ||
275 | 1.2.2 Request Priority/Latency | 269 | 1.2.2 Request Priority/Latency |
276 | 270 | ||