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authorTejun Heo <htejun@gmail.com>2006-01-06 03:58:37 -0500
committerJens Axboe <axboe@suse.de>2006-01-06 03:58:37 -0500
commitff5b8cf1491330836d75eede4e5632caa32b776a (patch)
tree4bb6d0fea6922d139f989da12231661149082b22
parent3e087b575496b8aa445192f58e7d996b1cdfa121 (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>
-rw-r--r--Documentation/block/biodoc.txt10
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.
263The generic i/o scheduler would make sure that it places the barrier request and 263The generic i/o scheduler would make sure that it places the barrier request and
264all other requests coming after it after all the previous requests in the 264all other requests coming after it after all the previous requests in the
265queue. Barriers may be implemented in different ways depending on the 265queue. Barriers may be implemented in different ways depending on the
266driver. A SCSI driver for example could make use of ordered tags to 266driver. For more details regarding I/O barriers, please read barrier.txt
267preserve the necessary ordering with a lower impact on throughput. For IDE 267in this directory.
268this might be two sync cache flush: a pre and post flush when encountering
269a barrier write.
270
271There is a provision for queues to indicate what kind of barriers they
272can provide. This is as of yet unmerged, details will be added here once it
273is in the kernel.
274 268
2751.2.2 Request Priority/Latency 2691.2.2 Request Priority/Latency
276 270