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| author | Mike Christie <michaelc@cs.wisc.edu> | 2006-03-08 11:19:51 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@nelson.home.kernel.dk> | 2006-03-27 09:29:01 +0200 |
| commit | 28832e83379afd0b0e83b78ac317290c79ebd496 (patch) | |
| tree | 5b6acaed05134e0558f08546aca99d74d30f97e9 /Documentation/block/biodoc.txt | |
| parent | 5d5d7727a8cde78f798ecf04bac8031eff536f9d (diff) | |
| download | lwn-28832e83379afd0b0e83b78ac317290c79ebd496.tar.gz lwn-28832e83379afd0b0e83b78ac317290c79ebd496.zip | |
[PATCH] update max_sectors documentation
The max_sectors has been split into max_hw_sectors and max_sectors for some
time. A patch to have blk_queue_max_sectors enforce this was sent by
me and it broke IDE. This patch updates the documentation.
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'Documentation/block/biodoc.txt')
| -rw-r--r-- | Documentation/block/biodoc.txt | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 8e63831971d5..f989a9e839b4 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -132,8 +132,18 @@ Some new queue property settings: limit. No highmem default. blk_queue_max_sectors(q, max_sectors) - Maximum size request you can handle in units of 512 byte - sectors. 255 default. + Sets two variables that limit the size of the request. + + - The request queue's max_sectors, which is a soft size in + in units of 512 byte sectors, and could be dynamically varied + by the core kernel. + + - The request queue's max_hw_sectors, which is a hard limit + and reflects the maximum size request a driver can handle + in units of 512 byte sectors. + + The default for both max_sectors and max_hw_sectors is + 255. The upper limit of max_sectors is 1024. blk_queue_max_phys_segments(q, max_segments) Maximum physical segments you can handle in a request. 128 |