diff options
Diffstat (limited to 'Documentation/block')
| -rw-r--r-- | Documentation/block/biodoc.txt | 9 | ||||
| -rw-r--r-- | Documentation/block/queue-sysfs.txt | 10 |
2 files changed, 9 insertions, 10 deletions
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index b9a83dd2473..c6d84cfd2f5 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -497,7 +497,7 @@ The scatter gather list is in the form of an array of <page, offset, len> entries with their corresponding dma address mappings filled in at the appropriate time. As an optimization, contiguous physical pages can be covered by a single entry where <page> refers to the first page and <len> -covers the range of pages (upto 16 contiguous pages could be covered this +covers the range of pages (up to 16 contiguous pages could be covered this way). There is a helper routine (blk_rq_map_sg) which drivers can use to build the sg list. @@ -565,7 +565,7 @@ struct request { . int tag; /* command tag associated with request */ void *special; /* same as before */ - char *buffer; /* valid only for low memory buffers upto + char *buffer; /* valid only for low memory buffers up to current_nr_sectors */ . . @@ -963,11 +963,6 @@ elevator_dispatch_fn* fills the dispatch queue with ready requests. elevator_add_req_fn* called to add a new request into the scheduler -elevator_queue_empty_fn returns true if the merge queue is empty. - Drivers shouldn't use this, but rather check - if elv_next_request is NULL (without losing the - request if one exists!) - elevator_former_req_fn elevator_latter_req_fn These return the request before or after the one specified in disk sort order. Used by the diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index f65274081c8..d8147b336c3 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -45,9 +45,13 @@ device. rq_affinity (RW) ---------------- -If this option is enabled, the block layer will migrate request completions -to the CPU that originally submitted the request. For some workloads -this provides a significant reduction in CPU cycles due to caching effects. +If this option is '1', the block layer will migrate request completions to the +cpu "group" that originally submitted the request. For some workloads this +provides a significant reduction in CPU cycles due to caching effects. + +For storage configurations that need to maximize distribution of completion +processing setting this option to '2' forces the completion to run on the +requesting cpu (bypassing the "group" aggregation logic). scheduler (RW) -------------- |