From 6a421c1dc94b12923294a359822346f12492de5e Mon Sep 17 00:00:00 2001 From: Aaron Carroll Date: Thu, 14 Aug 2008 18:17:15 +1000 Subject: block: update documentation for deadline fifo_batch tunable Update the description of fifo_batch to match the current implementation, and include a description of how to tune it. Signed-off-by: Aaron Carroll Signed-off-by: Jens Axboe --- Documentation/block/deadline-iosched.txt | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/block/deadline-iosched.txt b/Documentation/block/deadline-iosched.txt index c23cab13c3d..72576769e0f 100644 --- a/Documentation/block/deadline-iosched.txt +++ b/Documentation/block/deadline-iosched.txt @@ -30,12 +30,18 @@ write_expire (in ms) Similar to read_expire mentioned above, but for writes. -fifo_batch +fifo_batch (number of requests) ---------- -When a read request expires its deadline, we must move some requests from -the sorted io scheduler list to the block device dispatch queue. fifo_batch -controls how many requests we move. +Requests are grouped into ``batches'' of a particular data direction (read or +write) which are serviced in increasing sector order. To limit extra seeking, +deadline expiries are only checked between batches. fifo_batch controls the +maximum number of requests per batch. + +This parameter tunes the balance between per-request latency and aggregate +throughput. When low latency is the primary concern, smaller is better (where +a value of 1 yields first-come first-served behaviour). Increasing fifo_batch +generally improves throughput, at the cost of latency variation. writes_starved (number of dispatches) -- cgit v1.2.3 From 710027a48ede75428cc68eaa8ae2269b1e356e2c Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Tue, 19 Aug 2008 20:13:11 +0200 Subject: Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. Signed-off-by: Randy Dunlap Signed-off-by: Jens Axboe --- Documentation/DocBook/kernel-api.tmpl | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index b7b1482f6e0..f5696ba9ae9 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -364,6 +364,10 @@ X!Edrivers/pnp/system.c !Eblock/blk-barrier.c !Eblock/blk-tag.c !Iblock/blk-tag.c +!Eblock/blk-integrity.c +!Iblock/blktrace.c +!Iblock/genhd.c +!Eblock/genhd.c -- cgit v1.2.3 From 79eb014578b79fcfb9d9e7dc979d1316079220aa Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Thu, 18 Sep 2008 09:35:28 -0700 Subject: fix an example of scatterlists handling in DMA-API.txt This example isn't the proper way to handle scatterlists (can't handle sg chaining). Signed-off-by: FUJITA Tomonori Signed-off-by: Jens Axboe --- Documentation/DMA-API.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index d8b63d164e4..b8e86460046 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -337,7 +337,7 @@ With scatterlists, you use the resulting mapping like this: int i, count = dma_map_sg(dev, sglist, nents, direction); struct scatterlist *sg; - for (i = 0, sg = sglist; i < count; i++, sg++) { + for_each_sg(sglist, sg, count, i) { hw_address[i] = sg_dma_address(sg); hw_len[i] = sg_dma_len(sg); } -- cgit v1.2.3 From b911e473d24633c19414b54b82b9ff0b1a2419d7 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 10 Oct 2008 08:22:44 +0200 Subject: doc/cdrom: Trvial documentation error, file not present The sbpcd tester program is not included in the kernel source tree, so remove the reference to it. Signed-off-by: Randy Dunlap Reported-by: Nick Warne Signed-off-by: Jens Axboe --- Documentation/cdrom/ide-cd | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/cdrom/ide-cd b/Documentation/cdrom/ide-cd index 91c0dcc6fa5..2c558cd6c1e 100644 --- a/Documentation/cdrom/ide-cd +++ b/Documentation/cdrom/ide-cd @@ -145,8 +145,7 @@ useful for reading photocds. To play an audio CD, you should first unmount and remove any data CDROM. Any of the CDROM player programs should then work (workman, -workbone, cdplayer, etc.). Lacking anything else, you could use the -cdtester program in Documentation/cdrom/sbpcd. +workbone, cdplayer, etc.). On a few drives, you can read digital audio directly using a program such as cdda2wav. The only types of drive which I've heard support -- cgit v1.2.3