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-rw-r--r--Documentation/block/data-integrity.txt4
-rw-r--r--Documentation/block/deadline-iosched.txt14
2 files changed, 12 insertions, 6 deletions
diff --git a/Documentation/block/data-integrity.txt b/Documentation/block/data-integrity.txt
index e9dc8d86adc7..e8ca040ba2cf 100644
--- a/Documentation/block/data-integrity.txt
+++ b/Documentation/block/data-integrity.txt
@@ -246,7 +246,7 @@ will require extra work due to the application tag.
246 retrieve the tag buffer using bio_integrity_get_tag(). 246 retrieve the tag buffer using bio_integrity_get_tag().
247 247
248 248
2496.3 PASSING EXISTING INTEGRITY METADATA 2495.3 PASSING EXISTING INTEGRITY METADATA
250 250
251 Filesystems that either generate their own integrity metadata or 251 Filesystems that either generate their own integrity metadata or
252 are capable of transferring IMD from user space can use the 252 are capable of transferring IMD from user space can use the
@@ -283,7 +283,7 @@ will require extra work due to the application tag.
283 integrity upon completion. 283 integrity upon completion.
284 284
285 285
2866.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY 2865.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY
287 METADATA 287 METADATA
288 288
289 To enable integrity exchange on a block device the gendisk must be 289 To enable integrity exchange on a block device the gendisk must be
diff --git a/Documentation/block/deadline-iosched.txt b/Documentation/block/deadline-iosched.txt
index c23cab13c3d1..72576769e0f4 100644
--- a/Documentation/block/deadline-iosched.txt
+++ b/Documentation/block/deadline-iosched.txt
@@ -30,12 +30,18 @@ write_expire (in ms)
30Similar to read_expire mentioned above, but for writes. 30Similar to read_expire mentioned above, but for writes.
31 31
32 32
33fifo_batch 33fifo_batch (number of requests)
34---------- 34----------
35 35
36When a read request expires its deadline, we must move some requests from 36Requests are grouped into ``batches'' of a particular data direction (read or
37the sorted io scheduler list to the block device dispatch queue. fifo_batch 37write) which are serviced in increasing sector order. To limit extra seeking,
38controls how many requests we move. 38deadline expiries are only checked between batches. fifo_batch controls the
39maximum number of requests per batch.
40
41This parameter tunes the balance between per-request latency and aggregate
42throughput. When low latency is the primary concern, smaller is better (where
43a value of 1 yields first-come first-served behaviour). Increasing fifo_batch
44generally improves throughput, at the cost of latency variation.
39 45
40 46
41writes_starved (number of dispatches) 47writes_starved (number of dispatches)