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authorLinus Torvalds <torvalds@linux-foundation.org>2009-02-02 19:19:50 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-02-02 19:19:50 -0800
commit86adf8adfcb3d3f4b6c30aeb40da480da02de1d1 (patch)
tree87800568dc48006f3418689e4d23578f5c1d79b7
parent3fff0179e33cd7d0a688dab65700c46ad089e934 (diff)
parentcbb5901b904e122139e97c6f4caed9b1f13c3455 (diff)
downloadop-kernel-dev-86adf8adfcb3d3f4b6c30aeb40da480da02de1d1.zip
op-kernel-dev-86adf8adfcb3d3f4b6c30aeb40da480da02de1d1.tar.gz
Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: add text file detailing queue/ sysfs files bio.h: If they MUST be inlined, then use __always_inline Fix misleading comment in bio.h block: fix inconsistent parenthesisation of QUEUE_FLAG_DEFAULT block: fix oops in blk_queue_io_stat()
-rw-r--r--Documentation/block/queue-sysfs.txt63
-rw-r--r--block/blk-core.c6
-rw-r--r--block/blk.h8
-rw-r--r--include/linux/bio.h10
-rw-r--r--include/linux/blkdev.h2
5 files changed, 81 insertions, 8 deletions
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
new file mode 100644
index 0000000..e164403
--- /dev/null
+++ b/Documentation/block/queue-sysfs.txt
@@ -0,0 +1,63 @@
+Queue sysfs files
+=================
+
+This text file will detail the queue files that are located in the sysfs tree
+for each block device. Note that stacked devices typically do not export
+any settings, since their queue merely functions are a remapping target.
+These files are the ones found in the /sys/block/xxx/queue/ directory.
+
+Files denoted with a RO postfix are readonly and the RW postfix means
+read-write.
+
+hw_sector_size (RO)
+-------------------
+This is the hardware sector size of the device, in bytes.
+
+max_hw_sectors_kb (RO)
+----------------------
+This is the maximum number of kilobytes supported in a single data transfer.
+
+max_sectors_kb (RW)
+-------------------
+This is the maximum number of kilobytes that the block layer will allow
+for a filesystem request. Must be smaller than or equal to the maximum
+size allowed by the hardware.
+
+nomerges (RW)
+-------------
+This enables the user to disable the lookup logic involved with IO merging
+requests in the block layer. Merging may still occur through a direct
+1-hit cache, since that comes for (almost) free. The IO scheduler will not
+waste cycles doing tree/hash lookups for merges if nomerges is 1. Defaults
+to 0, enabling all merges.
+
+nr_requests (RW)
+----------------
+This controls how many requests may be allocated in the block layer for
+read or write requests. Note that the total allocated number may be twice
+this amount, since it applies only to reads or writes (not the accumulated
+sum).
+
+read_ahead_kb (RW)
+------------------
+Maximum number of kilobytes to read-ahead for filesystems on this block
+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.
+
+scheduler (RW)
+--------------
+When read, this file will display the current and available IO schedulers
+for this block device. The currently active IO scheduler will be enclosed
+in [] brackets. Writing an IO scheduler name to this file will switch
+control of this block device to that new IO scheduler. Note that writing
+an IO scheduler name to this file will attempt to load that IO scheduler
+module, if it isn't already present in the system.
+
+
+
+Jens Axboe <jens.axboe@oracle.com>, February 2009
diff --git a/block/blk-core.c b/block/blk-core.c
index ca69f3d..29bcfac 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -69,7 +69,7 @@ static void drive_stat_acct(struct request *rq, int new_io)
int rw = rq_data_dir(rq);
int cpu;
- if (!blk_fs_request(rq) || !disk || !blk_queue_io_stat(disk->queue))
+ if (!blk_fs_request(rq) || !disk || !blk_do_io_stat(disk->queue))
return;
cpu = part_stat_lock();
@@ -1667,7 +1667,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
{
struct gendisk *disk = req->rq_disk;
- if (!disk || !blk_queue_io_stat(disk->queue))
+ if (!disk || !blk_do_io_stat(disk->queue))
return;
if (blk_fs_request(req)) {
@@ -1686,7 +1686,7 @@ static void blk_account_io_done(struct request *req)
{
struct gendisk *disk = req->rq_disk;
- if (!disk || !blk_queue_io_stat(disk->queue))
+ if (!disk || !blk_do_io_stat(disk->queue))
return;
/*
diff --git a/block/blk.h b/block/blk.h
index 6e1ed40..0dce92c 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -108,4 +108,12 @@ static inline int blk_cpu_to_group(int cpu)
#endif
}
+static inline int blk_do_io_stat(struct request_queue *q)
+{
+ if (q)
+ return blk_queue_io_stat(q);
+
+ return 0;
+}
+
#endif
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 0942765..2aa283a 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -451,12 +451,13 @@ extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
#ifdef CONFIG_HIGHMEM
/*
- * remember to add offset! and never ever reenable interrupts between a
- * bvec_kmap_irq and bvec_kunmap_irq!!
+ * remember never ever reenable interrupts between a bvec_kmap_irq and
+ * bvec_kunmap_irq!
*
* This function MUST be inlined - it plays with the CPU interrupt flags.
*/
-static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
+static __always_inline char *bvec_kmap_irq(struct bio_vec *bvec,
+ unsigned long *flags)
{
unsigned long addr;
@@ -472,7 +473,8 @@ static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
return (char *) addr + bvec->bv_offset;
}
-static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
+static __always_inline void bvec_kunmap_irq(char *buffer,
+ unsigned long *flags)
{
unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d08c4b8..dcaa0fd 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -455,7 +455,7 @@ struct request_queue
#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
(1 << QUEUE_FLAG_CLUSTER) | \
- 1 << QUEUE_FLAG_STACKABLE)
+ (1 << QUEUE_FLAG_STACKABLE))
static inline int queue_is_locked(struct request_queue *q)
{
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