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authorArjan van de Ven <arjan@infradead.org>2006-01-06 09:46:02 +0100
committerJens Axboe <axboe@suse.de>2006-01-06 09:46:02 +0100
commit64100099ed22f71cce656c5c2caecf5c9cf255dc (patch)
treef6ebf7c94ee2eeb080d25880ffca839ec39ec47e /block
parent80cfd548eed68cf90c5ae9cfcd6b02230cece756 (diff)
downloadtalos-op-linux-64100099ed22f71cce656c5c2caecf5c9cf255dc.tar.gz
talos-op-linux-64100099ed22f71cce656c5c2caecf5c9cf255dc.zip
[BLOCK] mark some block/ variables cons
the patch below marks various read-only variables in block/* as const, so that gcc can optimize the use of them; eg gcc will replace the use by the value directly now and will even remove the memory usage of these. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'block')
-rw-r--r--block/cfq-iosched.c16
-rw-r--r--block/deadline-iosched.c8
-rw-r--r--block/ll_rw_blk.c2
-rw-r--r--block/scsi_ioctl.c2
4 files changed, 14 insertions, 14 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ee0bb41694b0..74fae2daf87e 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -25,15 +25,15 @@
/*
* tunables
*/
-static int cfq_quantum = 4; /* max queue in one round of service */
-static int cfq_queued = 8; /* minimum rq allocate limit per-queue*/
-static int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
-static int cfq_back_max = 16 * 1024; /* maximum backwards seek, in KiB */
-static int cfq_back_penalty = 2; /* penalty of a backwards seek */
+static const int cfq_quantum = 4; /* max queue in one round of service */
+static const int cfq_queued = 8; /* minimum rq allocate limit per-queue*/
+static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
+static const int cfq_back_max = 16 * 1024; /* maximum backwards seek, in KiB */
+static const int cfq_back_penalty = 2; /* penalty of a backwards seek */
-static int cfq_slice_sync = HZ / 10;
+static const int cfq_slice_sync = HZ / 10;
static int cfq_slice_async = HZ / 25;
-static int cfq_slice_async_rq = 2;
+static const int cfq_slice_async_rq = 2;
static int cfq_slice_idle = HZ / 100;
#define CFQ_IDLE_GRACE (HZ / 10)
@@ -45,7 +45,7 @@ static int cfq_slice_idle = HZ / 100;
/*
* disable queueing at the driver/hardware level
*/
-static int cfq_max_depth = 2;
+static const int cfq_max_depth = 2;
/*
* for the hash of cfqq inside the cfqd
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index 9cbec09e8415..27e494b1bf97 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -19,10 +19,10 @@
/*
* See Documentation/block/deadline-iosched.txt
*/
-static int read_expire = HZ / 2; /* max time before a read is submitted. */
-static int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
-static int writes_starved = 2; /* max times reads can starve a write */
-static int fifo_batch = 16; /* # of sequential requests treated as one
+static const int read_expire = HZ / 2; /* max time before a read is submitted. */
+static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
+static const int writes_starved = 2; /* max times reads can starve a write */
+static const int fifo_batch = 16; /* # of sequential requests treated as one
by the above parameters. For throughput. */
static const int deadline_hash_shift = 5;
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 97f4e7ecedfe..e02c88ca8fb5 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1039,7 +1039,7 @@ void blk_queue_invalidate_tags(request_queue_t *q)
EXPORT_SYMBOL(blk_queue_invalidate_tags);
-static char *rq_flags[] = {
+static const char * const rq_flags[] = {
"REQ_RW",
"REQ_FAILFAST",
"REQ_SORTED",
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 1d8852f7bbff..c2ac36dfe4f3 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -46,7 +46,7 @@ EXPORT_SYMBOL(scsi_command_size);
static int sg_get_version(int __user *p)
{
- static int sg_version_num = 30527;
+ static const int sg_version_num = 30527;
return put_user(sg_version_num, p);
}
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