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[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>
This commit is contained in:
Arjan van de Ven 2006-01-06 09:46:02 +01:00 committed by Jens Axboe
parent 80cfd548ee
commit 64100099ed
4 changed files with 14 additions and 14 deletions
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16
block/cfq-iosched.c
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@ -25,15 +25,15 @@
/* /*
* tunables * tunables
*/ */
static int cfq_quantum = 4; /* max queue in one round of service */ static const int cfq_quantum = 4; /* max queue in one round of service */
static int cfq_queued = 8; /* minimum rq allocate limit per-queue*/ static const int cfq_queued = 8; /* minimum rq allocate limit per-queue*/
static int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
static int cfq_back_max = 16 * 1024; /* maximum backwards seek, in KiB */ static const 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_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 = HZ / 25;
static int cfq_slice_async_rq = 2; static const int cfq_slice_async_rq = 2;
static int cfq_slice_idle = HZ / 100; static int cfq_slice_idle = HZ / 100;
#define CFQ_IDLE_GRACE (HZ / 10) #define CFQ_IDLE_GRACE (HZ / 10)
@ -45,7 +45,7 @@ static int cfq_slice_idle = HZ / 100;
/* /*
* disable queueing at the driver/hardware level * 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 * for the hash of cfqq inside the cfqd

8
block/deadline-iosched.c
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@ -19,10 +19,10 @@
/* /*
* See Documentation/block/deadline-iosched.txt * See Documentation/block/deadline-iosched.txt
*/ */
static int read_expire = HZ / 2; /* max time before a read is submitted. */ static const 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 const 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 const 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 fifo_batch = 16; /* # of sequential requests treated as one
by the above parameters. For throughput. */ by the above parameters. For throughput. */
static const int deadline_hash_shift = 5; static const int deadline_hash_shift = 5;

2
block/ll_rw_blk.c
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@ -1039,7 +1039,7 @@ void blk_queue_invalidate_tags(request_queue_t *q)
EXPORT_SYMBOL(blk_queue_invalidate_tags); EXPORT_SYMBOL(blk_queue_invalidate_tags);
static char *rq_flags[] = { static const char * const rq_flags[] = {
"REQ_RW", "REQ_RW",
"REQ_FAILFAST", "REQ_FAILFAST",
"REQ_SORTED", "REQ_SORTED",

2
block/scsi_ioctl.c
View File

@ -46,7 +46,7 @@ EXPORT_SYMBOL(scsi_command_size);
static int sg_get_version(int __user *p) 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); return put_user(sg_version_num, p);
} }