Eric Lee / linux-smarc-t335x-v3.2

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Commit 64100099ed22f71cce656c5c2caecf5c9cf255dc

Authored by Arjan van de Ven
Committed by Jens Axboe
1 parent 80cfd548ee
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

[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>

Showing 4 changed files with 14 additions and 14 deletions Side-by-side Diff

... ... @@ -25,15 +25,15 @@
25 25 /*
26 26 * tunables
27 27 */
28   -static int cfq_quantum = 4; /* max queue in one round of service */
29   -static int cfq_queued = 8; /* minimum rq allocate limit per-queue*/
30   -static int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
31   -static int cfq_back_max = 16 * 1024; /* maximum backwards seek, in KiB */
32   -static int cfq_back_penalty = 2; /* penalty of a backwards seek */
  28 +static const int cfq_quantum = 4; /* max queue in one round of service */
  29 +static const int cfq_queued = 8; /* minimum rq allocate limit per-queue*/
  30 +static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
  31 +static const int cfq_back_max = 16 * 1024; /* maximum backwards seek, in KiB */
  32 +static const int cfq_back_penalty = 2; /* penalty of a backwards seek */
33 33  
34   -static int cfq_slice_sync = HZ / 10;
  34 +static const int cfq_slice_sync = HZ / 10;
35 35 static int cfq_slice_async = HZ / 25;
36   -static int cfq_slice_async_rq = 2;
  36 +static const int cfq_slice_async_rq = 2;
37 37 static int cfq_slice_idle = HZ / 100;
38 38  
39 39 #define CFQ_IDLE_GRACE (HZ / 10)
... ... @@ -45,7 +45,7 @@
45 45 /*
46 46 * disable queueing at the driver/hardware level
47 47 */
48   -static int cfq_max_depth = 2;
  48 +static const int cfq_max_depth = 2;
49 49  
50 50 /*
51 51 * for the hash of cfqq inside the cfqd
block/deadline-iosched.c
Diff comments   View file @ 6410009
... ... @@ -19,10 +19,10 @@
19 19 /*
20 20 * See Documentation/block/deadline-iosched.txt
21 21 */
22   -static int read_expire = HZ / 2; /* max time before a read is submitted. */
23   -static int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
24   -static int writes_starved = 2; /* max times reads can starve a write */
25   -static int fifo_batch = 16; /* # of sequential requests treated as one
  22 +static const int read_expire = HZ / 2; /* max time before a read is submitted. */
  23 +static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
  24 +static const int writes_starved = 2; /* max times reads can starve a write */
  25 +static const int fifo_batch = 16; /* # of sequential requests treated as one
26 26 by the above parameters. For throughput. */
27 27  
28 28 static const int deadline_hash_shift = 5;
... ... @@ -1039,7 +1039,7 @@
1039 1039  
1040 1040 EXPORT_SYMBOL(blk_queue_invalidate_tags);
1041 1041  
1042   -static char *rq_flags[] = {
  1042 +static const char * const rq_flags[] = {
1043 1043 "REQ_RW",
1044 1044 "REQ_FAILFAST",
1045 1045 "REQ_SORTED",
... ... @@ -46,7 +46,7 @@
46 46  
47 47 static int sg_get_version(int __user *p)
48 48 {
49   - static int sg_version_num = 30527;
  49 + static const int sg_version_num = 30527;
50 50 return put_user(sg_version_num, p);
51 51 }
52 52