[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>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ee0bb41..74fae2d 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 @@
/*
* 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