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Date: Sun, 9 Mar 2008 18:10:31 +0100
From: Borislav Petkov <petkovbb@...glemail.com>
To: <bzolnier@...il.com>
Cc: linux-kernel@...r.kernel.org, linux-ide@...r.kernel.org,
Borislav Petkov <petkovbb@...il.com>
Subject: [PATCH 3/4] ide-tape remove pipeline speed/control calculations
Pipeline handling calculations in idetape_calculate_speeds() can
go since they do not have any effect on other functionality besides:
1. info is only being exported through /proc as a read-only item
(controlled_pipeline_head_speed, uncontrolled_pipeline_head_speed)
2. used in idetape_restart_speed_control() which, in turn, is unrelated to
other code
3. used only for pipeline frames number accounting (tape->pipeline_head),
also unused elsewhere.
4.some variables are:
only written to: tape->buffer_head;
unused: tape->tape_head, tape->last_tape_head
Signed-off-by: Borislav Petkov <petkovbb@...il.com>
---
drivers/ide/ide-tape.c | 131 ------------------------------------------------
1 files changed, 0 insertions(+), 131 deletions(-)
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 46a5f95..a06d83f 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -84,9 +84,6 @@ enum {
* We start from MIN maximum stages (we will not even use MIN stages if we don't
* need them), increment it by RATE*(MAX-MIN) whenever we sense that the
* pipeline is empty, until we reach the optimum value or until we reach MAX.
- *
- * Setting the following parameter to 0 is illegal: the pipelined mode cannot be
- * disabled (idetape_calculate_speeds() divides by tape->max_stages.)
*/
#define IDETAPE_MIN_PIPELINE_STAGES 1
#define IDETAPE_MAX_PIPELINE_STAGES 400
@@ -392,39 +389,12 @@ typedef struct ide_tape_obj {
*/
int postpone_cnt;
- /*
- * Measures number of frames:
- *
- * 1. written/read to/from the driver pipeline (pipeline_head).
- * 2. written/read to/from the tape buffers (idetape_bh).
- * 3. written/read by the tape to/from the media (tape_head).
- */
- int pipeline_head;
- int buffer_head;
- int tape_head;
- int last_tape_head;
-
/* Speed control at the tape buffers input/output */
unsigned long insert_time;
int insert_size;
int insert_speed;
- int max_insert_speed;
int measure_insert_time;
- /* Speed regulation negative feedback loop */
- int speed_control;
- int pipeline_head_speed;
- int controlled_pipeline_head_speed;
- int uncontrolled_pipeline_head_speed;
- int controlled_last_pipeline_head;
- unsigned long uncontrolled_pipeline_head_time;
- unsigned long controlled_pipeline_head_time;
- int controlled_previous_pipeline_head;
- int uncontrolled_previous_pipeline_head;
- unsigned long controlled_previous_head_time;
- unsigned long uncontrolled_previous_head_time;
- int restart_speed_control_req;
-
u32 debug_mask;
} idetape_tape_t;
@@ -1333,69 +1303,6 @@ static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
pc->idetape_callback = &idetape_pc_callback;
}
-static void idetape_calculate_speeds(ide_drive_t *drive)
-{
- idetape_tape_t *tape = drive->driver_data;
-
- if (time_after(jiffies,
- tape->controlled_pipeline_head_time + 120 * HZ)) {
- tape->controlled_previous_pipeline_head =
- tape->controlled_last_pipeline_head;
- tape->controlled_previous_head_time =
- tape->controlled_pipeline_head_time;
- tape->controlled_last_pipeline_head = tape->pipeline_head;
- tape->controlled_pipeline_head_time = jiffies;
- }
- if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
- tape->controlled_pipeline_head_speed = (tape->pipeline_head -
- tape->controlled_last_pipeline_head) * 32 * HZ /
- (jiffies - tape->controlled_pipeline_head_time);
- else if (time_after(jiffies, tape->controlled_previous_head_time))
- tape->controlled_pipeline_head_speed = (tape->pipeline_head -
- tape->controlled_previous_pipeline_head) * 32 *
- HZ / (jiffies - tape->controlled_previous_head_time);
-
- if (tape->nr_pending_stages < tape->max_stages/*- 1 */) {
- /* -1 for read mode error recovery */
- if (time_after(jiffies, tape->uncontrolled_previous_head_time +
- 10 * HZ)) {
- tape->uncontrolled_pipeline_head_time = jiffies;
- tape->uncontrolled_pipeline_head_speed =
- (tape->pipeline_head -
- tape->uncontrolled_previous_pipeline_head) *
- 32 * HZ / (jiffies -
- tape->uncontrolled_previous_head_time);
- }
- } else {
- tape->uncontrolled_previous_head_time = jiffies;
- tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
- if (time_after(jiffies, tape->uncontrolled_pipeline_head_time +
- 30 * HZ))
- tape->uncontrolled_pipeline_head_time = jiffies;
-
- }
- tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed,
- tape->controlled_pipeline_head_speed);
-
- if (tape->speed_control == 1) {
- if (tape->nr_pending_stages >= tape->max_stages / 2)
- tape->max_insert_speed = tape->pipeline_head_speed +
- (1100 - tape->pipeline_head_speed) * 2 *
- (tape->nr_pending_stages - tape->max_stages / 2)
- / tape->max_stages;
- else
- tape->max_insert_speed = 500 +
- (tape->pipeline_head_speed - 500) * 2 *
- tape->nr_pending_stages / tape->max_stages;
-
- if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
- tape->max_insert_speed = 5000;
- } else
- tape->max_insert_speed = tape->speed_control;
-
- tape->max_insert_speed = max(tape->max_insert_speed, 500);
-}
-
static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
@@ -1548,7 +1455,6 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ /
(jiffies - tape->insert_time);
- idetape_calculate_speeds(drive);
if (!test_and_clear_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags) &&
(stat & SEEK_STAT) == 0) {
if (postponed_rq == NULL) {
@@ -1572,7 +1478,6 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
return ide_stopped;
}
if (rq->cmd[0] & REQ_IDETAPE_READ) {
- tape->buffer_head++;
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_read_cmd(tape, pc, rq->current_nr_sectors,
@@ -1580,7 +1485,6 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
- tape->buffer_head++;
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_write_cmd(tape, pc, rq->current_nr_sectors,
@@ -2312,24 +2216,6 @@ static void idetape_empty_write_pipeline(ide_drive_t *drive)
}
}
-static void idetape_restart_speed_control(ide_drive_t *drive)
-{
- idetape_tape_t *tape = drive->driver_data;
-
- tape->restart_speed_control_req = 0;
- tape->pipeline_head = 0;
- tape->controlled_last_pipeline_head = 0;
- tape->controlled_previous_pipeline_head = 0;
- tape->uncontrolled_previous_pipeline_head = 0;
- tape->controlled_pipeline_head_speed = 5000;
- tape->pipeline_head_speed = 5000;
- tape->uncontrolled_pipeline_head_speed = 0;
- tape->controlled_pipeline_head_time =
- tape->uncontrolled_pipeline_head_time = jiffies;
- tape->controlled_previous_head_time =
- tape->uncontrolled_previous_head_time = jiffies;
-}
-
static int idetape_init_read(ide_drive_t *drive, int max_stages)
{
idetape_tape_t *tape = drive->driver_data;
@@ -2372,8 +2258,6 @@ static int idetape_init_read(ide_drive_t *drive, int max_stages)
}
}
}
- if (tape->restart_speed_control_req)
- idetape_restart_speed_control(drive);
idetape_init_rq(&rq, REQ_IDETAPE_READ);
rq.sector = tape->first_frame;
rq.nr_sectors = blocks;
@@ -2442,8 +2326,6 @@ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
spin_lock_irqsave(&tape->lock, flags);
idetape_remove_stage_head(drive);
spin_unlock_irqrestore(&tape->lock, flags);
- tape->pipeline_head++;
- idetape_calculate_speeds(drive);
}
if (bytes_read > blocks * tape->blk_size) {
printk(KERN_ERR "ide-tape: bug: trying to return more bytes"
@@ -2778,8 +2660,6 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
}
if (count == 0)
return (0);
- if (tape->restart_speed_control_req)
- idetape_restart_speed_control(drive);
if (tape->merge_stage_size) {
if (tape->merge_stage_size >= tape->stage_size) {
printk(KERN_ERR "ide-tape: bug: merge buf too big\n");
@@ -2988,7 +2868,6 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
- tape->restart_speed_control_req = 1;
if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
idetape_empty_write_pipeline(drive);
idetape_flush_tape_buffers(drive);
@@ -3131,8 +3010,6 @@ static int idetape_chrdev_open(struct inode *inode, struct file *filp)
}
}
}
- idetape_restart_speed_control(drive);
- tape->restart_speed_control_req = 0;
return 0;
out_put_tape:
@@ -3335,12 +3212,6 @@ static void idetape_add_settings(ide_drive_t *drive)
NULL);
ide_add_setting(drive, "dsc_overlap", SETTING_RW, TYPE_BYTE, 0, 1, 1,
1, &drive->dsc_overlap, NULL);
- ide_add_setting(drive, "pipeline_head_speed_c", SETTING_READ, TYPE_INT,
- 0, 0xffff, 1, 1, &tape->controlled_pipeline_head_speed,
- NULL);
- ide_add_setting(drive, "pipeline_head_speed_u", SETTING_READ, TYPE_INT,
- 0, 0xffff, 1, 1,
- &tape->uncontrolled_pipeline_head_speed, NULL);
ide_add_setting(drive, "avg_speed", SETTING_READ, TYPE_INT, 0, 0xffff,
1, 1, &tape->avg_speed, NULL);
ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1,
@@ -3386,8 +3257,6 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
tape->name[2] = '0' + minor;
tape->chrdev_dir = IDETAPE_DIR_NONE;
tape->pc = tape->pc_stack;
- tape->max_insert_speed = 10000;
- tape->speed_control = 1;
*((unsigned short *) &gcw) = drive->id->config;
/* Command packet DRQ type */
--
1.5.4.1
--
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