From d01dbc3b85d57f3ab89be4291d4739152bb1713a Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Sun, 27 Apr 2008 15:38:33 +0200 Subject: [PATCH] ide-tape: improve buffer pages freeing strategy Instead of freeing pages one by one, free them 2^order-wise. Also, mv __idetape_kfree_stage() to ide_tape_kfree_buffer(). [bart: add updating bh->b_data] Signed-off-by: Borislav Petkov Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/ide/ide-tape.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c index ea46ed8d044..4e93a82f57e 100644 --- a/drivers/ide/ide-tape.c +++ b/drivers/ide/ide-tape.c @@ -583,20 +583,22 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense) } } -/* Free a stage along with its related buffers completely. */ -static void __idetape_kfree_stage(idetape_stage_t *stage) +/* Free data buffers completely. */ +static void ide_tape_kfree_buffer(idetape_stage_t *stage) { struct idetape_bh *prev_bh, *bh = stage->bh; - int size; - - while (bh != NULL) { - if (bh->b_data != NULL) { - size = (int) bh->b_size; - while (size > 0) { - free_page((unsigned long) bh->b_data); - size -= PAGE_SIZE; - bh->b_data += PAGE_SIZE; - } + + while (bh) { + u32 size = bh->b_size; + + while (size) { + unsigned int order = fls(size >> PAGE_SHIFT)-1; + + if (bh->b_data) + free_pages((unsigned long)bh->b_data, order); + + size &= (order-1); + bh->b_data += (1 << order) * PAGE_SIZE; } prev_bh = bh; bh = bh->b_reqnext; @@ -1373,7 +1375,7 @@ static idetape_stage_t *ide_tape_kmalloc_buffer(idetape_tape_t *tape, int full, atomic_sub(tape->excess_bh_size, &bh->b_count); return stage; abort: - __idetape_kfree_stage(stage); + ide_tape_kfree_buffer(stage); return NULL; } @@ -1649,7 +1651,7 @@ static int __idetape_discard_read_pipeline(ide_drive_t *drive) clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags); tape->merge_stage_size = 0; if (tape->merge_stage != NULL) { - __idetape_kfree_stage(tape->merge_stage); + ide_tape_kfree_buffer(tape->merge_stage); tape->merge_stage = NULL; } @@ -1828,7 +1830,7 @@ static void idetape_empty_write_pipeline(ide_drive_t *drive) tape->merge_stage_size = 0; } if (tape->merge_stage != NULL) { - __idetape_kfree_stage(tape->merge_stage); + ide_tape_kfree_buffer(tape->merge_stage); tape->merge_stage = NULL; } tape->chrdev_dir = IDETAPE_DIR_NONE; @@ -1866,7 +1868,7 @@ static int idetape_init_read(ide_drive_t *drive) REQ_IDETAPE_READ, 0, tape->merge_stage->bh); if (bytes_read < 0) { - __idetape_kfree_stage(tape->merge_stage); + ide_tape_kfree_buffer(tape->merge_stage); tape->merge_stage = NULL; tape->chrdev_dir = IDETAPE_DIR_NONE; return bytes_read; @@ -2145,7 +2147,7 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh); if (retval < 0) { - __idetape_kfree_stage(tape->merge_stage); + ide_tape_kfree_buffer(tape->merge_stage); tape->merge_stage = NULL; tape->chrdev_dir = IDETAPE_DIR_NONE; return retval; @@ -2512,7 +2514,7 @@ static void idetape_write_release(ide_drive_t *drive, unsigned int minor) if (tape->merge_stage != NULL) { idetape_pad_zeros(drive, tape->blk_size * (tape->user_bs_factor - 1)); - __idetape_kfree_stage(tape->merge_stage); + ide_tape_kfree_buffer(tape->merge_stage); tape->merge_stage = NULL; } idetape_write_filemark(drive); -- 2.41.0