lkml.org 
[lkml]   [2005]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH Linux 2.6.12-rc2 01/04] blk: use find_first_zero_bit() in blk_queue_start_tag()
Date
01_blk_tag_map_use_find_first_zero_bit.patch

blk_queue_start_tag() hand-coded searching for the first zero
bit in the tag map. Replace it with find_first_zero_bit().
With this patch, blk_queue_star_tag() doesn't need to fill
remains of tag map with 1, thus allowing it to work properly
with the next remove_real_max_depth patch.

Signed-off-by: Tejun Heo <htejun@gmail.com>

ll_rw_blk.c | 13 ++++---------
1 files changed, 4 insertions(+), 9 deletions(-)

Index: blk-fixes/drivers/block/ll_rw_blk.c
===================================================================
--- blk-fixes.orig/drivers/block/ll_rw_blk.c 2005-04-20 20:36:35.000000000 +0900
+++ blk-fixes/drivers/block/ll_rw_blk.c 2005-04-20 20:36:36.000000000 +0900
@@ -967,8 +967,7 @@ EXPORT_SYMBOL(blk_queue_end_tag);
int blk_queue_start_tag(request_queue_t *q, struct request *rq)
{
struct blk_queue_tag *bqt = q->queue_tags;
- unsigned long *map = bqt->tag_map;
- int tag = 0;
+ int tag;

if (unlikely((rq->flags & REQ_QUEUED))) {
printk(KERN_ERR
@@ -977,14 +976,10 @@ int blk_queue_start_tag(request_queue_t
BUG();
}

- for (map = bqt->tag_map; *map == -1UL; map++) {
- tag += BLK_TAGS_PER_LONG;
-
- if (tag >= bqt->max_depth)
- return 1;
- }
+ tag = find_first_zero_bit(bqt->tag_map, bqt->max_depth);
+ if (tag >= bqt->max_depth)
+ return 1;

- tag += ffz(*map);
__set_bit(tag, bqt->tag_map);

rq->flags |= REQ_QUEUED;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-04-20 13:46    [W:0.034 / U:8.556 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site