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authorRichard Kennedy <richard@rsk.demon.co.uk>2010-03-19 08:58:16 +0100
committerJens Axboe <jens.axboe@oracle.com>2010-03-19 08:58:16 +0100
commit181fdde3b4268cb7b4af76ba6337e7ec8accbb36 (patch)
tree6f2e3f177f21f6e299e84bc9075ac1ae257a301c
parentb4b7a4ef097f288f724420b473dbf92a89c0ab7e (diff)
downloadop-kernel-dev-181fdde3b4268cb7b4af76ba6337e7ec8accbb36.zip
op-kernel-dev-181fdde3b4268cb7b4af76ba6337e7ec8accbb36.tar.gz
block: remove 16 bytes of padding from struct request on 64bits
Remove alignment padding to shrink struct request from 336 to 320 bytes so needing one fewer cacheline and therefore removing 48 bytes from struct request_queue. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--include/linux/blkdev.h11
1 files changed, 6 insertions, 5 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 41551c9..6690e8b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -158,7 +158,6 @@ enum rq_flag_bits {
struct request {
struct list_head queuelist;
struct call_single_data csd;
- int cpu;
struct request_queue *q;
@@ -166,9 +165,11 @@ struct request {
enum rq_cmd_type_bits cmd_type;
unsigned long atomic_flags;
+ int cpu;
+
/* the following two fields are internal, NEVER access directly */
- sector_t __sector; /* sector cursor */
unsigned int __data_len; /* total data len */
+ sector_t __sector; /* sector cursor */
struct bio *bio;
struct bio *biotail;
@@ -201,20 +202,20 @@ struct request {
unsigned short ioprio;
+ int ref_count;
+
void *special; /* opaque pointer available for LLD use */
char *buffer; /* kaddr of the current segment if available */
int tag;
int errors;
- int ref_count;
-
/*
* when request is used as a packet command carrier
*/
- unsigned short cmd_len;
unsigned char __cmd[BLK_MAX_CDB];
unsigned char *cmd;
+ unsigned short cmd_len;
unsigned int extra_len; /* length of alignment and padding */
unsigned int sense_len;
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