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authorBenjamin LaHaise <bcrl@kvack.org>2006-01-08 01:04:34 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-08 20:14:03 -0800
commit59d9136b9844d3a0376d93c945ab280decedb323 (patch)
tree6c3eaa9f902ae983b96500a8d60720610da539a4
parentfb1697933a03ec47d794b38e2a4e3ccc2463fd22 (diff)
[PATCH] aio: reorder kiocb structure elements to make sync iocb setup faster
Reorder members of the kiocb structure to make sync kiocb setup faster. By setting the elements sequentially, the write combining buffers on the CPU are able to combine the writes into a single burst, which results in fewer cache cycles being consumed, freeing them up for other code. This results in a 10-20KB/s[*] increase on the bw_unix part of LMbench on my test system. * The improvement varies based on what other patches are in the system, as there are a number of bottlenecks, so this number is not absolutely accurate. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/linux/aio.h12
1 files changed, 7 insertions, 5 deletions
diff --git a/include/linux/aio.h b/include/linux/aio.h
index 49fd37629ee..00c8efa95cc 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -94,26 +94,27 @@ struct kiocb {
ssize_t (*ki_retry)(struct kiocb *);
void (*ki_dtor)(struct kiocb *);
- struct list_head ki_list; /* the aio core uses this
- * for cancellation */
-
union {
void __user *user;
struct task_struct *tsk;
} ki_obj;
+
__u64 ki_user_data; /* user's data for completion */
+ wait_queue_t ki_wait;
loff_t ki_pos;
+
+ void *private;
/* State that we remember to be able to restart/retry */
unsigned short ki_opcode;
size_t ki_nbytes; /* copy of iocb->aio_nbytes */
char __user *ki_buf; /* remaining iocb->aio_buf */
size_t ki_left; /* remaining bytes */
- wait_queue_t ki_wait;
long ki_retried; /* just for testing */
long ki_kicked; /* just for testing */
long ki_queued; /* just for testing */
- void *private;
+ struct list_head ki_list; /* the aio core uses this
+ * for cancellation */
};
#define is_sync_kiocb(iocb) ((iocb)->ki_key == KIOCB_SYNC_KEY)
@@ -126,6 +127,7 @@ struct kiocb {
(x)->ki_filp = (filp); \
(x)->ki_ctx = NULL; \
(x)->ki_cancel = NULL; \
+ (x)->ki_retry = NULL; \
(x)->ki_dtor = NULL; \
(x)->ki_obj.tsk = tsk; \
(x)->ki_user_data = 0; \