remove some abuse of bufqs where they were overloaded to store workq_tasks

for completing swap io against files. this in turn bloated struct buf.

this moves from using workq_tasks to the task api, but stores the task
handler in vndbuf which is allocated specially for every io in this path
anyway.

ok kettenis@ beck@

2 files changed, 12 insertions, 23 deletions

diff --git a/sys/sys/buf.h b/sys/sys/buf.h
index b2b27ad0c61..8bef4c7195a 100644
--- a/sys/sys/buf.h
+++ b/sys/sys/buf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: buf.h,v 1.89 2013/07/09 15:37:43 beck Exp $	*/
+/*	$OpenBSD: buf.h,v 1.90 2013/11/06 07:46:31 dlg Exp $	*/
 /*	$NetBSD: buf.h,v 1.25 1997/04/09 21:12:17 mycroft Exp $	*/
 
 /*
@@ -42,7 +42,6 @@
 #include <sys/queue.h>
 #include <sys/tree.h>
 #include <sys/mutex.h>
-#include <sys/workq.h>
 
 #define NOLIST ((struct buf *)0x87654321)
 
@@ -126,19 +125,11 @@ struct bufq_nscan {
 	SIMPLEQ_ENTRY(buf)	bqf_entries;
 };
 
-/* Abuse bufq_fifo, for swapping to regular files. */
-struct bufq_swapreg {
-	SIMPLEQ_ENTRY(buf)	bqf_entries;
-	struct workq_task	bqf_wqtask;
-
-};
-
 /* bufq link in struct buf */
 union bufq_data {
 	struct bufq_disksort	bufq_data_disksort;
 	struct bufq_fifo	bufq_data_fifo;
 	struct bufq_nscan	bufq_data_nscan;
-	struct bufq_swapreg	bufq_swapreg;
 };
 
 /*
diff --git a/sys/uvm/uvm_swap.c b/sys/uvm/uvm_swap.c
index 348a0a3623f..24c50edfa77 100644
--- a/sys/uvm/uvm_swap.c
+++ b/sys/uvm/uvm_swap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_swap.c,v 1.120 2013/11/05 06:02:45 deraadt Exp $	*/
+/*	$OpenBSD: uvm_swap.c,v 1.121 2013/11/06 07:46:31 dlg Exp $	*/
 /*	$NetBSD: uvm_swap.c,v 1.40 2000/11/17 11:39:39 mrg Exp $	*/
 
 /*
@@ -50,6 +50,7 @@
 #include <sys/syscallargs.h>
 #include <sys/swap.h>
 #include <sys/disk.h>
+#include <sys/task.h>
 #if defined(NFSCLIENT)
 #include <sys/socket.h>
 #include <sys/domain.h>
@@ -192,7 +193,7 @@ struct vndxfer {
 
 struct vndbuf {
 	struct buf	vb_buf;
-	struct vndxfer	*vb_xfer;
+	struct task	vb_task;
 };
 
 
@@ -1290,7 +1291,8 @@ sw_reg_strategy(struct swapdev *sdp, struct buf *bp, int bn)
 				max(0, bp->b_validend - (bp->b_bcount-resid)));
 		}
 
-		nbp->vb_xfer = vnx;	/* patch it back in to vnx */
+		/* patch it back to the vnx */
+		task_set(&nbp->vb_task, sw_reg_iodone_internal, nbp, vnx);
 
 		/* XXX: In case the underlying bufq is disksort: */
 		nbp->vb_buf.b_cylinder = nbp->vb_buf.b_blkno;
@@ -1365,26 +1367,22 @@ sw_reg_start(struct swapdev *sdp)
  * => note that we can recover the vndbuf struct by casting the buf ptr
  *
  * XXX:
- * We only put this onto a workq here, because of the maxactive game since
+ * We only put this onto a taskq here, because of the maxactive game since
  * it basically requires us to call back into VOP_STRATEGY() (where we must
  * be able to sleep) via sw_reg_start().
  */
 void
 sw_reg_iodone(struct buf *bp)
 {
-	struct bufq_swapreg	*bq;
-
-	bq = (struct bufq_swapreg *)&bp->b_bufq;
-
-	workq_queue_task(NULL, &bq->bqf_wqtask, 0,
-	    (workq_fn)sw_reg_iodone_internal, bp, NULL);
+	struct vndbuf *vbp = (struct vndbuf *)bp;
+	task_add(systq, &vbp->vb_task);
 }
 
 void
-sw_reg_iodone_internal(void *arg0, void *unused)
+sw_reg_iodone_internal(void *xvbp, void *xvnx)
 {
-	struct vndbuf *vbp = (struct vndbuf *)arg0;
-	struct vndxfer *vnx = vbp->vb_xfer;
+	struct vndbuf *vbp = xvbp;
+	struct vndxfer *vnx = xvnx;
 	struct buf *pbp = vnx->vx_bp;		/* parent buffer */
 	struct swapdev	*sdp = vnx->vx_sdp;
 	int resid, s;