Module Name: src
Committed By: mlelstv
Date: Fri May 24 06:01:06 UTC 2019
Modified Files:
src/sys/dev/ata: wd.c
Log Message:
Also schedule timeouts when all openings are in use.
To generate a diff of this commit:
cvs rdiff -u -r1.449 -r1.450 src/sys/dev/ata/wd.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/ata/wd.c
diff -u src/sys/dev/ata/wd.c:1.449 src/sys/dev/ata/wd.c:1.450
--- src/sys/dev/ata/wd.c:1.449 Sun Apr 7 13:00:00 2019
+++ src/sys/dev/ata/wd.c Fri May 24 06:01:05 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: wd.c,v 1.449 2019/04/07 13:00:00 bouyer Exp $ */
+/* $NetBSD: wd.c,v 1.450 2019/05/24 06:01:05 mlelstv Exp $ */
/*
* Copyright (c) 1998, 2001 Manuel Bouyer. All rights reserved.
@@ -54,7 +54,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: wd.c,v 1.449 2019/04/07 13:00:00 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: wd.c,v 1.450 2019/05/24 06:01:05 mlelstv Exp $");
#include "opt_ata.h"
#include "opt_wd.h"
@@ -757,6 +757,7 @@ wd_diskstart(device_t dev, struct buf *b
struct ata_xfer *xfer;
struct ata_channel *chp;
unsigned openings;
+ int ticks;
mutex_enter(&wd->sc_lock);
@@ -769,22 +770,37 @@ wd_diskstart(device_t dev, struct buf *b
openings = uimin(openings, wd->drvp->drv_openings);
if (wd->inflight >= openings) {
- mutex_exit(&wd->sc_lock);
- return EAGAIN;
+ /*
+ * pretend we run out of memory when the queue is full,
+ * so that the operation is retried after a minimal
+ * delay.
+ */
+ xfer = NULL;
+ ticks = 1;
+ } else {
+ /*
+ * If there is no available memory, retry later. This
+ * happens very rarely and only under memory pressure,
+ * so wait relatively long before retry.
+ */
+ xfer = ata_get_xfer(chp, false);
+ ticks = hz/2;
}
- xfer = ata_get_xfer(chp, false);
if (xfer == NULL) {
ATADEBUG_PRINT(("wd_diskstart %s no xfer\n",
dksc->sc_xname), DEBUG_XFERS);
/*
- * No available memory, retry later. This happens very rarely
- * and only under memory pressure, so wait relatively long
- * before retry.
+ * The disk queue is pushed automatically when an I/O
+ * operation finishes or another one is queued. We
+ * need this extra timeout because an ATA channel
+ * might be shared by more than one disk queue and
+ * all queues need to be restarted when another slot
+ * becomes available.
*/
if (!callout_pending(&wd->sc_restart_diskqueue)) {
- callout_reset(&wd->sc_restart_diskqueue, hz / 2,
+ callout_reset(&wd->sc_restart_diskqueue, ticks,
wdrestart, dev);
}
