From: Ming Lei <ming.lei@redhat.com>
To: Andrea Vai <andrea.vai@unipv.it>
Cc: Damien Le Moal <Damien.LeMoal@wdc.com>,
Alan Stern <stern@rowland.harvard.edu>,
Jens Axboe <axboe@kernel.dk>,
Johannes Thumshirn <jthumshirn@suse.de>,
USB list <linux-usb@vger.kernel.org>,
SCSI development list <linux-scsi@vger.kernel.org>,
Himanshu Madhani <himanshu.madhani@cavium.com>,
Hannes Reinecke <hare@suse.com>, Omar Sandoval <osandov@fb.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Greg KH <gregkh@linuxfoundation.org>,
Hans Holmberg <Hans.Holmberg@wdc.com>,
Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: Slow I/O on USB media after commit f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6
Date: Mon, 25 Nov 2019 11:54:37 +0800 [thread overview]
Message-ID: <20191125035437.GA3806@ming.t460p> (raw)
In-Reply-To: <a9ffcca93657cbbb56819fd883c474a702423b41.camel@unipv.it>
[-- Attachment #1: Type: text/plain, Size: 400 bytes --]
On Sat, Nov 23, 2019 at 04:44:55PM +0100, Andrea Vai wrote:
> Il giorno sab, 23/11/2019 alle 15.28 +0800, Ming Lei ha scritto:
> >
> > Please post the log of 'lsusb -v', and I will try to make a patch
> > for
> > addressing the issue.
>
> attached,
Please apply the attached patch, and re-build & install & reboot kernel.
This time, please don't switch io scheduler.
Thanks,
Ming
[-- Attachment #2: usb.patch --]
[-- Type: text/plain, Size: 3616 bytes --]
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5c9adcaa27ac..eecb46020bfb 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1436,7 +1436,13 @@ static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async,
if (unlikely(blk_mq_hctx_stopped(hctx)))
return;
- if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
+ /*
+ * Some single-queue devices may need to dispatch IO in order
+ * which was guaranteed for the legacy queue via the big queue
+ * lock. Now we reply on single hctx->run_work for that.
+ */
+ if (!async && !(hctx->flags & (BLK_MQ_F_BLOCKING |
+ BLK_MQ_F_STRICT_DISPATCH_ORDER))) {
int cpu = get_cpu();
if (cpumask_test_cpu(cpu, hctx->cpumask)) {
__blk_mq_run_hw_queue(hctx);
@@ -3042,6 +3048,10 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
if (!set->ops->get_budget ^ !set->ops->put_budget)
return -EINVAL;
+ if (set->queue_depth > 1 && (set->flags &
+ BLK_MQ_F_STRICT_DISPATCH_ORDER))
+ return -EINVAL;
+
if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
pr_info("blk-mq: reduced tag depth to %u\n",
BLK_MQ_MAX_DEPTH);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d3d237a09a78..563188844143 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1939,6 +1939,9 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost)
shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
shost->tag_set.flags |=
BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
+ if (shost->hostt->strict_dispatch_order)
+ shost->tag_set.flags |= BLK_MQ_F_STRICT_DISPATCH_ORDER;
+
shost->tag_set.driver_data = shost;
return blk_mq_alloc_tag_set(&shost->tag_set);
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 6737fab94959..77795edad8e8 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -661,6 +661,18 @@ static const struct scsi_host_template usb_stor_host_template = {
/* we do our own delay after a device or bus reset */
.skip_settle_delay = 1,
+
+ /*
+ * Some USB storage, such as Kingston Technology DataTraveler 100
+ * G3/G4/SE9 G2(ID 0951:1666), requires IO dispatched in the
+ * sequential order, otherwise IO performance may drop drastically.
+ *
+ * can_queue is always 1, so we set .strict_dispatch_order for
+ * USB mass storage HBA. Another reason is that there can be such
+ * kind of devices too.
+ */
+ .strict_dispatch_order = 1,
+
/* sysfs device attributes */
.sdev_attrs = sysfs_device_attr_list,
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index dc03e059fdff..844539690a27 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -388,6 +388,7 @@ struct blk_mq_ops {
enum {
BLK_MQ_F_SHOULD_MERGE = 1 << 0,
BLK_MQ_F_TAG_SHARED = 1 << 1,
+ BLK_MQ_F_STRICT_DISPATCH_ORDER = 1 << 2,
BLK_MQ_F_BLOCKING = 1 << 5,
BLK_MQ_F_NO_SCHED = 1 << 6,
BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index d4452d0ea3c7..f932d6fa1a4c 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -442,6 +442,13 @@ struct scsi_host_template {
/* True if the low-level driver supports blk-mq only */
unsigned force_blk_mq:1;
+ /*
+ * True if the low-level driver needs IO to be dispatched in
+ * the order provided by legacy IO path. The flag is only
+ * valid for single queue device.
+ */
+ unsigned strict_dispatch_order:1;
+
/*
* Countdown for host blocking with no commands outstanding.
*/
next prev parent reply other threads:[~2019-11-25 3:55 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <307581a490b610c3025ee80f79a465a89d68ed19.camel@unipv.it>
2019-08-20 17:13 ` Slow I/O on USB media after commit f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6 Alan Stern
2019-08-23 10:39 ` Andrea Vai
2019-08-23 20:42 ` Alan Stern
2019-08-26 6:09 ` Andrea Vai
2019-08-26 16:33 ` Alan Stern
2019-09-18 15:25 ` Andrea Vai
2019-09-18 16:30 ` Alan Stern
2019-09-19 7:33 ` Andrea Vai
2019-09-19 17:54 ` Alan Stern
2019-09-20 7:25 ` Andrea Vai
2019-09-20 7:44 ` Greg KH
2019-09-19 8:26 ` Damien Le Moal
2019-09-19 8:55 ` Ming Lei
2019-09-19 9:09 ` Damien Le Moal
2019-09-19 9:21 ` Ming Lei
2019-09-19 14:01 ` Alan Stern
2019-09-19 14:14 ` Damien Le Moal
2019-09-20 7:03 ` Andrea Vai
2019-09-25 19:30 ` Alan Stern
2019-09-25 19:36 ` Jens Axboe
2019-09-27 15:47 ` Andrea Vai
2019-11-04 16:00 ` Andrea Vai
2019-11-04 18:20 ` Alan Stern
2019-11-05 11:48 ` Andrea Vai
2019-11-05 18:31 ` Alan Stern
2019-11-05 23:29 ` Jens Axboe
2019-11-06 16:03 ` Alan Stern
2019-11-06 22:13 ` Damien Le Moal
2019-11-07 7:04 ` Andrea Vai
2019-11-07 7:54 ` Damien Le Moal
2019-11-07 18:59 ` Andrea Vai
2019-11-08 8:42 ` Damien Le Moal
2019-11-08 14:33 ` Jens Axboe
2019-11-11 10:46 ` Andrea Vai
2019-11-09 10:09 ` Ming Lei
2019-11-09 22:28 ` Ming Lei
2019-11-11 10:50 ` Andrea Vai
2019-11-11 11:05 ` Ming Lei
2019-11-11 11:13 ` Andrea Vai
2019-11-22 19:16 ` Andrea Vai
2019-11-23 7:28 ` Ming Lei
2019-11-23 15:44 ` Andrea Vai
2019-11-25 3:54 ` Ming Lei [this message]
2019-11-25 10:11 ` Andrea Vai
2019-11-25 10:29 ` Ming Lei
2019-11-25 14:58 ` Andrea Vai
2019-11-25 15:15 ` Ming Lei
2019-11-25 18:51 ` Andrea Vai
2019-11-26 2:32 ` Ming Lei
2019-11-26 7:46 ` Andrea Vai
2019-11-26 9:15 ` Ming Lei
2019-11-26 10:24 ` Ming Lei
2019-11-26 11:14 ` Andrea Vai
2019-11-27 2:05 ` Ming Lei
2019-11-27 9:39 ` Andrea Vai
2019-11-27 13:08 ` Ming Lei
2019-11-27 15:01 ` Andrea Vai
2019-11-27 0:21 ` Finn Thain
2019-11-27 8:14 ` AW: " Schmid, Carsten
2019-11-27 21:49 ` Finn Thain
2019-11-28 7:46 ` Andrea Vai
2019-11-28 8:12 ` AW: " Schmid, Carsten
2019-11-28 11:40 ` Andrea Vai
2019-11-28 17:39 ` Alan Stern
2019-11-28 9:17 ` Ming Lei
2019-11-28 17:34 ` Andrea Vai
2019-11-29 0:57 ` Ming Lei
2019-11-29 2:35 ` Ming Lei
2019-11-29 14:41 ` Andrea Vai
2019-12-03 2:23 ` Ming Lei
2019-12-10 7:35 ` Andrea Vai
2019-12-10 8:05 ` Ming Lei
2019-12-11 2:41 ` Theodore Y. Ts'o
2019-12-11 4:00 ` Ming Lei
2019-12-11 16:07 ` Theodore Y. Ts'o
2019-12-11 21:33 ` Ming Lei
2019-12-12 7:34 ` Andrea Vai
2019-12-18 8:25 ` Andrea Vai
2019-12-18 9:48 ` Ming Lei
[not found] ` <b1b6a0e9d690ecd9432025acd2db4ac09f834040.camel@unipv.it>
2019-12-23 13:08 ` Ming Lei
2019-12-23 14:02 ` Andrea Vai
2019-12-24 1:32 ` Ming Lei
2019-12-24 8:04 ` Andrea Vai
2019-12-24 8:47 ` Ming Lei
2019-12-23 16:26 ` Theodore Y. Ts'o
2019-12-23 16:29 ` Andrea Vai
2019-12-23 17:22 ` Theodore Y. Ts'o
2019-12-23 18:45 ` Andrea Vai
2019-12-23 19:53 ` Theodore Y. Ts'o
2019-12-24 1:27 ` Ming Lei
2019-12-24 6:49 ` Andrea Vai
2019-12-24 8:51 ` Andrea Vai
2019-12-24 9:35 ` Ming Lei
2019-12-25 5:17 ` Theodore Y. Ts'o
2019-12-26 2:27 ` Ming Lei
2019-12-26 3:30 ` Theodore Y. Ts'o
2019-12-26 8:37 ` Ming Lei
2020-01-07 7:51 ` Andrea Vai
[not found] ` <20200101074310.10904-1-hdanton@sina.com>
2020-01-01 13:53 ` slow IO on USB media Ming Lei
2019-11-29 11:44 ` AW: Slow I/O on USB media after commit f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6 Bernd Schubert
2019-12-02 7:01 ` Andrea Vai
2019-11-28 17:10 ` Andrea Vai
[not found] <e3f87757f7a0fdf551e911ad32fc8122eebe04c7.camel@unipv.it>
2019-08-13 19:52 ` Alan Stern
2019-07-02 10:46 Andrea Vai
2019-07-02 11:51 ` Johannes Thumshirn
2019-07-02 22:36 ` Andrea Vai
2019-07-03 7:29 ` Johannes Thumshirn
2019-07-03 14:23 ` Alan Stern
2019-07-06 22:06 ` Andrea Vai
2019-07-08 15:38 ` Alan Stern
2019-07-02 12:01 ` Ming Lei
2019-07-02 22:39 ` Andrea Vai
2019-07-03 2:01 ` Ming Lei
2019-07-03 5:11 ` Andrea Vai
2019-07-03 6:36 ` Ming Lei
2019-07-03 15:27 ` Chris Murphy
2019-07-06 9:33 ` Andrea Vai
2019-07-08 1:01 ` Ming Lei
2019-07-09 21:18 ` Andrea Vai
2019-07-10 2:44 ` Ming Lei
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