Linux-USB Archive on lore.kernel.org
 help / color / Atom feed
From: Andrea Vai <andrea.vai@unipv.it>
To: Jens Axboe <axboe@kernel.dk>, Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
	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>, Ming Lei <ming.lei@redhat.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, 11 Nov 2019 11:46:12 +0100
Message-ID: <83c6176bf08d52bf71a4635d62a1c2c4ad97a88d.camel@unipv.it> (raw)
In-Reply-To: <72fc7fd1-cf86-969c-d1ed-36201cf9510a@kernel.dk>

Il giorno ven, 08/11/2019 alle 07.33 -0700, Jens Axboe ha scritto:
> On 11/8/19 1:42 AM, Damien Le Moal wrote:
> > On 2019/11/08 4:00, Andrea Vai wrote:
> >> [Sorry for the duplicate message, it didn't reach the lists due
> to
> >> html formatting]
> >> Il giorno gio 7 nov 2019 alle ore 08:54 Damien Le Moal
> >> <Damien.LeMoal@wdc.com> ha scritto:
> >>>
> >>> On 2019/11/07 16:04, Andrea Vai wrote:
> >>>> Il giorno mer, 06/11/2019 alle 22.13 +0000, Damien Le Moal ha
> scritto:
> >>>>>
> >>>>>
> >>>>> Please simply try your write tests after doing this:
> >>>>>
> >>>>> echo mq-deadline > /sys/block/<name of your USB
> >>>>> disk>/queue/scheduler
> >>>>>
> >>>>> And confirm that mq-deadline is selected with:
> >>>>>
> >>>>> cat /sys/block/<name of your USB disk>/queue/scheduler
> >>>>> [mq-deadline] kyber bfq none
> >>>>
> >>>> ok, which kernel should I test with this: the fresh git cloned,
> or the
> >>>> one just patched with Alan's patch, or doesn't matter which
> one?
> >>>
> >>> Probably all of them to see if there are any differences.
> >>
> >> with both kernels, the output of
> >> cat /sys/block/sdh/queue/schedule
> >>
> >> already contains [mq-deadline]: is it correct to assume that the
> echo
> >> command and the subsequent testing is useless? What to do now?
> > 
> > Probably, yes. Have you obtained a blktrace of the workload during
> these
> > tests ? Any significant difference in the IO pattern (IO size and
> > randomness) and IO timing (any device idle time where the device
> has no
> > command to process) ? Asking because the problem may be above the
> block
> > layer, with the file system for instance.
> 
> blktrace would indeed be super useful, especially if you can do that
> with a kernel that's fast for you, and one with the current kernel
> where it's slow.
> 
> Given that your device is sdh, you simply do:
> 
> # blktrace /dev/sdh
> 
> and then run the test, then ctrl-c the blktrace. Then do:
> 
> # blkparse sdh > output
> 
> and save that output file. Do both runs, and bzip2 them up. The
> shorter
> the run you can reproduce with the better, to cut down on the size
> of
> the traces.

Sorry, the next message from Ming...

-----
You may get the IO pattern via the previous trace 
https://lore.kernel.org/linux-usb/20190710024439.GA2621@ming.t460p/

IMO, if it is related write order, one possibility could be that
the queue lock is killed in .make_request_fn().
-----

...made me wonder if I should really do the blkparse trace test, or
not. So please confirm if it's needed (testing is quite time-consuming 
, so I'd like to do it if it's needed).

Thanks, and bye,
Andrea


  reply index

Thread overview: 91+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <307581a490b610c3025ee80f79a465a89d68ed19.camel@unipv.it>
2019-08-20 17:13 ` 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 [this message]
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
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
2019-11-29 11:44                                                                                     ` 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

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=83c6176bf08d52bf71a4635d62a1c2c4ad97a88d.camel@unipv.it \
    --to=andrea.vai@unipv.it \
    --cc=Damien.LeMoal@wdc.com \
    --cc=Hans.Holmberg@wdc.com \
    --cc=axboe@kernel.dk \
    --cc=gregkh@linuxfoundation.org \
    --cc=hare@suse.com \
    --cc=himanshu.madhani@cavium.com \
    --cc=jthumshirn@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=ming.lei@redhat.com \
    --cc=osandov@fb.com \
    --cc=stern@rowland.harvard.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-USB Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-usb/0 linux-usb/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-usb linux-usb/ https://lore.kernel.org/linux-usb \
		linux-usb@vger.kernel.org
	public-inbox-index linux-usb

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-usb


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git