From: Finn Thain <fthain@telegraphics.com.au>
To: "Schmid, Carsten" <Carsten_Schmid@mentor.com>
Cc: Andrea Vai <andrea.vai@unipv.it>, Ming Lei <ming.lei@redhat.com>,
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: AW: Slow I/O on USB media after commit f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6
Date: Thu, 28 Nov 2019 08:49:53 +1100 (AEDT) [thread overview]
Message-ID: <alpine.LNX.2.21.1.1911280830520.8@nippy.intranet> (raw)
In-Reply-To: <cb6e84781c4542229a3f31572cef19ab@SVR-IES-MBX-03.mgc.mentorg.com>
On Wed, 27 Nov 2019, Schmid, Carsten wrote:
> >
> > The sheer volume of testing (probably some terabytes by now) would
> > exercise the wear leveling algorithm in the FTL.
> >
> But with "old kernel" the copy operation still is "fast", as far as i
> understood. If FTL (e.g. wear leveling) would slow down, we would see
> that also in the old kernel, right?
>
> Andrea, can you confirm that the same device used with the old fast
> kernel is still fast today?
You seem to be saying we should optimize the kernel for a pathological
use-case merely because it used to be fast before the blk-mq conversion.
That makes no sense to me. I suppose you have information that I don't.
I assume that your employer (and the other corporations involved in this)
have plenty of regression test results from a variety of flash hardware to
show that the regression is real and the device is not pathological.
I'm not privy to any of that information so I will shut up and leave you
guys to it.
--
> > This in itself seems unlikely to improve performance significantly.
> > But if the flash memory came from a bad batch, perhaps it would have
> > that effect.
> >
> > To find out, someone may need to source another (genuine) Kingston
> > DataTraveller device.
> >
next prev parent reply other threads:[~2019-11-27 21:50 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <0cd6ac36b7ab644576fc0f3f5bd4a880c33855d1.camel@unipv.it>
2019-11-05 18:31 ` Slow I/O on USB media after commit f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6 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
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 [this message]
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
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