From: Gene Heskett <gene.heskett@verizon.net>
To: linux-kernel@vger.kernel.org
Subject: Re: Disk write cache (Was: Hyper-Threading Vulnerability)
Date: Sun, 15 May 2005 11:21:36 -0400 [thread overview]
Message-ID: <200505151121.36243.gene.heskett@verizon.net> (raw)
In-Reply-To: <Pine.LNX.4.58.0505151657230.19181@artax.karlin.mff.cuni.cz>
On Sunday 15 May 2005 11:00, Mikulas Patocka wrote:
>On Sun, 15 May 2005, Tomasz Torcz wrote:
>> On Sun, May 15, 2005 at 04:12:07PM +0200, Andi Kleen wrote:
>> > > > > However they've patched the FreeBSD kernel to
>> > > > > "workaround?" it:
>> > > > > ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-05:09/ht
>> > > > >t5.patch
>> > > >
>> > > > That's a similar stupid idea as they did with the disk write
>> > > > cache (lowering the MTBFs of their disks by considerable
>> > > > factors, which is much worse than the power off data loss
>> > > > problem) Let's not go down this path please.
>> > >
>> > > What wrong did they do with disk write cache?
>> >
>> > They turned it off by default, which according to disk vendors
>> > lowers the MTBF of your disk to a fraction of the original
>> > value.
>> >
>> > I bet the total amount of valuable data lost for FreeBSD users
>> > because of broken disks is much much bigger than what they
>> > gained from not losing in the rather hard to hit power off
>> > cases.
>>
>> Aren't I/O barriers a way to safely use write cache?
>
>FreeBSD used these barriers (FLUSH CACHE command) long time ago.
>
>There are rumors that some disks ignore FLUSH CACHE command just to
> get higher benchmarks in Windows. But I haven't heart of any proof.
> Does anybody know, what companies fake this command?
>
>From a story I read elsewhere just a few days ago, this problem is
virtually universal even in the umpty-bucks 15,000 rpm scsi server
drives. It appears that this is just another way to crank up the
numbers and make each drive seem faster than its competition.
My gut feeling is that if this gets enough ink to get under the drive
makers skins, we will see the issuance of a utility from the makers
that will re-program the drives therefore enabling the proper
handling of the FLUSH CACHE command. This would be an excellent
chance IMO, to make a bit of noise if the utility comes out, but only
runs on windows. In that event, we hold their feet to the fire (the
prefereable method), or a wrapper is written that allows it to run on
any os with a bash-like shell manager.
>Mikulas
>-
>To unsubscribe from this list: send the line "unsubscribe
> linux-kernel" in the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html
>Please read the FAQ at http://www.tux.org/lkml/
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.34% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2005 by Maurice Eugene Heskett, all rights reserved.
next prev parent reply other threads:[~2005-05-15 15:21 UTC|newest]
Thread overview: 150+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-13 5:51 Hyper-Threading Vulnerability Gabor MICSKO
2005-05-13 12:47 ` Barry K. Nathan
2005-05-13 14:10 ` Jeff Garzik
2005-05-13 14:23 ` Daniel Jacobowitz
2005-05-13 14:32 ` Jeff Garzik
2005-05-13 17:13 ` Andy Isaacson
2005-05-13 18:30 ` Vadim Lobanov
2005-05-13 19:02 ` Andy Isaacson
2005-05-15 9:31 ` Adrian Bunk
2005-05-13 17:14 ` Gabor MICSKO
2005-05-13 20:23 ` Barry K. Nathan
2005-05-13 18:03 ` Andi Kleen
2005-05-13 18:34 ` Eric Rannaud
2005-05-13 18:35 ` Alan Cox
2005-05-13 18:49 ` Scott Robert Ladd
2005-05-13 19:08 ` Andi Kleen
2005-05-13 19:36 ` Grant Coady
2005-05-16 17:00 ` Linus Torvalds
2005-05-16 12:37 ` Tommy Reynolds
2005-05-18 19:07 ` Bill Davidsen
2005-05-13 18:38 ` Richard F. Rebel
2005-05-13 19:05 ` Andi Kleen
2005-05-13 21:26 ` Andy Isaacson
2005-05-13 21:59 ` Matt Mackall
2005-05-13 22:47 ` Alan Cox
2005-05-13 23:00 ` Lee Revell
2005-05-13 23:27 ` Dave Jones
2005-05-13 23:38 ` Lee Revell
2005-05-13 23:44 ` Dave Jones
2005-05-14 7:37 ` Lee Revell
2005-05-14 15:33 ` Andrea Arcangeli
2005-05-15 1:07 ` Christer Weinigel
2005-05-15 9:48 ` Andi Kleen
2005-05-14 15:23 ` Alan Cox
2005-05-14 15:45 ` andrea
2005-05-15 13:38 ` Mikulas Patocka
2005-05-16 7:06 ` andrea
2005-05-14 16:30 ` Lee Revell
2005-05-14 16:44 ` Arjan van de Ven
2005-05-14 17:56 ` Lee Revell
2005-05-14 18:01 ` Arjan van de Ven
2005-05-14 19:21 ` Lee Revell
2005-05-14 19:48 ` Arjan van de Ven
2005-05-14 23:40 ` Lee Revell
2005-05-15 7:30 ` Arjan van de Ven
2005-05-15 20:41 ` Alan Cox
2005-05-15 20:48 ` Arjan van de Ven
2005-05-15 21:10 ` Lee Revell
2005-05-15 22:55 ` Dave Jones
2005-05-15 23:10 ` Lee Revell
2005-05-16 7:25 ` Arjan van de Ven
2005-05-15 9:37 ` Andi Kleen
2005-05-15 3:19 ` dean gaudet
2005-05-15 10:01 ` Andi Kleen
2005-05-15 10:23 ` 2.6.4 timer and helper functions kernel
2005-05-19 0:38 ` George Anzinger
2005-05-15 9:33 ` Hyper-Threading Vulnerability Adrian Bunk
2005-05-14 17:04 ` Jindrich Makovicka
2005-05-14 18:27 ` Lee Revell
2005-05-15 9:58 ` Andi Kleen
2005-05-14 0:39 ` dean gaudet
2005-05-16 13:41 ` Andrea Arcangeli
2005-05-15 9:43 ` Andi Kleen
2005-05-15 18:42 ` David Schwartz
2005-05-15 18:56 ` Dr. David Alan Gilbert
2005-05-16 7:10 ` Eric W. Biederman
2005-05-16 11:04 ` Andi Kleen
2005-05-16 19:14 ` Eric W. Biederman
2005-05-16 20:05 ` Valdis.Kletnieks
2005-05-15 14:00 ` Mikulas Patocka
2005-05-15 14:26 ` Andi Kleen
2005-05-13 23:32 ` Paul Jakma
2005-05-14 16:29 ` Paul Jakma
2005-05-13 19:14 ` Jim Crilly
2005-05-13 20:18 ` Barry K. Nathan
2005-05-13 23:14 ` Jim Crilly
2005-05-13 19:16 ` Diego Calleja
2005-05-13 19:42 ` Frank Denis (Jedi/Sector One)
2005-05-15 9:54 ` Andi Kleen
2005-05-15 13:51 ` Mikulas Patocka
2005-05-15 14:12 ` Andi Kleen
2005-05-15 14:21 ` Mikulas Patocka
2005-05-15 14:52 ` Tomasz Torcz
2005-05-15 15:00 ` Disk write cache (Was: Hyper-Threading Vulnerability) Mikulas Patocka
2005-05-15 15:21 ` Gene Heskett [this message]
2005-05-15 15:29 ` Jeff Garzik
2005-05-15 16:27 ` Disk write cache Kenichi Okuyama
2005-05-15 16:43 ` Jeff Garzik
2005-05-15 16:50 ` Kyle Moffett
2005-05-15 16:56 ` Andi Kleen
2005-05-15 20:44 ` Andrew Morton
2005-05-15 23:31 ` Cache based insecurity/CPU cache/Disk Cache Tradeoffs Brian O'Mahoney
2005-05-15 16:58 ` Disk write cache Mikulas Patocka
2005-05-15 17:20 ` Kenichi Okuyama
2005-05-16 11:02 ` Linux does not care for data integrity (was: Disk write cache) Matthias Andree
2005-05-16 11:12 ` Arjan van de Ven
2005-05-16 11:29 ` Matthias Andree
2005-05-16 14:02 ` Arjan van de Ven
2005-05-16 14:48 ` Matthias Andree
2005-05-16 15:06 ` Alan Cox
2005-05-16 15:40 ` Matthias Andree
2005-05-16 18:04 ` Alan Cox
2005-05-16 19:11 ` Linux does not care for data integrity Florian Weimer
2005-05-29 21:02 ` Linux does not care for data integrity (was: Disk write cache) Greg Stark
2005-05-29 21:16 ` Matthias Andree
2005-05-30 6:04 ` Greg Stark
2005-05-30 8:21 ` Matthias Andree
2005-06-01 19:02 ` Linux does not care for data integrity Bill Davidsen
2005-06-01 22:02 ` Matthias Andree
2005-06-02 0:12 ` Bill Davidsen
2005-06-02 0:36 ` Jeff Garzik
2005-06-02 1:37 ` Bill Davidsen
2005-06-02 1:54 ` Jeff Garzik
2005-06-02 8:53 ` Helge Hafting
2005-06-02 12:00 ` Bill Davidsen
2005-06-02 13:33 ` Lennart Sorensen
2005-06-04 13:37 ` Bill Davidsen
2005-06-04 15:31 ` Bernd Eckenfels
2005-05-16 14:57 ` Linux does not care for data integrity (was: Disk write cache) Alan Cox
2005-05-16 13:48 ` Linux does not care for data integrity Mark Lord
2005-05-16 14:59 ` Matthias Andree
2005-05-16 1:56 ` Disk write cache (Was: Hyper-Threading Vulnerability) Gene Heskett
2005-05-16 2:11 ` Jeff Garzik
2005-05-16 2:24 ` Mikulas Patocka
2005-05-16 3:05 ` Gene Heskett
2005-05-16 2:32 ` Mark Lord
2005-05-16 3:08 ` Gene Heskett
2005-05-16 13:44 ` Mark Lord
2005-05-18 4:03 ` Eric D. Mudama
2005-05-15 16:24 ` Mikulas Patocka
2005-05-16 11:18 ` Matthias Andree
2005-05-16 14:33 ` Jeff Garzik
2005-05-16 15:26 ` Richard B. Johnson
2005-05-16 16:00 ` [OT] drive behavior on power-off (was: Disk write cache) Matthias Andree
2005-05-16 18:11 ` Disk write cache (Was: Hyper-Threading Vulnerability) Valdis.Kletnieks
2005-05-16 14:54 ` Alan Cox
2005-05-17 13:15 ` Bill Davidsen
2005-05-17 21:41 ` Kyle Moffett
2005-05-18 4:06 ` Eric D. Mudama
2005-05-15 21:38 ` Tomasz Torcz
2005-05-16 14:50 ` Alan Cox
2005-05-15 15:00 ` Hyper-Threading Vulnerability Arjan van de Ven
[not found] <43Bnu-Ut-9@gated-at.bofh.it>
[not found] ` <44sLm-3Mg-33@gated-at.bofh.it>
[not found] ` <44sUX-42h-11@gated-at.bofh.it>
[not found] ` <44teb-4fb-1@gated-at.bofh.it>
[not found] ` <44uaj-4Z3-5@gated-at.bofh.it>
[not found] ` <44LXu-2W6-15@gated-at.bofh.it>
[not found] ` <44OVj-5xS-3@gated-at.bofh.it>
[not found] ` <44PRr-6mz-33@gated-at.bofh.it>
2005-05-17 3:29 ` Disk write cache (Was: Hyper-Threading Vulnerability) Robert Hancock
2005-05-18 4:11 ` Eric D. Mudama
2005-05-18 7:16 Paul Zimmerman
2005-05-18 11:10 ` Richard B. Johnson
2005-05-18 12:47 ` Stephan Wonczak
2005-05-18 9:45 Lincoln Dale (ltd)
2005-05-18 13:48 ` John Stoffel
2005-05-18 22:11 Lincoln Dale (ltd)
Reply instructions:
You may reply publicly 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=200505151121.36243.gene.heskett@verizon.net \
--to=gene.heskett@verizon.net \
--cc=linux-kernel@vger.kernel.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).