From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: "Michael L. Semon" <mlsemon35@gmail.com>
Cc: linux-kernel@vger.kernel.org,
"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: Re: Slow dc3dd in 3.18 on x86
Date: Fri, 24 Oct 2014 15:54:08 -0400 [thread overview]
Message-ID: <yq1r3xxtfa7.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <544AA317.8070609@gmail.com> (Michael L. Semon's message of "Fri, 24 Oct 2014 15:05:59 -0400")
>>>>> "Michael" == Michael L Semon <mlsemon35@gmail.com> writes:
Michael> This week, a simple `dc3dd wipe=/dev/sda5` operation had speeds
Michael> cut from 10-15 MB/s down to less than 1.8 MB/s. With this
Michael> method, syncs took so long that magic SysRq keys were needed to
Michael> stop the PC. A bisect let me here:
That commit itself doesn't do anything.
I was concerned that somehow integrity got enabled by accident and you
were bogged down by checksum calculations but I see no evidence that
this would be happening. Ran a few tests on ATA systems here.
So I'm puzzled.
Please let me know if the disk has an integrity profile in sysfs.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2014-10-24 19:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-24 19:05 Slow dc3dd in 3.18 on x86 Michael L. Semon
2014-10-24 19:12 ` Martin K. Petersen
2014-10-24 19:54 ` Martin K. Petersen [this message]
2014-10-25 0:29 ` Michael L. Semon
2014-10-25 1:51 ` Martin K. Petersen
2014-10-25 6:37 ` Michael L. Semon
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