From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Ming Lei <tom.leiming@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Eryu Guan <guaneryu@gmail.com>,
Linux SCSI List <linux-scsi@vger.kernel.org>
Subject: Re: kernel BUG at block/bio.c:1787! while initializing scsi_debug on ppc64 host
Date: Tue, 15 Dec 2015 20:37:14 -0500 [thread overview]
Message-ID: <yq1si33uqb9.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <CACVXFVPEK4TM9XtY-WGs=9--3NvxpsO8au+L2ex5xKKpHpdM-g@mail.gmail.com> (Ming Lei's message of "Wed, 16 Dec 2015 09:17:43 +0800")
>>>>> "Ming" == Ming Lei <tom.leiming@gmail.com> writes:
Ming,
Ming> No, it can't.
Well, it fixes a problem on one of my test systems where max_ws_blocks,
by virtue of being 64 bits, clobbers opt_xfer_blocks causing rw_len and
thus max_sectors to be set incorrectly.
We haven't run into that issue on real hardware. Probably because
scsi_debug is the only driver reporting $LUDICROUS_NUMBER as the max hw
transfer.
Ming> As the debug log shows, it is because you use 'OPTIMAL TRANSFER
Ming> LENGTH' to set queue's max_sectors.
But that is intentional.
I agree that the value chosen by scsi_debug in this case is very low and
we should fix that.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2015-12-16 1:37 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-11 12:01 kernel BUG at block/bio.c:1787! while initializing scsi_debug on ppc64 host Eryu Guan
2015-12-15 11:20 ` Eryu Guan
2015-12-15 12:06 ` Ming Lei
2015-12-15 13:06 ` Eryu Guan
2015-12-15 13:27 ` Ming Lei
2015-12-15 16:56 ` Eryu Guan
2015-12-16 1:15 ` Ming Lei
2015-12-16 1:39 ` Martin K. Petersen
2015-12-15 15:38 ` Ming Lei
2015-12-15 17:16 ` Eryu Guan
2015-12-15 18:29 ` Martin K. Petersen
2015-12-16 1:17 ` Ming Lei
2015-12-16 1:37 ` Martin K. Petersen [this message]
2015-12-16 7:25 ` Eryu Guan
2015-12-15 15:38 ` Martin K. Petersen
2016-01-05 11:57 ` Eryu Guan
2016-01-05 23:58 ` Martin K. Petersen
2016-01-06 3:33 ` Eryu Guan
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