Date: Sat, 20 Feb 1999 16:30:58 -0700 From: Allen Campbell <allenc@verinet.com> To: "Kenneth D. Merry" <ken@plutotech.com> Cc: stable@FreeBSD.ORG Subject: Re: Tagged queueing Message-ID: <36CF45B2.14AE3598@verinet.com> References: <199902201930.MAA13801@panzer.plutotech.com>
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"Kenneth D. Merry" wrote:
>
> Ruslan Ermilov wrote...
> > Hi!
> >
> > When my system was running 2.2.8-STABLE,
> > I had AHC_TAGENABLE in the kernel, and it
> > worked fine, at least dmesg reported that.
> >
> > Now, on a 3.1-STABLE (today's freshness)
> > it doesn't.
> >
> > `dmesg' output and kernel config are attached.
> >
> > Any clue on what has happened?
>
> The AHC_TAGENABLE option is no longer necessary. Tagged queueing is
> enabled by default.
>
> The reason your drive does not have tagged queueing enabled is because it is
> a Western Digital Enterprise drive:
>
> da0 at ahc0 bus 0 target 0 lun 0
> da0: <WDIGTL ENTERPRISE 1.80> Fixed Direct Access SCSI-2 device
> da0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit)
> da0: 4157MB (8515173 512 byte sectors: 64H 32S/T 4157C)
>
> Andrew Gallatin reported that his western digital enterprise drives only
> get 1.5MB/sec throughput with tagged queueing turned on, and 8MB/sec
> throughput with tagged queueing turned off. Therefore, we have a quirk
> entry in the transport layer that disables tagged queueing for those
> drives.
>
> Next time, if you have the cash, get an IBM or Seagate disk. They
> generally write much better disk firmware.
>
> Ken
> --
> Kenneth Merry
> ken@plutotech.com
1.5MB/sec with tagged queuing (not queueing) turned on? Hmmm...
The following is from an Asus P97S with a P2/233:
uname -rm:
2.2.7-STABLE i386
(no CAM, btw)
Bit of dmesg (with AHC_TAGENABLE):
ahc0: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
ahc0: Resetting Channel A
ahc0: Downloading Sequencer Program...ahc0: 374 instructions downloaded
Done
ahc0: Probing channel A
ahc0 waiting for scsi devices to settle
ahc0: target 0 using 16Bit transfers
ahc0: target 0 synchronous at 20.0MHz, offset = 0x8
ahc0: target 0 Tagged Queuing Device
(ahc0:0:0): "WDIGTL ENTERPRISE 1.91" type 0 fixed SCSI 2
sd0(ahc0:0:0): Direct-Access 4157MB (8515173 512 byte sectors)
sd0(ahc0:0:0): with 5720 cyls, 8 heads, and an average 186 sectors/track
ahc0: target 1 synchronous at 20.0MHz, offset = 0xf
bonnie results with and without AHC_TAGENABLE:
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
TAG-Q-ON 100 4936 37.6 4548 8.4 2274 6.2 8288 66.1 7973 13.2 140.8 2.9
TAG-Q-OFF 100 3986 30.5 3986 7.1 2410 5.3 8091 64.3 8001 9.2 125.7 2.1
About the only loser with AHC_TAGENABLE is Block Sequential Input.
To be honest, that makes me wonder more about the SCSI driver than
the drive firmware.
How was this 1.5MB/sec measured? I'd like to duplicate the test.
Ruslan's drive reported 'WDIGTL ENTERPRISE 1.80', as opposed to
the 1.91 from my dmesg output. Perhaps the newer firmware has
something to do with this.
Sorry for the long lines. I didn't wrap parts of this to keep
the bonnie output straight.
--
Allen Campbell | Lurking at the bottom of the
allenc@verinet.com | gravity well, getting old.
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