2000-11-14 01:28:58

by Andries Brouwer

[permalink] [raw]
Subject: Re: IDE0 /dev/hda performance hit in 2217 on my HW - more info - maybe extended partitions

On Mon, Nov 13, 2000 at 03:47:27PM -0800, LA Walsh wrote:

> Some further information in response to a private email, I did hdparm -ti
> under both
> 2216 and 2217 -- they are identical -- this may be something weird
> w/extended partitions...

What nonsense. There is nothing special with extended partitions.
Partitions influence the logical view on the disk, but not I/O.

(But the outer rim of a disk is faster than the inner side.)

Moreover, you report elapsed times
0:27, 0:22, 0:24, 0:28, 0:21, 0:24, 0:27
where is this performance hit?


2000-11-14 07:53:32

by L A Walsh

[permalink] [raw]
Subject: RE: IDE0 /dev/hda performance hit in 2217 on my HW - more info - maybe extended partitions

It seems to be the output of vmstat that isn't matching things. First it
says
it's getting near 10M/s, but if you divide 128M/27 seconds, it's more like
4.7.
So where is the time being wasted? It's not in cpu either.

Now I look at hda7 where vmstat reported 2000-3000 blocks/sec. Again, the
math
says it's a rate near 5m/s. So it still doesn't make sense.



> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Andries Brouwer
> Sent: Monday, November 13, 2000 4:59 PM
> To: LA Walsh
> Cc: lkml
> Subject: Re: IDE0 /dev/hda performance hit in 2217 on my HW - more info
> - maybe extended partitions
>
>
> On Mon, Nov 13, 2000 at 03:47:27PM -0800, LA Walsh wrote:
>
> > Some further information in response to a private email, I did
> hdparm -ti
> > under both
> > 2216 and 2217 -- they are identical -- this may be something weird
> > w/extended partitions...
>
> What nonsense. There is nothing special with extended partitions.
> Partitions influence the logical view on the disk, but not I/O.
>
> (But the outer rim of a disk is faster than the inner side.)
>
> Moreover, you report elapsed times
> 0:27, 0:22, 0:24, 0:28, 0:21, 0:24, 0:27
> where is this performance hit?
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> Please read the FAQ at http://www.tux.org/lkml/
>

2000-11-15 00:48:04

by L A Walsh

[permalink] [raw]
Subject: RE: IDE0 /dev/hda performance hit in 2217 on my HW - more info - maybe extended partitions

It seems to be the output of vmstat that isn't matching things. First it
says
it's getting near 10M/s, but if you divide 128M/27 seconds, it's more like
4.7.
So where is the time being wasted? It's not in cpu either.

Now lets look at hda7 where vmstat reported 2-3meg/sec. Again, the math
says it's a rate near 5. So it still doesn't make sense.



> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Andries Brouwer
> Sent: Monday, November 13, 2000 4:59 PM
> To: LA Walsh
> Cc: lkml
> Subject: Re: IDE0 /dev/hda performance hit in 2217 on my HW - more info
> - maybe extended partitions
>
>
> On Mon, Nov 13, 2000 at 03:47:27PM -0800, LA Walsh wrote:
>
> > Some further information in response to a private email, I did
> hdparm -ti
> > under both
> > 2216 and 2217 -- they are identical -- this may be something weird
> > w/extended partitions...
>
> What nonsense. There is nothing special with extended partitions.
> Partitions influence the logical view on the disk, but not I/O.
>
> (But the outer rim of a disk is faster than the inner side.)
>
> Moreover, you report elapsed times
> 0:27, 0:22, 0:24, 0:28, 0:21, 0:24, 0:27
> where is this performance hit?
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> Please read the FAQ at http://www.tux.org/lkml/
>

2000-11-15 00:53:36

by Andre Hedrick

[permalink] [raw]
Subject: RE: IDE0 /dev/hda performance hit in 2217 on my HW - more info - maybe extended partitions


Hi Linda,

Are you having variable transfer rates based on the zone access point?
If this is the case it is correctly reporting slow on the ID of the LBA
range v/s the OD on the media.

Regards,

Andre Hedrick
CTO Timpanogas Research Group
EVP Linux Development, TRG
Linux ATA Development