Re: 2.6.20-rc2+: CFQ halving disk throughput.

From: Mark Lord
Date: Tue Jan 02 2007 - 12:36:00 EST


Tejun Heo wrote:

OT but care to make -i and -I work equivalently? Such that -i reports
more detailed info and user can dump stored id block.

hdparm -I works just fine now.

hdparm -i requires the HDIO_GET_IDENTITY ioctl() from drivers/ide,
to retrieve the "boot time" copy of the identify block, before any
mods are made by the driver. But in recent years, drivers/ide has
broken it, in that it tries to maintain the "boot time" copy in sync
with the on-drive copy. Kinda makes -i pointless.

Is there a way to retrieve the libata cached copy of the ID block?
How?

Support for IDENTIFY PACKET DEVICE would be nice too.

It already does that, using HDIO_DRIVE_CMD to retrieve it
in the same way as for regular IDENTIFY DEVICE commands.

In hdparm-7.0, I'll have it use ATA passthrough when possible
for most/all commands.

Cheers
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