Summary: dma not enabled for IDE hard drives
Kernel Version: 2.5.66
Status: NEW
Severity: normal
Owner: bugme-janitors@lists.osdl.org
Submitter: freelsjd@ornl.gov
Distribution: Debian/Sid
Hardware Environment: dual 2.4Ghz Xeon, SE7500CW2 MB, all Intel
Promise PDC20267 ATA-100 ide channels in
non-RAID mode
Software Environment: testing with hdparm 5.2-1 of Debian/Sid
Problem Description:
I have similar .config settings for both the 2.4.20 and the 2.5.66
kernels with the identical machine. Under 2.4.20, I do get dma enabled
and see good performance (Mb/s) from the hard disk I/O.
However, under the 2.5.66 kernel, dma is not enabled and the performance
of the hard drives is poor (~2-3 Mb/s under 2.4.20 versus ~30 Mb/s under
2.5.66). The "hdparm -I /dev/hda" command confirms that dma is not
enabled under 2.5.66, but is under 2.4.20.
Steps to reproduce:
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