2009/7/7 Vladislav Bolkhovitin <vst@xxxxxxxx>:Ronald Moesbergen, on 07/07/2009 10:49 AM wrote:Can you update to the latest trunk/ and send me the kernel logs from theYes I have. And the warning about missing io_context patches wasn'tHave you rebuild and reinstall SCST after patching kernel?I think, most likely, there was some confusion between the tested andThe tests above were definitely done right, I just rechecked the
patched versions of the kernel or you forgot to apply the io_context
patch.
Please recheck.
patches, and I do see an average increase of about 10MB/s over an
unpatched kernel. But overall the performance is still pretty bad.
there during the compilation.
kernel's boot after one dd with any block size you like >128K and the
transfer rate the dd reported, please?
I think I just reproduced the 'wrong' result:
dd if=/dev/sdc of=/dev/null bs=512K count=2000
2000+0 records in
2000+0 records out
1048576000 bytes (1.0 GB) copied, 12.1291 s, 86.5 MB/s
This happens when I do a 'dd' on the device with a mounted filesystem.
The filesystem mount causes some of the blocks on the device to be
cached and therefore the results are wrong. This was not the case in
all the blockdev-perftest run's I did (the filesystem was never
mounted).
Ronald.