Hello
One short Question. When setting readahead with hdparm to a value
> 128 i got:
/dev/hde:
setting fs readahead to 8192
BLKRASET failed: Invalid argument
readahead = 128 (on)
/dev/hde:
Timing buffered disk reads: 154 MB in 3.03 seconds = 50.83 MB/sec
/dev/hde:
Timing buffered disk reads: 144 MB in 3.00 seconds = 48.00 MB/sec
/dev/hde:
Timing buffered disk reads: 148 MB in 3.00 seconds = 49.33 MB/sec
does this meen the disks cannot more then 128, or the ide-chipset? or is
it for the filesystem? (disks are on a promise fasttrack controller#)
andi
Am Mit, den 31.12.2003 schrieb Paolo Ornati um 15:50:
> On Wednesday 31 December 2003 09:36, Linus Torvalds wrote:
> > Ok, I've merged a lot of pending patches into 2.6.1-rc1, and will now
> > calm down for a while again, to make sure that the final 2.6.1 is ok.
> >
> > Most of the updates is for stuff that has been in -mm for a long while
> > and is stable, along with driver updates (SCSI, network, i2c and USB).
> >
> > Linus
> >
> > ----
>
> With 2.6.1-rc1 I have noticed a strange IDE performance change.
>
> Results of "hdparm -t /dev/hda" with 2.6.0 kernel:
> (readahead = 256): ~26.31 MB/s
> (readahead = 128): ~31.82 MB/s
>
> PS = readahead is set to 256 by default on my system, 128 seems to be the
> best value
>
> Results of "hdparm -t /dev/hda" with 2.6.1-rc1 kernel:
> (readahead = 256): ~26.41 MB/s
> (readahead = 128): ~26.27 MB/s
>
> Setting readahead to 128 doesn't have the same effect with the new kernel...
>
> INFO on my HD:
>
> /dev/hda:
> multcount = 16 (on)
> IO_support = 1 (32-bit)
> unmaskirq = 1 (on)
> using_dma = 1 (on)
> keepsettings = 0 (off)
> readonly = 0 (off)
> readahead = 128 (on)
> geometry = 38792/16/63, sectors = 39102336, start = 0
>
> /dev/hda:
>
> Model=WDC WD200BB-53AUA1, FwRev=18.20D18, SerialNo=WD-WMA6Y1501425
> Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq }
> RawCHS=16383/16/63, TrkSize=57600, SectSize=600, ECCbytes=40
> BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
> CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=39102336
> IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
> PIO modes: pio0 pio1 pio2 pio3 pio4
> DMA modes: mdma0 mdma1 mdma2
> UDMA modes: udma0 udma1 udma2 udma3 *udma4 udma5
> AdvancedPM=no WriteCache=enabled
> Drive conforms to: device does not report version: 1 2 3 4 5
>
>
> IDE controller:
>
> 00:04.1 IDE interface: VIA Technologies, Inc. VT82C586/B/686A/B PIPC Bus
> Master IDE (rev 10) (prog-if 8a
> [Master SecP PriP])
> Flags: bus master, medium devsel, latency 32
> I/O ports at b800 [size=16]
> Capabilities: [c0] Power Management version 2
>
>
> I don't understand how this happens... the only changes to IDE driver seems
> to be these:
>
> >
> > Summary of changes from v2.6.0 to v2.6.1-rc1
> > ============================================
> > Andrew Morton:
> > o Can't disable IDE DMA
> > o IDE MMIO fix
> > o IDE capability elevation fix
> >
> > Linus Torvalds:
> > o Make IDE DRQ and READY timeouts longer
>
> For my tests I have used this stupid shell script:
>
> #!/bin/bash
>
> echo "HD test for linux `uname -r`"
> echo
>
> ra=8
> for i in `seq 12`; do
> echo "READAHEAD = $ra";
> hdparm -a $ra /dev/hda;
> for j in `seq 3`; do
> hdparm -t /dev/hda;
> done;
> ra=$(($ra*2));
> done
>
> Results for 2.6.0 && 2.6.1-rc1 are attached.
>
> Bye