2009/3/3 Zhang, Austin <[email protected]>: > Are you using HDD? Yes. > Can you disable sreadahead and have a monitor again for the throughput?
Test with sreadahead disabled, the Max Disk throughput is still 8MB/s. However, I got 12MB/s , If I modify the sreadahead source code to reduce the number of thread from 4 to only 1 thread. I think maybe it is "seek time" issue. ( 4 threads to access different files on non-contiguous blocks increases the seek time ) Regards, Axel > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of > axel lin > Sent: 2009年3月2日 7:41 > To: [email protected] > Subject: [Moblin Dev] Bootchart disk throughput > > hi list, > I checked my moblin2 bootchart and found the maximum disk throughput > is only 8MB/s, > However I got 25.21 MB/sec if I test with hdparm -tT /dev/sda. > Why the number is so much different between bootchart and hdparm test? > > Below shows my disk information: > -bash-3.2# hdparm -tT /dev/sda > > /dev/sda: > Timing cached reads: 756 MB in 2.00 seconds = 378.02 MB/sec > Timing buffered disk reads: 76 MB in 3.01 seconds = 25.21 MB/sec > -bash-3.2# > > -bash-3.2# hdparm -i /dev/sda > > /dev/sda: > > Model=TOSHIBA MK8009GAH , FwRev=BS011A , > SerialNo= 38B3W2NBW > Config={ Fixed } > RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0 > BuffType=unknown, BuffSize=0kB, MaxMultSect=16, MultSect=?16? > CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=156301488 > IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} > PIO modes: pio0 pio1 pio2 pio3 pio4 > DMA modes: sdma0 sdma1 sdma2 mdma0 mdma1 mdma2 > UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 > AdvancedPM=yes: unknown setting WriteCache=enabled > Drive conforms to: Unspecified: ATA/ATAPI-1,2,3,4,5,6 > > * signifies the current active mode > > -bash-3.2# hdparm /dev/sda > > /dev/sda: > IO_support = 0 (default) > 16-bit) > HDIO_GET_UNMASKINTR failed: Inappropriate ioctl for device > HDIO_GET_DMA failed: Inappropriate ioctl for device > HDIO_GET_KEEPSETTINGS failed: Inappropriate ioctl for device > readonly = 0 (off) > readahead = 256 (on) > geometry = 9729/255/63, sectors = 156301488, start = 0 > > Regards, > Axel > _______________________________________________ > Moblin dev Mailing List > [email protected] > > To manage or unsubscribe from this mailing list visit: > https://lists.moblin.org/mailman/listinfo/dev or your user account on > http://moblin.org once logged in. > > For more information on the Moblin Developer Mailing lists visit: > http://moblin.org/community/mailing-lists > _______________________________________________ Moblin dev Mailing List [email protected] To manage or unsubscribe from this mailing list visit: https://lists.moblin.org/mailman/listinfo/dev or your user account on http://moblin.org once logged in. For more information on the Moblin Developer Mailing lists visit: http://moblin.org/community/mailing-lists
