Ive been seeing poor read results from tiotest in recent 2.2 kernels since 2.2.16. The performance is fine with 1 thread but slows right down with 8. I include the tiotest results here but I see similar results with iozone -t. Kernel 2.2.15 [robert@testmac25 robert]$ tiotest -f 30 -t 8 -r 0 Tiotest results for 8 concurrent io threads: ,----------------------------------------------------------------------. | Item | Time | Rate | Usr CPU | Sys CPU | +-----------------------+----------+--------------+----------+---------+ | Write 240 MBs | 20.8 s | 11.533 MB/s | 0.3 % | 14.0 % | | Read 240 MBs | 19.2 s | 12.531 MB/s | 0.3 % | 8.9 % | `----------------------------------------------------------------------' Kernel 2.2.16 [robert@testmac25 robert]$ tiotest -f 30 -t 8 -r 0 Tiotest results for 8 concurrent io threads: ,----------------------------------------------------------------------. | Item | Time | Rate | Usr CPU | Sys CPU | +-----------------------+----------+--------------+----------+---------+ | Write 240 MBs | 23.9 s | 10.058 MB/s | 0.0 % | 12.8 % | | Read 240 MBs | 105.4 s | 2.276 MB/s | 0.1 % | 2.5 % | `----------------------------------------------------------------------' Kernel 2.2.18pre15 [robert@testmac25 robert]$ tiotest -f 30 -t 8 -r 0 Tiotest results for 8 concurrent io threads: ,----------------------------------------------------------------------. | Item | Time | Rate | Usr CPU | Sys CPU | +-----------------------+----------+--------------+----------+---------+ | Write 240 MBs | 22.5 s | 10.688 MB/s | 0.3 % | 12.5 % | | Read 240 MBs | 98.0 s | 2.450 MB/s | 0.1 % | 2.7 % | `----------------------------------------------------------------------' Robert Cohen TLTSU Unix Support Australian National University - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
