Badari Pulavarty <[EMAIL PROTECTED]> wrote: > > BEFORE: (without writepages support) > > > elm3b29:/mnt # touch file > elm3b29:/mnt # time /tmp/writer file > real 0m23.746s user 0m0.000s sys 0m5.020s (allocation) > elm3b29:/mnt # time /tmp/writer file > real 0m20.950s user 0m0.001s sys 0m2.278s (no alloc) > elm3b29:/mnt # time /tmp/writer file > real 0m21.030s user 0m0.001s sys 0m2.254s (no alloc) > elm3b29:/mnt # time /tmp/writer file > real 0m20.577s user 0m0.001s sys 0m2.184s (no alloc) > > > ==== > AFTER: (with writepages support) > > > elm3b29:/mnt # touch file > elm3b29:/mnt # time /tmp/writer file > real 0m23.230s user 0m0.001s sys 0m4.132s (allocation) > elm3b29:/mnt # time /tmp/writer file > real 0m20.175s user 0m0.004s sys 0m1.756s (no alloc) > elm3b29:/mnt # time /tmp/writer file > real 0m20.368s user 0m0.001s sys 0m1.696s (no alloc) > elm3b29:/mnt # time /tmp/writer file > real 0m20.626s user 0m0.002s sys 0m1.763s (no alloc)
Holy cow. I'm shocked. There's no system CPU time involved, and the user CPU time didn't change. We must be getting better I/O scheduling for some reason. I wonder what it is? That, or we're forgetting to write something ;) What journalling mode were you using? What I/O scheduler? What sort of disk system? - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
