Dan Muresan wrote: > > I haven't measured it, but my educated guess is that if you're > > reading 16384 frames at a time from a FLAC file on current hardware, > > then the difference between reading st_blksize sized blocks and > > Uh, actually no. If one reads 4096, 2048, or 1024 frames the result is > the same -- 4 bytes less than st_blksize -- EVERY syscall. Try it. In > any case, I didn't optimize anything like that yet. It was a design > discussion. I was saying that's one more reason why it's good to have > the VIO layer, since there is no userspace cache. > > > non-st_blksize sized blocks will be absolutley swamped, by disk > > latencies, cache latencies, scheduling latencies and file > > decoding overhead. > > You seem to mix up latency and CPU load? A program can have low > latency, yet high(er than necessary) CPU load.
I think you missed the point. The point is that if you set out to measure the difference (in CPU load or in latency) between reading st_blksize size blocks and st_blocksize - 4 blocks at the libsndfile API level, your measurements would be so swamped with noise from other factors that any differences would be statistically irrelevant. Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/ _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
