Hi Markus, Markus Plail wrote on Sat, Oct 12 2002:
>>For example in the Linux Kernel Mailing List, and one would assume, >>that those guys know what's going on. >Yes, they should, but it seems, that it's not the case. To be honest: I am confused myself. I also have a fast ATAPI writer (PX-W4012A) running with 2.4.18. >Or how would you explain my results? I can't. Neither can I explain my own results, I also seem to be in a lucky position and not having much load during c2-scans, writing audio-CDs in DAO/SAO mode, etc. There seems to be much confusion, even on the LKML. I just hope, that this will be resolved in future kernel versions, seems to me that the current development (no more scsi cd-writers) has somehow surprised the kernel-developers. >>You will find, that cdrecord e.g. uses 5% resources, >>the other tasks maybe another 5%, but that idle-time (should be around >>90% in this example) is only 10% or less. >Well, I don't think this behaviour is wrong actually. True, and I didn't say that it was a bug. I just mentioned it as an "issue". >What really eats up CPU time in PIO mode is the interrupt handling. >So it's not cdrecord, that uses the CPU, but the system and that's >they way it is shown in top. As system time. This is correct. I only mentioned this issue, because people tend to get confused. Windoze systems e.g. behave differently, the CPU time (caused by PIO mode) is assigned to the actual task, so here cdrecord would show a system-load of e.g. 99% in Win Task-Manager. >>Again: the idle time is important. >I'd say system time is important. I simply don't know (you might be right). I just watched the "idle" time and got quite a good feedback from it during my tests with the ATAPI writer. >High system time normally means that something is wrong. In this case >PIO is used instead of DMA. I guess many roads lead to Rome ;-) High system time (or low idle time) IMHO both indicate PIO. Kind regards Frederick -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
