Messages in this thread | | | Date | Mon, 4 Feb 2002 23:44:58 -0500 (EST) | From | "Calin A. Culianu" <> | Subject | Re: Asynchronous CDROM Events in Userland |
| |
On Mon, 4 Feb 2002, H. Peter Anvin wrote:
> Stevie O wrote: > > > At 09:07 PM 2/3/2002 -0800, H. Peter Anvin wrote: > > > >> Rather than a signal, it should be a file descriptor of some sort, so > >> one can select() etc on it. Personally I can't imagine polling would > >> take any appreciable amount of resources, though. > > > > > > Windows 95 polls the cd-rom drive for autorun. > > It kills laptop batteries REAL quick. > > CPU & memory aren't the only resources... > > > > Does it spin up the CD-ROM doing so? > > -hpa
Probably it doesn't, but just having the cpu be non-idle when it could otherwise be idle does add up over time. In linux, polling the cdrom *seems* inexpensive enough, but if you look at 'top' it seems to average out to like 1-2% cpu time! (Ok, these stats aren't super-accurate, they're just from running 'top' with the kde autorun tool running).
[Admitedly, the autorun tool is written kind of strangely (it does one redundant ioctl, plus it wait()s on its children constantly rather than installing a signal handler), but still.. it would be nice to get those extra cycles for quake3 or wolfenstein...]
-Calin
> > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |