On Mon, Oct 22, 2001 at 09:41:19PM -0400, Loren Frank wrote: > Hi all. This is a bit peripheral to rtlinux, but hopefully someone here can > help me out. > > I have written a data acquistion application using an rtlinux module, > and, while everything works well when I am not saving data to disk, during disk > writes I get pauses in the display. This is, as far as I understand it, a > result of disk write buffering, and I'm wondering if there is anything I can do > about it. > > I've tried fflush-ing the file and using setvbuf to set the file to > non-buffered mode, but neither of those had any effect on the pauses. During > the pauses the cpu usage goes up from about 50% to 100% (most of it dedicated > to the system). > > Is there any way for me to force a larger number of small disk writes so I can > minimize the gaps in the display?
Hmmm. IIRC, there's a function call fsync that you can periodically use to flush buffers, but, more importantly, I seem to remember reading about a function that keeps a given file handle unbuffered, so it's effectively always synced. I'll look it up when I go home later. Gary (-; -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
