Waiting for pipe

[Fred Ruffet]

Hi !

I have a program, reading from a pipe, writing to a pipe. A dd writes in the input pipe, and a second dd reads output from the second pipe.

Process takes too much time, and when I look at glance, I see that my program and dds are permanently stopped by kernel scheduling while accessing the pipe resource. Finally, it takes more time wainting for pipes, than working.

Is there a wait to resolve this ?

Fred

[Dennis Handly]

The internal buffer for pipes is 8 Kb. This causes waits if the reader keeps dawdling and doesn't keep up. (What you need is MPE/iX message files that write to disk if the reader is slowpoke. ;-)

See this other thread for details:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1149390

I don't know if using nice(1) on the writer will help?

[Steven E. Protter]

Shalom Fred,

I think lowering the nice number (giving higher priority) with renice should help with scheduling issues that you report.

Though it also might help if the system were less busy.

What is the exact dd command that you are using?

SEP