Terminally slow (75 seconds) on some steps

Robert Vazan
2003-07-12T09:03:58Z

I am trying to debug large program and I am observing unusual slowdown.
I don't have any breakpoints, I am just running the app. I measured 75
seconds of wall clock for single click operation that takes fraction of
second outside debugger. Process time (as viewed by ps) of gdb increased
by 68 seconds. I get realtime reaction with some operations and this
delay with some other operations. When single stepping, it seems that
the more lines must be executed the more time it takes in debugger (but
this is in 1-5 seconds range).

As if gdb was emulating every instruction. I know this isn't the case.
However, breakpoints cause interrupts, so maybe gdb is being bogged down
by some other interrupts, timer maybe? Given that single step can take
one or more seconds, few timers could quickly accumulate to minute.

I have also this problem that I cannot run the program twice per
session, so I have to restart gdb and consequently reload symbols. I
have aging snapshot from 1. April 2002.