haynes%ucsce.ucscc.UUCP%Berkeley@ucscc.UUCP (01/30/85)
<> This idea comes from the dear old Burroughs B5500 Have a global word (might as well be 64 bits, they're cheap) and call it options. Make a system call or ioctl that can set and clear the bits of options and can read the contents. Make a nice command for diddling and displaying the bits. You could do this with adb, but we're talking about a nice system, so you might as well go all the way. Give each bit of the option word a name, and write some macros so you can refer to them by name. Now you put printfs or experimental code into the kernel, and have each one controlled by a bit in the option word. Use you command to turn the option on when you want to see what's going on and turn it back off when you have enough data. Might as well use some of the option bits to control printfs that are already in the system. Would be a convenient way to turn off file system full messages or table full messages when you already know about the problem and are trying to do something about it. ucbvax!ucscc!haynes