|
From: Nicholas N. <nj...@cs...> - 2005-02-06 21:12:30
|
On Sun, 6 Feb 2005, Edward Moyse wrote: > I was surprised by that as well, but It definitely says 12x in the manual > (just checked): > "The amount of instrumentation code added varies widely between tools. At one > end of the scale, Memcheck adds code to check every memory access and every > value computed, increasing the size of the code at least 12 times, and making > it run 25-50 times slower than natively. That's code size, which only represents a fraction of a program's total memory usage. There's also data, which is usually bigger. A very rough figure to expect might be something like 3x overall. > He said that AddrCheck didn't work either, even on a machine with 3Gb of ram. > Is he correct that there is a hard-limit of 4Gb for 32 machines? Is it > believable that valgrind 2.2.0 could require 64bit machines in order to be > used on this project? (I hope not!) The amount of RAM basically doesn't matter, it's the size of the address space, which is limited to 4GB on 32-bit machines, and the kernel typically reserves the top 1GB of that. N |