Re: Copy alist instead of deep copy on Grob clone (issue 561640045 by address@hidden)

[Werner LEMBERG]

>> Have you ever tried valgrind's `callgrind` tool for profiling (and
>> using `kcachegrind` for displaying the results)?  While very slow
>> it would avoid temperature issues and the like – no need to call it
>> multiple times to get reliable values.
> 
> What magic does callgrind do to prevent influence of frequency
> changes from the processor?

It emulates the CPU.

  https://en.wikipedia.org/wiki/Valgrind

> Or cache misses due to the OS migrating the process from one core to
> another?

Here I'm completely clueless, sorry.  However, valgrind also comes
with the `cachegrind` tool, which is tagged as "a cache and
branch-prediction profiler".  Maybe this helps:

  
https://stackoverflow.com/questions/32542164/using-valgrind-to-measure-cache-misses

For FreeType, I'm frequently using valgrind's `memcheck` mode, which
is quite valuable in finding memory problems of all kinds.  It is a
good complementary tool to gcc's (and clang's) ubsan and friends.


    Werner