Re: Suggested method for returning a string from a C program?

bart <bc@freeuk.com> writes:

On 28/03/2025 22:33, Keith Thompson wrote:

bart <bc@freeuk.com> writes:

On 28/03/2025 20:41, Scott Lurndal wrote:

[...]

The gnu compiler is not multithreaded.  The single thread was
compute bound for 13 minutes and 46 seconds.

>
So what was that -j96 about?

"-j96" is an option to GNU make, not to the compiler.  It might
invoke
gcc multiple times in parallel, but each invocation of gcc will still be
single-threaded.

>
So, is there just once instance of gcc at work during those 13
minutes, or multiple?
>
In other words, would it take longer than 13:40 mins without it, or
does it help? If -j96 makes no difference, then why specify it?

I haven't done any measurements, but I don't know what's unclear.

If a single thread was compute bound for 13:46, using "-j96"
won't make that single thread run any faster, but it can enable
"make" to do other things while that single thread is running.
It's also common to use "-j" without an argument, to run as many
jobs simultaneously as possible, or "-j$(nproc)" to run as many
parallel jobs as the number of processing units available (if you
have the "nproc" command; it's part of GNU coreutils).

I can imagine "-j" causing problems if dependencies are expressed
incorrectly, but I haven't run into such a problem myself.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */