On Sat, Jun 14, 2014 at 10:05:48PM -0500, Bruce Dubbs wrote: > Dan McGhee wrote: > > > >This concept and "-j" have now become important to me and I'd like to > >learn some more before I start. > > man make > > https://www.gnu.org/software/make/manual/html_node/Parallel.html#Parallel > I'm going off on a tangent here, and this is for beyond-BLFS,
One of the packages I build on my desktops is mediainfo (originally this was to let me check the durations of the streams in a video when I was having difficulty getting youtube to accept it - ISTR that was NOT the problem, and I now used it to check the tags in my flac files). With recent versions, this has a bash script which appears to be trying to use all the cores during the build (and I cannot see anything _obviously_ wrong in what it is doing). For me, on a box with 4 cores (real or hyperthreaded) the desktop becomes unresponsive (even the clock stops updating for long periods of time), but the build does eventually complete and the system is again usable. But on my box with only two cores it does not complete in the amount of time I have been prepared to wait. My guess is that for some reason the script decides there are far more cores than actually exist, and that is what brings the box to its knees (ISTR the code is C++, so everything probably assumes that memory is an infinite resource). In this case, I use a sed to force it to use regular "make" (and therefore -j1 because the script which runs the compile ignores $MAKEFLAGS) instead of the Zen_Make function in the tarball's script. From this, I draw two conclusions : 1. Running too many jobs in parallel _will_ bring a system to its knees. 2. Some packages are just _different_. ;-) ĸen -- Nanny Ogg usually went to bed early. After all, she was an old lady. Sometimes she went to bed as early as 6 a.m. -- http://lists.linuxfromscratch.org/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
