Deskin Miller wrote: > On 6/4/07, Miguel Bazdresch <[EMAIL PROTECTED]> wrote: >> Deskin Miller wrote: >>> [ should the book say anything about 'make -j X' on multi-core systems? ] >> ['make -j X' where X is number of cores is more or less optimal...] >> There are issues when running make with other than -j1. Some package builds will fail when make tries a parallel build. You can check out jhalfs' optimize section which has an incomplete black list of packages with MAKEFLAG issues. >> As far as mentioning it in the book... I'm not enthusiastic, since >> it's basic knowledge of how your computer works... OTOH we already >> say some pretty basic things, and the proliferation of multicore >> CPUs might warrant a mention of make -j. > This also applies to the 'older' Hyper-Threading Intel products. I saw a noticeable reduction in compile times when I went to -j2.
> The concept of matching 'make -j X' to the number of cores isn't > difficult, but I'd argue it's worth a mention as much for those who > haven't had cause to wonder about 'make's various flags before, as to > give people a lesson in multi-core theory: in my own case, as a Linux > user for several years now, make -j was an eye-opener when I came > across it only yesterday, since I had never had a SMP or multi-core > system until very recently upon which to compile, and thus unwittingly > filtered out from my Linux knowledge the make flags which didn't have > any use to me, until now. > > In short: say it for those who lack 'make' knowledge, as well as those > who lack 'multi-core' knowledge. > > -Deskin Miller -- http://linuxfromscratch.org/mailman/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
