On Nov 28, 2011 3:21 AM, "Michael Mol" <mike...@gmail.com> wrote: > > On Sun, Nov 27, 2011 at 12:56 PM, Pandu Poluan <pa...@poluan.info> wrote: > > On Nov 27, 2011 5:12 PM, "Michael Mol" <mike...@gmail.com> wrote: > > [snip] > > > > > Here's my experience: > > > > I always experience emerge failures on my Gentoo VMs if I use MAKEOPTS=-j>3. > > Not all packages, but many. Including, IIRC, glibc and gcc. > > In my barebones 177-package state, I didn't get any build failures > from parallel building, either via emerge -j or make -j. I did get one > failure when I went to install X that worked fine on the second > attempt. >
And in my barebones system (172 packages), there are several packages that reliably fail, even when emerged on their own *sigh* > > This happens even if I make sure that there's just one emerge job being > > done. And this happens even if I allocate more vCPUs than -j, on VMware and > > XenServer alike. > > FWIW, I've been running with MAKEOPTS=-j10 on my Phenom 9650 for over > a year. It's very rare that something breaks due to the parallel > build. I think it's happened perhaps three times, and each time was > resolvable with a retry. YMMV, of course; race conditions are finicky. > I have a hunch that the hypervisor had some effects. Most likely, another VM in the same host has a high enough load that necessitates the Gentoo VM to be shifted to another (physical) core, and this messes up the timing. MAKEOPTS=-j3 always succeeds, though. So I'm disinclined to delve deeper into the issue. > > I don't know where the 'blame' lies, but I've found myself standardizing on > > MAKEOPTS=-j3, and PORTAGE_DEFAULT_OPTS="--jobs > > --load-average=<1.6*num_of_vCPU>" > > > > (Yes, no explicit number of jobs. The newer portages are smart enough to > > keep starting new jobs until the load number is reached) > > Sweet; I didn't know about Portage's --load-average; I'll definitely > switch to that instead of -j. Load-driven make plus load-driven > portage should work beautifully on my system. > > I'll steal your 1.6 factor, and give: > MAKEOPTS=-j <2*N> -l <1.6*N) > PORTAGE_DEFAULT_OPTS="--jobs --load-average<1.6*N>" > a try. > Make sure that make supports non-integer values for -l, though. > How does that interact with distcc, by the way? I've got two of these > octo-core Xeon boxes, and I've still got my Phenom 9650--distcc on my > home network should become very, very nice. And this box is consuming > 255W at the wall with monitor off, 326W with monitor on. That's not > bad. Though perhaps I should move to an apartment where heat isn't > free... > Well, I don't use distcc, so I can't speculate. But with plain single system compilation, my settings have been serving me real well :-) Rgds,
