On December 8, 2018 6:23:04 PM UTC, Dale <rdalek1...@gmail.com> wrote: >Alexander Puchmayr wrote: >> Am Donnerstag, 6. Dezember 2018, 10:27:31 CET schrieb Dale: >>> Howdy, >>> >>> I mentioned in other threads that I'm doing some upgrades to my >system. >>> My first question is about a CPU upgrade. I currently have this for >my >>> CPU, from cpuinfo: >>> >>> AMD Phenom(tm) II X4 955 Processor >>> >>> I've bought but not yet installed a FX-8350 CPU. I have this in my >>> make.conf file: >>> >>> CFLAGS="-march=native -O2 -pipe" >> Compiling the whole system with -march=native might lead to troubles, > >> especially when doing a CPU change. This option means that gcc is >determining >> the type of CPU automatically and adjusts the instruction set used to >exactly >> this CPU. Although, in your case, it is highly likely that your new >CPU >> understands all commands from the old, but I wouldn't bet on it. Its >possible >> that your existing software encounters problems like "illegal >instruction" or >> the like. Very bad if your compiler crashes after CPU replacement, >then you >> cannot emerge anything. I highly recommend using CFLAGS="-O2 -pipe" >and >> nothing more, the performance difference is, if measurable at all, >negligible. >> >>> USE_CPU="fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca >cmov >>> pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt >>> pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl >nonstop_tsc >>> extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic >>> cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt >>> nodeid_msr hw_pstate npt lbrv svm_lock nrip_save" >>> >> As someone else in this thread already mentioned, USE_CPU is not >used. What >> you're looking for is CPU_FLAGS_X86=..., which defines what >cpu-specific options >> will be enabled for packages supporting it and where it makes sense. >See >> package cpuid2cpuflags for details. >> >> Regards >> Alex >> > >It seems the holiday shopping is slowing down delivery. My fan was >supposed to be here today but didn't arrive. Since I got time, I'll >change the CFLAGS for at least the @system stuff, that should get me >booted for sure. While the native setting makes things easier for >normal use, I can see the point of not using it when changing CPUs. >That is one reason for this thread. The CPUs are different and may >require some changes during the swap. > >Is there a easy way to see what if any changes will be made? I did a >emerge -UDNa @system but it's not showing any change. Does it require >a >emerge -e @system to force the change? Or is it not changing anything? > >Thanks much. Better safe than sorry. ;-) > >Dale > >:-) :-)
A CFLAGS change requires a rebuild of all packages done with gcc. I am not aware of a simple way of only doing those, so a "emerge --empty @world" will be needed. -- Joost -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
