14.09.2020 4:30, Charles Lecklider via freebsd-stable wrote: > On 2020-09-01 03:20, Eugene Grosbein wrote: >> CPU: Geode(TM) Integrated Processor by AMD PCS (499.91-MHz 586-class CPU) >> Origin="AuthenticAMD" Id=0x5a2 Family=0x5 Model=0xa Stepping=2 >> Features=0x88a93d<FPU,DE,PSE,TSC,MSR,CX8,SEP,PGE,CMOV,CLFLUSH,MMX> >> AMD Features=0xc0400000<MMX+,3DNow!+,3DNow!> >> >> Of course, its NanoBSD image is built with CPUTYPE=i586 as well as installed >> packages. > > You've got CMOV so you'll be fine with 11.4-RELEASE, whereas I don't: > > CPU: Pentium/P55C (232.68-MHz 586-class CPU) > Origin="GenuineIntel" Id=0x543 Family=0x5 Model=0x4 Stepping=3 > Features=0x8003bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,APIC,MMX> > > Getting 11.4 to work has been a *major* undertaking: > > Setting CPUTYPE in `make.conf` doesn't set -march for the kernel build > tools, so while you can compile world and kernel for i386, you can't > actually link it to create a working kernel on a real i586 (I found that > out with `/usr/obj` and `/usr/src` mounted over NFS).
Build time for modern FreeBSD version is too gross and needs way too much memory, so I stopped building image for my i586 hardware "in place" quite long ago. I use my i7-based desktop to build NanoBSD image for its upgrade, it works just fine by default setting ARCH/TARGET_ARCH to i386 and correct CPUTYPE. > Don't try -Os or -Oz (which really do help on a real i586) - ZFS will > wedge quickly. Currently i586-class CPU needs as many speed improvements as possible and I was told that -Os might drop performance comparing with -O2, so why bother? > 11.4 i386 doesn't honour `vfs.zfs.arc_max` in any meaningful way > resulting in one of the `find`s in periodic security wedging ZFS. Been there, seen that. The problem pre-dates 11.x series and appeared in 10.x. It was much better in times of 9.x, though. > By ZFS wedging I mean something gets stuck on zio->i having eaten all of > kmem (I presume - on the real i586 I expect ~200M in ARC would do that > and that's what `top` shows) and that's it for the machine - it doesn't > panic, but there's no more disk IO either. > This also happens in VirtualBox with 4GB RAM, so it's not a hardware > problem. > > To get 11.4 to behave itself (and it's only been 72 hours so still early > days) I've had to set: > > options KSTACK_PAGES=4 This is default for 12.x/i386 but was not merged to stable/11. > and > > kern.maxvnode="1024" > vm.kmem_size="330M" > vm.kmem_size_max="330M" > vfs.zfs.arc_max="125M" > vfs.zfs.arc_meta_limit="16M" > > I had to set kmem for 11.3 but not the rest. You might find useful these also: vfs.zfs.vdev.cache.size="8M" vfs.zfs.prefetch_disable="1" And for kernel config: options KVA_PAGES=512 This makes ZFS more stable giving it bigger kernel virtual area with less utilization for it. > TL;DR: I'd avoid 11.4 i386 as it doesn't appear to have been tested on > i486/i586 at all. Finally I gave up running ZFS for vmem-contrained systems, e.g. I moved my i386 virtual machines that benefit from ZFS compression to amd64. As for real i586-class hardware uncapable of Long Mode, I do not use ZFS at all, UFS2/async+gjournal works just fine there including WiFi, IPSec etc. but no ZFS. _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
