Some hints are here: https://parisc.wiki.kernel.org/index.php/Qemu
Dave On 2021-08-14 2:42 p.m., John David Anglin wrote: > I was wrong. Pasta is configured for 8 cpus. > > Dave > > On 2021-08-14 1:31 p.m., John David Anglin wrote: >> Hi Nelson, >> >> Helge Deller is the expert on this and you likely will have to wait until he >> returns from vacation >> for an answer. I think the pasta buildd running hppa emulation is >> configured for one cpu although >> I could be wrong. Performance is a little slower than a real 800 MHz PA8800 >> machine. >> >> Some profiling likely would be helpful. >> >> Dave >> >> On 2021-08-14 10:35 a.m., Nelson H. F. Beebe wrote: >>> In a previous message to the debian-hppa list today, I described how I >>> finally got a virtual machine successfully created for running Debian >>> 11 on HPPA (aka PA-RISC). >>> >>> On the same host >>> >>> Dell Precision 7920 (1 16-core CPU, 32 hyperthreads, >>> 2200MHz Intel Xeon Platinum 8253, >>> 384GB DDR-4 RAM); >>> Ubuntu 20.04.02 LTS (Focal Fossa) >>> >>> I have VMs running with QEMU emulation for Alpha, ARM64, M68K, MIPS32, >>> MIPS64, RISC-V64, S390x, and SPARC64, and most of them have quite >>> reasonable interactive performance, making it possible to use the >>> emacs editor in terminal windows and X11 windows without any serious >>> response problems. >>> >>> However, for the new Debian 11 HPPA VM, interactive performance is a >>> huge issue: shell typein sometimes gets immediate character echo, but >>> frequently gets delays of 10 to 30 seconds for each input character. >>> That makes it extremely hard for a fast typist to type commands and >>> text: one is never sure whether input keys have been dropped. >>> >>> I develop mathematical software, and a large package that I'm writing >>> for multiple precision arithmetic provides a testbed for evaluating VM >>> performance. Most of the QEMU CPU types support multiple processors, >>> but M68K and SPARC64 sun4u only permit one CPU. For HPPA, I have 4 CPUs >>> and 3GB DRAM; the latter is a hard limit imposed in QEMU source code. >>> >>> Here is a table of running the equivalent of >>> >>> date; make all check ; date >>> >>> on these systems, using QEMU-6.0.0, unless noted. Both compilations >>> and test programs are run in parallel, by internal "make -j" commands. >>> >>> make timing (wall clock) >>> >>> Debian 11 Alpha 07:43:16 -- 08:23:05 39m 49s >>> Debian 11 ARM64 07:58:02 -- 08:24:45 26m 43s >>> Debian 11 M68K 07:43:15 -- 08:30:56 47m 41s >>> Debian 11 HPPA 13:23:16 -- 21:40:19 497m 03s >>> Debian 11 HPPA 07:29:18 -- 18:07:19 638m >>> 01s [qemu-6.1.0-rc3] >>> NetBSD 9.2 HPPA 11:22:10 -- 01:25:46 843m 36s >>> Debian 11 MIPS32 09:21:49 -- 10:42:41 80m 52s >>> Debian 11 SPARC64 14:45:16 -- 06:19:00 933m 44s >>> Debian 11 SPARC64 17:57:58 -- 04:02:42 603m >>> 44s [qemu-6.1.0-rc3] >>> Ubuntu 18.04 S390x 18:34:34 -- 19:04:36 30m 02s >>> Ubuntu 20.04 S390x 18:34:35 -- 19:16:54 42m 19s >>> FreeBSD 13 RISC-V64 07:41:14 -- 08:34:00 52m 46s >>> FreeBSD 14 RISC-V64 08:35:27 -- 09:25:35 50m 08s >>> Fedora 34 RISC-V64 07:43:17 -- 08:02:55 19m 38s >>> >>> >From comparison, here are results on native hardware with local disk >>> (not NFS, unless indicated) [clock speed in GHz is abbreviated to G]: >>> >>> ArchLinux ARM32 09:57:34 -- 10:07:43 10m 09s >>> Debian 11 UltraSparc T2 08:30:54 -- 08:41:18 10m 24s >>> Solaris 10 UltraSparc T2 09:46:31 -- 09:59:32 13m 01s >>> Ubuntu 20.04 Xeon 8253 09:34:52 -- 09:35:36 0m 44s >>> CentOS 7.9 Xeon E6-1600v3 09:39:00 -- 09:39:42 0m 42s >>> CentOS 7.9 Xeon E6-1600v3 10:42:43 -- 10:43:30 0m >>> 47s [NFS] >>> CentOS 7.9 EPYC 7502 2.0G 64C/128T 10:02:01 -- 10:02:27 0m 26s >>> CentOS 7.9 EPYC 7502 2.5G 32C/64T 10:02:00 -- 10:02:25 0m 25s >>> >>> The tests produce about 62,000 total lines of text output, spread over >>> about 180 files. They read no input data, and are primarily compute >>> bound in loops with integer, not floating-point, arithmetic, using >>> 32-bit and 64-bit integer types. >>> >>> I have generated machine language for representative code from the >>> hotspot loop using the -S option of gcc and clang, and found that >>> 64-bit arithmetic is expanded inline with 32-bit instructions on >>> ARM32, HPPA, and M68K, none of which have 64-bit arithmetic >>> instructions. The loop instruction counts are comparable across all >>> of those systems, typically 10 to 20 instructions, compared to 5 or so >>> on those CPUs that have 64-bit arithmetic. >>> >>> The dramatic slowdowns on HPPA and SPARC64 are a big surprise, but the >>> HPPA slowdown matches the poor interactive response. The SPARC64 VM >>> is much more responsive interactively, and it DOES have 64-bit integer >>> arithmetic. >>> >>> I have not yet done profiling builds of qemu-system-hppa and >>> qemu-system-sparc64, but that remains an option for further >>> investigation to find out what is responsible for the slowness. >>> >>> I can also do profiling builds of parts of my test suite to see >>> whether there are unexpected hotspots on HPPA and SPARC64 that are >>> absent on other CPU types. >>> >>> I have physical SPARC64 hardware running Debian 11 and Solaris 10 on >>> identical boxes, and have done builds of TeX Live on them with no >>> difficulty. However, the slow speed of QEMU HPPA makes it impractical >>> to try TeX Live builds for Debian 11 HPPA, which is disappointing. >>> >>> Does any list member have any idea of why QEMU emulation of HPPA and >>> SPARC64 is so bad? Are there Debian kernel parameters that might be >>> tweaked? Have any of you used Debian on QEMU HPPA and seen similar >>> slowness compared to other CPU types? >>> >>> Notice from my first table above that NetBSD 9.2 on HPPA is also very >>> slow, which tends to point the finger at QEMU as the source of the >>> dismal performance, rather than the VM guest O/S. >>> >>> For the record, here is how QEMU releases downloaded from >>> >>> https://www.qemu.org/ >>> https://download.qemu.org/ >>> >>> are built here, taking the most recent QEMU release for the sample: >>> >>> tar xf $prefix/src/qemu/qemu-6.1.0-rc3.tar.xz >>> cd qemu-6.1.0-rc3 >>> unsetenv CONFIG_SITE >>> mkdir build >>> cd build >>> env CC=cc CFLAGS=-O2 ../configure --prefix=$prefix && make all -j && >>> make check >>> >>> QEMU builds require prior installation of the ninja-build package >>> available on major GNU/Linux distributions. On completion, the needed >>> qemu-system-xxx executables are present in the build subdirectory. >>> >>> On Ubuntu 20.04, the QEMU builds are clean, and pass the entire >>> validation suite without any failures. >>> >>> ------------------------------------------------------------------------------- >>> - Nelson H. F. Beebe Tel: +1 801 581 5254 >>> - >>> - University of Utah FAX: +1 801 581 4148 >>> - >>> - Department of Mathematics, 110 LCB Internet e-mail: >>> [email protected] - >>> - 155 S 1400 E RM 233 [email protected] >>> [email protected] - >>> - Salt Lake City, UT 84112-0090, USA URL: >>> http://www.math.utah.edu/~beebe/ - >>> ------------------------------------------------------------------------------- >>> > -- John David Anglin [email protected]
