Something to note in the original bug report is that CFLAGS chosen are not optimal for performance (`make 'CFLAGS=-Wall -g -O2 -w'`). Specifically, the `-g` and `-O2` flags should probably be changed.
`-g` [0] adds debugging info which will make the QEMU binary larger, and produce code & data to allow instrumenting and debugging at runtime. This will blow cache performance since more code & data overflow the cache. I recommend removing this all together. `-O2` [1] instructs the compiler to enable all performance options that do not involve a space-time tradeoff. Generally `-O3` is considered to produce the most "optimal" code, `-Os` is beneficial for CPUs with small caches and `-Ofast` can enable further performance potentially at the cost of program execution correctness. I recommend trying `-O3` or `-Ofast` without `-g` and retesting/rebenchmarking. [0] https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [1] https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#Optimize-Options On Wed, Mar 18, 2020 at 1:48 PM Jim Hall <jh...@freedos.org> wrote: > > > > On Wed, Mar 18, 2020 at 3:00 PM Eric Auer <e.a...@jpberlin.de> wrote: >> >> >> Hi Ralf, >> >> >> How about first installing to a directory or diskimage stored >> >> in a ramdisk on the host OS, then copying that to mass storage? >> >> > This would be a bit like the old chicken and egg problem. The time you >> > would spend to copy the contents of the FreeDOS distro from the SD card >> > to a RAM disk on the RPi is likely not much faster... >> >> I expect it to be much faster because: You only read from the >> slow SD card and you read fewer, larger files. The bad parts, >> writing many small files, would be on the fast ramdisk side. >> Also, you can start from a FreeDOS ISO on the SD card, which >> again is only one big file to copy from the web to the card. >> When done, you copy one big file, the diskimage, once from >> the ramdisk to the SD card :-) >> [..] > > > Someone had suggested that option to me - install FreeDOS to a HD image in a > RAM drive, then copy the HD image back to storage. > > But I didn't want to explain those extra steps in my article. And really, > installing FreeDOS on QEMU+RPi takes longer, but it's not "all day" long. > It's more like "start the install, and make a cup of coffee while the install > finishes." For a one-time thing, it's not too bad. > > > _______________________________________________ > Freedos-user mailing list > Freedos-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freedos-user _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
