Carl, Great story! I'd been looking for an excuse to get a G1. With Sage running, maybe I can deduct it as business expense.
Rob On Feb 17, 7:52 pm, Carl Witty <carl.wi...@gmail.com> wrote: > I have compiled and run Sage 3.2.3 on my T-Mobile G1 cell phone, and > large portions of it actually work. > > 300 files had failing doctests; this means that all doctests passed in > 864 files. A lot of the failing doctests are with pexpect (maxima, > gap, etc.); I don't know why these fail. When I try simple things > with gap and maxima, they do work. Many more tests fail due to > timeouts; the 300-second timeout is far too short for the G1. > (Doctesting any file with doctests takes >50 seconds; doctesting a > file with no doctests takes >4 seconds. The entire doctest run took > 270724 seconds, or a little over 3 days.) > > Unfortunately, it's far too slow to be useful for anything (just > starting Sage takes about a minute, if there's enough free memory; but > since Android likes to keep the memory full all the time, there never > is enough free memory, and it takes much longer to start). So I don't > plan to do anything further with the project. > > Of course, the sensible way to do this is to find some nice fast > computer and set up a cross-compiler. I didn't do this the sensible > way; I actually did the build on the cell phone. And of course, the > build would stop every once in a while due to a bug, which I would > then patch around. So, adding up the 14 chunks of compilation > involved, the entire compile took 20943 minutes of real time (about > 14.5 days) and 9438 minutes (about 6.5 days) of CPU time. You'll note > that the CPU time adds up to less than half of the real time; most of > the rest of the time was spent swapping. The G1 has about 100MB of > RAM; I set up a swap file on my micro-SD card, to allow the build to > proceed at all. On several files, the compiler uses more than 300MB. > While compiling those files, the CPU is typically less than 1% active; > I'm pretty sure that there were files that took more than a day to > compile. The phone was essentially unusable for smartphone activities > (web browsing, etc.) while the build was running. In fact, the whole > smartphone UI crashed and restarted on a fairly regular basis during > the build (I'm guessing it has some sort of watchdog timer and reboots > itself if it detects that some operation is taking an unreasonably > long time), but the build just continued anyway (running inside a > screen session). > > The ATLAS tuning process took about 3.2 days (with almost as much CPU > time as real time; that didn't swap much). Skimming through the logs, > I see reports of numbers like 3 to 6 MFLOPs. > > The build was performed inside a Debian armel testing chroot; it's > pretty nice being able to run real Debian on my cell phone. > (Everything works; I can ssh in and out, etc., although when it's on > the cell phone network, inbound connections are problematic because > it's behind a NAT.) > > To make the whole project even more pointless, since the phone is > running real Debian (inside the chroot), I can probably just wait a > few weeks or months for Tim Abbott to get all the portability issues > fixed in the sagemath Debian package, and then install Sage on the > phone with apt-get. > > Here's the processor: > > cwi...@localhost:/tmp$ cat /proc/cpuinfo > Processor : ARMv6-compatible processor rev 2 (v6l) > BogoMIPS : 383.38 > Features : swp half thumb fastmult edsp java > CPU implementer : 0x41 > CPU architecture: 6TEJ > CPU variant : 0x1 > CPU part : 0xb36 > CPU revision : 2 > Cache type : write-back > Cache clean : cp15 c7 ops > Cache lockdown : format C > Cache format : Harvard > I size : 32768 > I assoc : 4 > I line length : 32 > I sets : 256 > D size : 32768 > D assoc : 4 > D line length : 32 > D sets : 256 > > Hardware : trout > Revision : 0080 > Serial : 0000000000000000 > > Carl --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
