Date: Sun, 26 Apr 2015 23:05:50 +0200 From: =?UTF-8?Q?Fernando_Apestegu=C3=ADa?= <fernando.apesteguia@gmail.com> To: galtsev@kicp.uchicago.edu Cc: User Questions <freebsd-questions@freebsd.org> Subject: Re: Debugging bad memory problems Message-ID: <CAGwOe2a7UZxSsaV4T2pcU0K1MA-OH1=123pb%2BsM=pTgSFEDLFg@mail.gmail.com> In-Reply-To: <5480.69.209.235.143.1430078703.squirrel@cosmo.uchicago.edu> References: <CAGwOe2Y%2BRuT7MuCTBq_swn-Ny-BS-WH1J=bZTbE9L4tuv8LmCA@mail.gmail.com> <5480.69.209.235.143.1430078703.squirrel@cosmo.uchicago.edu>
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On Sun, Apr 26, 2015 at 10:05 PM, Valeri Galtsev <galtsev@kicp.uchicago.edu> wrote: > > On Sun, April 26, 2015 12:11 pm, Fernando Apestegu=C3=ADa wrote: >> Hi, >> >> I suspect my old and beloved AMD64 laptop is suffering from bad memory >> problems: I get random crashes of well tested programs like sh, which, >> etc even when I executed some of them from /rescue. > > If RAM is a suspect the first thing I would do is re-seat memory modules. > Open the box. (Observe static precautions!) Remove memory modules. Instal= l > them again. > > Do memtest86 (by booting into memtest86, you can have that in your boot > options, or you can boot off external media as others suggested). > > If you still have problems: try to run with one memory module instead of > two. At some point when they went to higher RAM speeds memory bus > amplifier became more fragile (some chips, some manufacturers, as not it > is part of CPU, this may be true only about some of the CPU models). You > sometimes can slightly fry it if you merely leave laptop running on > battery, letting battery run down and laptop powering off due to that. > With some of chips this may lead to slightly frying it - memory controlle= r > portion of it, address bus amplifier in particular. Bus amplifier becomes > slightly lower frequency, which results in poorer handling capacitive loa= d > (which is larger if you have more RAM), and it is marginally OK, > occasionally having address errors. Going to one module may resolve this. > You will know if this is likely the case if memtest86 is successful with > each of single RAM modules, but fails (in random places, often not > reproducible) with both. > > Good luck! I booted from a memtest CD-ROM. It passed a couple of tests fine and then it rebooted while doing a "bit fade" test at around 93%. Removing the modules is tricky since this laptop has screws all around in dark corners (even removing the battery needs a screw driver). I will try to limit physical memory with hw.physmem and see if it makes any difference. Thanks! > > Valeri > >> >> I wanted to check the memory banks. I installed >> /usr/ports/sysutils/memtest86+ and try to run it at boot. According to >> the documentation, from the boot loader prompt: >> >> unload >> load /boot/opt/memtest86+ >> boot >> >> But at the time of loading the file, the laptop reboots. >> >> I also tried /usr/ports/sysutils/memtest. But when I run it (as root), I >> get: >> >> $memtester 1G >> >> memtester version 4.3.0 (64-bit) >> Copyright (C) 2001-2012 Charles Cazabon. >> Licensed under the GNU General Public License version 2 (only). >> >> pagesize is 4096 >> pagesizemask is 0xfffffffffffff000 >> want 1024MB (1073741824 bytes) >> got 1024MB (1073741824 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073737728 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073733632 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073729536 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073725440 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073721344 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073717248 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073713152 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073709056 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073704960 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073700864 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073696768 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073692672 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073688576 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073684480 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073680384 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073676288 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073672192 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073668096 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073664000 bytes), trying mlock ...too many pages, >> reducing... >> got 1023MB (1073659904 bytes), trying mlock ...too many pages, >> reducing... >> >> ... >> ... >> >> got 0MB (73728 bytes), trying mlock ...too many pages, reducing... >> got 0MB (69632 bytes), trying mlock ...too many pages, reducing... >> got 0MB (65536 bytes), trying mlock ...locked. >> >> Any help with these two problems or any alternative programs? >> >> Thanks in advance. >> _______________________________________________ >> freebsd-questions@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >> To unsubscribe, send any mail to >> "freebsd-questions-unsubscribe@freebsd.org" >> > > > ++++++++++++++++++++++++++++++++++++++++ > Valeri Galtsev > Sr System Administrator > Department of Astronomy and Astrophysics > Kavli Institute for Cosmological Physics > University of Chicago > Phone: 773-702-4247 > ++++++++++++++++++++++++++++++++++++++++
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