Gentoo Archives: gentoo-user

From: Dale <rdalek1967@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Re: Epic list of total FAIL.
Date: Fri, 21 Aug 2015 23:39:51
Message-Id: 55D7B6B9.8010609@gmail.com
In Reply to: Re: [gentoo-user] Re: Epic list of total FAIL. by Alan Grimes
1 Alan Grimes wrote:
2 > Grant Edwards wrote:
3 >> On 2015-08-21, Alan McKinnon <alan.mckinnon@×××××.com> wrote:
4 >>
5 >>> Earlier I saw segfaults in gcc, and another poster pointed it out.
6 >>>
7 >>> When gcc segfaults, it is always suspicious mostly because the compiler
8 >>> is an app where we know the devs take extraordinary measures to prevent it.
9 >>>
10 >>> The most common cause is faulty hardware (most often memory) as gcc
11 >>> tends to use all of it in ways no other app does. The usual procedure
12 >>> at this point is to run memtest for an extended period - say 48
13 >>> hours, or even 72 for an older slow machine.
14 >> That is definitely good advice. I've run into this situation several
15 >> times. A machine had bad RAM that didn't seem to cause any problems
16 >> under "normal" operation. But, when trying to compile something large
17 >> like gcc, I would see non-repeatable segfaults (it wouldn't always
18 >> segfault at the exact same point). In those cases, I could often run
19 >> memtest for several passes and not see an error. But, _eventually_
20 >> ramtest would catch it. Run memtest for a few days. Really.
21 > Yeah, I know there's a single bit error out at the end of RAM that will
22 > appear on the third or fourth pass...
23 >
24 > I have already RMA'd half of the ram in this machine because it was
25 > giving a whole fist-full of errors across two sticks... I run the rusty
26 > old bus on the CPU ( SIX CORES!!!!) a bit harder than it was intended
27 > in order to keep up with the new junk. My previous machine had ECC. =(
28 >
29 > I was advised to just jack the voltage a little bit and live with it. I
30 > guess I'd better run more tests and see what the situation is....
31 >
32 > It just doesn't seem reasonable to demand that every bit in a 32
33 > gigabyte memory bank be absolutely perfect....
34 >
35
36
37 You know those multi terabyte hard drives they make, every bit of those
38 platters that are actively in use must work perfectly. If just one
39 thing, just one tiny bit, is not working correctly, you get bad data.
40 With computers, one bit of bad data means something doesn't work be it
41 hard drives or memory or even the CPU. You may can live with it on
42 widoze but not Linux. Linus maximizes the use of memory more so than
43 windoze. I have 16Gbs of ram here. Even if I don't compile anything,
44 eventually all my memory will be used by cache if nothing else. Once
45 that cache hits a bad spot, there is trouble.
46
47 Might I also add, whoever told you to live with it, I hope they don't
48 work on airplanes and I wouldn't take advice from them to much on puter
49 stuff in the future.
50
51 Just my $0.02 worth.
52
53 Dale
54
55 :-) :-)