wok diff memtester/description.txt @ rev 24170

updated otf-gfs
author Hans-G?nter Theisgen
date Wed Dec 29 07:55:54 2021 +0100 (2021-12-29)
parents
children
line diff
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/memtester/description.txt	Wed Dec 29 07:55:54 2021 +0100
     1.3 @@ -0,0 +1,43 @@
     1.4 +memtester is a utility for testing the memory subsystem in a computer to
     1.5 +determine if it is faulty.
     1.6 +
     1.7 +Usage is simple for the basic case. As root, run the resulting memtester binary
     1.8 +with the following commandline:
     1.9 +
    1.10 +    memtester <memory> [runs]
    1.11 +
    1.12 +where `<memory>` is the amount of memory to test, in megabytes by default. You
    1.13 +can optionally include a suffix of B, K, M, or G (for bytes, kilobytes,
    1.14 +megabytes, and gigabytes respectively).
    1.15 +
    1.16 +`[runs]` is an optional limit to the number of runs through all tests.
    1.17 +
    1.18 +An optional `-p physaddr` argument available to cause memtester to test memory
    1.19 +starting at a specific physical memory address (by mmap(2)ing a device file
    1.20 +representing physical memory (/dev/mem by default, but can be specified with the
    1.21 +`-d device` option) starting at an offset of `physaddr`, which is given in hex).
    1.22 +
    1.23 +Note: the memory specified will be overwritten during testing; you therefore
    1.24 +*cannot* specify a region belonging to the kernel or other applications without
    1.25 +causing the other process or entire system to crash). If you use this option, it
    1.26 +is up to you to ensure the specified memory is safe to overwrite. That makes
    1.27 +this option mostly of use for testing memory-mapped I/O devices and similar.
    1.28 +Thanks to Allon Stern for the idea behind this feature. For example, if you want
    1.29 +to test a bank of RAM or device which is 64kbytes in size and starts at physical
    1.30 +address 0x0C0000 through the normal /dev/mem, you would run memtester as
    1.31 +follows:
    1.32 +
    1.33 +    memtester -p 0x0c0000 64k [runs]
    1.34 +
    1.35 +If instead that device presented its memory as /dev/foodev at offset 0, you
    1.36 +would run memtester instead as follows:
    1.37 +
    1.38 +    memtester -p 0 -d /dev/foodev 64k [runs]
    1.39 +
    1.40 +Note that the `-d` option can only be specified in combination with `-p`.
    1.41 +
    1.42 +memtester must run as user root so that it can lock its pages into memory. If
    1.43 +memtester fails to lock its pages, it will issue a warning and continue
    1.44 +regardless. Testing without the memory being locked is generally very slow and
    1.45 +not particularly accurate, as you'll end up testing the same memory over and
    1.46 +over as the system swaps the larger region.