wok view memtester/description.txt @ rev 20645
updated hostapd (2.6 -> 2.7)
| author | Hans-G?nter Theisgen |
|---|---|
| date | Fri Jan 11 16:39:21 2019 +0100 (2019-01-11) |
| parents | |
| children |
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1 memtester is a utility for testing the memory subsystem in a computer to
2 determine if it is faulty.
4 Usage is simple for the basic case. As root, run the resulting memtester binary
5 with the following commandline:
7 memtester <memory> [runs]
9 where `<memory>` is the amount of memory to test, in megabytes by default. You
10 can optionally include a suffix of B, K, M, or G (for bytes, kilobytes,
11 megabytes, and gigabytes respectively).
13 `[runs]` is an optional limit to the number of runs through all tests.
15 An optional `-p physaddr` argument available to cause memtester to test memory
16 starting at a specific physical memory address (by mmap(2)ing a device file
17 representing physical memory (/dev/mem by default, but can be specified with the
18 `-d device` option) starting at an offset of `physaddr`, which is given in hex).
20 Note: the memory specified will be overwritten during testing; you therefore
21 *cannot* specify a region belonging to the kernel or other applications without
22 causing the other process or entire system to crash). If you use this option, it
23 is up to you to ensure the specified memory is safe to overwrite. That makes
24 this option mostly of use for testing memory-mapped I/O devices and similar.
25 Thanks to Allon Stern for the idea behind this feature. For example, if you want
26 to test a bank of RAM or device which is 64kbytes in size and starts at physical
27 address 0x0C0000 through the normal /dev/mem, you would run memtester as
28 follows:
30 memtester -p 0x0c0000 64k [runs]
32 If instead that device presented its memory as /dev/foodev at offset 0, you
33 would run memtester instead as follows:
35 memtester -p 0 -d /dev/foodev 64k [runs]
37 Note that the `-d` option can only be specified in combination with `-p`.
39 memtester must run as user root so that it can lock its pages into memory. If
40 memtester fails to lock its pages, it will issue a warning and continue
41 regardless. Testing without the memory being locked is generally very slow and
42 not particularly accurate, as you'll end up testing the same memory over and
43 over as the system swaps the larger region.