On my Ubuntu 12.04 system it is running a stock 3.2.x kernel (uname -r = 3.2.0-32-generic). When I cat /proc/meminfo I see what appears to be two undocumented fields: 1) Active(anon) and 2) Active(file); the sum of which equal Active. Is the kernel documentation out of date on this subject or am I looking in the wrong place? I would like to know what Active(anon) and Active(file) mean in /proc/meminfo. ************************************************************************* You can stop reading: The following are my own investigations in case you're interested. Here is a reference to the currently documented values in the Linux Kernel source tree for the latest stable 3.2.y kernel. http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=blob;f=Documentation/filesystems/proc.txt;h=0ec91f03422e5befe8dd7f69d22dec4a22250f69;hb=refs/heads/linux-3.2.y#l671 Here's a pastebin of my current /proc/meminfo http://fpaste.org/Og5t/ There appear to be several other undocumented fields when comparing my /proc/meminfo file and the documentation in the kernel source. anon in Active(anon) is likely referring to anonymous memory which is essentially heap/stack memory which is allocated by programs using malloc. It basically is memory with no filesystem associations. file in Active(file) is likely referring to the File Cache which contains disk and network filesystem data and metadata (can include files loaded into memory and possibly execution instructions loaded from disk?). I inferred the anonymous/file from the following links. - http://oreilly.com/catalog/spt2/chapter/ch04.html#21495 - http://linux-mm.org/PageReplacementDesign I was looking through some of the kernel source and did find the strings where Active(anon) and other values are listed. See fs/proc/meminfo.c http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=blob;f=fs/proc/meminfo.c;h=80e4645f7990cf4cc0e636a7c19f9840503cdd42;hb=refs/heads/linux-3.2.y#l52 I can make some educated guess as to what they mean given what I already know but I'd like to know if anyone else has an exact answer with where to find this information. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
