Much of the information here is used by the free, top, and ps
commands. In fact, the output of the free command is similar in
appearance to the contents and structure of /proc/meminfo. But by
looking directly at /proc/meminfo, more details are revealed:
MemTotal — Total amount of physical RAM, in kilobytes.
MemFree — The amount of physical RAM, in kilobytes, left unused by the
system.
Buffers — The amount of physical RAM, in kilobytes, used for file
buffers.
Cached — The amount of physical RAM, in kilobytes, used as cache
memory.
SwapCached — The amount of swap, in kilobytes, used as cache memory.
Active — The total amount of buffer or page cache memory, in
kilobytes, that is in active use. This is memory that has been
recently used and is usually not reclaimed for other purposes.
Inactive — The total amount of buffer or page cache memory, in
kilobytes, that are free and available. This is memory that has not
been recently used and can be reclaimed for other purposes.
HighTotal and HighFree — The total and free amount of memory, in
kilobytes, that is not directly mapped into kernel space. The
HighTotal value can vary based on the type of kernel used.
LowTotal and LowFree — The total and free amount of memory, in
kilobytes, that is directly mapped into kernel space. The LowTotal
value can vary based on the type of kernel used.
SwapTotal — The total amount of swap available, in kilobytes.
SwapFree — The total amount of swap free, in kilobytes.
Dirty — The total amount of memory, in kilobytes, waiting to be
written back to the disk. Writeback — The total amount of memory, in
kilobytes, actively being written back to the disk.
Mapped — The total amount of memory, in kilobytes, which have been
used to map devices, files, or libraries using the mmap command.
Slab — The total amount of memory, in kilobytes, used by the kernel to
cache data structures for its own use.
Committed_AS — The total amount of memory, in kilobytes, estimated to
complete the workload. This value represents the worst case scenario
value, and also includes swap memory. PageTables — The total amount of
memory, in kilobytes, dedicated to the lowest page table level.
VMallocTotal — The total amount of memory, in kilobytes, of total
allocated virtual address space.
VMallocUsed — The total amount of memory, in kilobytes, of used
virtual address space.
VMallocChunk — The largest contiguous block of memory, in kilobytes,
of available virtual address space.
HugePages_Total — The total number of hugepages for the system. The
number is derived by dividing Hugepagesize by the megabytes set aside
for hugepages specified in /proc/sys/vm/hugetlb_pool. This statistic
only appears on the x86, Itanium, and AMD64 architectures.
HugePages_Free — The total number of hugepages available for the
system. This statistic only appears on the x86, Itanium, and AMD64
architectures.
Hugepagesize — The size for each hugepages unit in kilobytes. By
default, the value is 4096 KB on uniprocessor kernels for 32 bit
architectures. For SMP, hugemem kernels, and AMD64, the default is
2048 KB. For Itanium architectures, the default is 262144 KB. This
statistic only appears on the x86, Itanium, and AMD64 architectures.
For Itanium architectures, the default is 262144 KB.
- Should that be 262144 bytes? – Michael – 2016-05-13T00:09:45.823