From: Mike Rapoport <rppt@xxxxxxxxxxxxx> Subject: docs: proc.rst: meminfo: briefly describe gaps in memory accounting Add a paragraph that explains that it may happen that the counters in /proc/meminfo do not add up to the overall memory usage. Link: https://lkml.kernel.org/r/20210421061127.1182723-1-rppt@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/filesystems/proc.rst | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/Documentation/filesystems/proc.rst~docs-procrst-meminfo-briefly-describe-gaps-in-memory-accounting +++ a/Documentation/filesystems/proc.rst @@ -933,8 +933,15 @@ meminfo ~~~~~~~ Provides information about distribution and utilization of memory. This -varies by architecture and compile options. The following is from a -16GB PIII, which has highmem enabled. You may not have all of these fields. +varies by architecture and compile options. Some of the counters reported +here overlap. The memory reported by the non overlapping counters may not +add up to the overall memory usage and the difference for some workloads +can be substantial. In many cases there are other means to find out +additional memory using subsystem specific interfaces, for instance +/proc/net/sockstat for TCP memory allocations. + +The following is from a 16GB PIII, which has highmem enabled. +You may not have all of these fields. :: _
