[053/192] docs: proc.rst: meminfo: briefly describe gaps in memory accounting

Commit Message

Andrew Morton July 1, 2021, 1:50 a.m. UTC

From: Mike Rapoport <[e-mail]>
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/[e-mail]
Signed-off-by: Mike Rapoport <[e-mail]>
Acked-by: Michal Hocko <[e-mail]>
Reviewed-by: Matthew Wilcox (Oracle) <[e-mail]>
Acked-by: Vlastimil Babka <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: Alexey Dobriyan <[e-mail]>
Cc: Eric Dumazet <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 Documentation/filesystems/proc.rst |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Patch

--- 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.
 
 ::