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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-07 21:38:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-07 21:38:00 -0700
commitb66484cd74706fa8681d051840fe4b18a3da40ff (patch)
treee8215e7c25661d25f84abc4b98140c2062d6d5de /Documentation
parentc913fc4146ba7c280e074558d0a461e5c6f07c8a (diff)
parent05fd007e46296afb24d15c7d589d535e5a5b9d5c (diff)
downloadlwn-b66484cd74706fa8681d051840fe4b18a3da40ff.tar.gz
lwn-b66484cd74706fa8681d051840fe4b18a3da40ff.zip
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - fsnotify updates - ocfs2 updates - all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) console: don't prefer first registered if DT specifies stdout-path cred: simpler, 1D supplementary groups CREDITS: update Pavel's information, add GPG key, remove snail mail address mailmap: add Johan Hovold .gitattributes: set git diff driver for C source code files uprobes: remove function declarations from arch/{mips,s390} spelling.txt: "modeled" is spelt correctly nmi_backtrace: generate one-line reports for idle cpus arch/tile: adopt the new nmi_backtrace framework nmi_backtrace: do a local dump_stack() instead of a self-NMI nmi_backtrace: add more trigger_*_cpu_backtrace() methods min/max: remove sparse warnings when they're nested Documentation/filesystems/proc.txt: add more description for maps/smaps mm, proc: fix region lost in /proc/self/smaps proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self proc: add LSM hook checks to /proc/<tid>/timerslack_ns proc: relax /proc/<tid>/timerslack_ns capability requirements meminfo: break apart a very long seq_printf with #ifdefs seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char proc: faster /proc/*/status ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/filesystems/proc.txt12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index fcc1ac094282..219ffd41a911 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -515,6 +515,18 @@ be vanished or the reverse -- new added.
This file is only present if the CONFIG_MMU kernel configuration option is
enabled.
+Note: reading /proc/PID/maps or /proc/PID/smaps is inherently racy (consistent
+output can be achieved only in the single read call).
+This typically manifests when doing partial reads of these files while the
+memory map is being modified. Despite the races, we do provide the following
+guarantees:
+
+1) The mapped addresses never go backwards, which implies no two
+ regions will ever overlap.
+2) If there is something at a given vaddr during the entirety of the
+ life of the smaps/maps walk, there will be some output for it.
+
+
The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG
bits on both physical and virtual pages associated with a process, and the
soft-dirty bit on pte (see Documentation/vm/soft-dirty.txt for details).