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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 21:38:00 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 21:38:00 -0700 |
commit | b66484cd74706fa8681d051840fe4b18a3da40ff (patch) | |
tree | e8215e7c25661d25f84abc4b98140c2062d6d5de /Documentation | |
parent | c913fc4146ba7c280e074558d0a461e5c6f07c8a (diff) | |
parent | 05fd007e46296afb24d15c7d589d535e5a5b9d5c (diff) |
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.txt | 12 |
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). |