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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2020-04-07 14:45:00 +0200 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2020-04-10 10:14:29 +0200 |
| commit | cf40643937f5dd9f8df515f5ce2997ea5fc07231 (patch) | |
| tree | bf53ae5389e7993c5e27072ede3a6bd4c12fa6d9 | |
| parent | 1840148b08e115028411d77cc2558aefd4be130b (diff) | |
| download | man-pages-cf40643937f5dd9f8df515f5ce2997ea5fc07231.tar.gz | |
time_namespaces.7: Updates after feedback from Andrei Vagin
Reported-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
| -rw-r--r-- | man7/time_namespaces.7 | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/man7/time_namespaces.7 b/man7/time_namespaces.7 index dc18a4c4b2..24b98c9722 100644 --- a/man7/time_namespaces.7 +++ b/man7/time_namespaces.7 @@ -47,9 +47,11 @@ except that it also includes any time that the system is suspended. Thus, the processes in a time namespace share per-namespace values for these clocks. This affects various APIs that measure against these clocks, including: +.BR clock_gettime (2), .BR clock_nanosleep (2), .BR nanosleep (2), -.BR clock_gettime (2), +.BR timer_settime (2), +.BR timerfd_settime (2), and .IR /proc/uptime . .PP @@ -69,6 +71,10 @@ The .IR /proc/[pid]/ns/time_for_children symbolic link shows the time namespace in which the children of a process will be created. +(A process can use a file descriptor opened on +this symbolic link in a call to +.BR setns (2) +in order to move into the namespace.) .\" .SS /proc/PID/timens_offsets Associated with each time namespace are offsets, @@ -98,7 +104,13 @@ The remaining fields express the offset (seconds plus nanoseconds) for the clock in this time namespace. These offsets are expressed relative to the clock values in the initial time namespace. -In the initial time namespace, the contents of this file are as follows: +The +.I offset-secs +value can be negative. +.PP +In the initial time namespace, the contents of the +.I timens_offsets +file are as follows: .PP .in +4n .EX @@ -110,7 +122,9 @@ $ \fBcat /proc/self/timens_offsets\fP .PP In a new time namespace that has had no member processes, the clock offsets can be modified by writing newline-terminated -records of the same form to the file. +records of the same form to the +.I timens_offsets +file. The file can be written to multiple times, but after the first process has been created in or has entered the namespace, .BR write (2)s |