On 11/19/18 11:54 AM, Pavel Machek wrote: > On Mon 2018-11-05 13:22:05, Daniel Colascione wrote: >> State explicitly that holding a /proc/pid file descriptor open does >> not reserve the PID. Also note that in the event of PID reuse, these >> open file descriptors refer to the old, now-dead process, and not the >> new one that happens to be named the same numeric PID. >> >> Signed-off-by: Daniel Colascione <dancol@xxxxxxxxxx> >> --- >> Documentation/filesystems/proc.txt | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> Moved paragraphed to start of /proc/pid section; added signed-off-by. >> >> diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt >> index 12a5e6e693b6..0b14460f721d 100644 >> --- a/Documentation/filesystems/proc.txt >> +++ b/Documentation/filesystems/proc.txt >> @@ -125,6 +125,13 @@ process running on the system, which is named after the process ID (PID). >> The link self points to the process reading the file system. Each process >> subdirectory has the entries listed in Table 1-1. >> >> +Note that an open a file descriptor to /proc/<pid> or to any of its >> +contained files or subdirectories does not prevent <pid> being reused >> +for some other process in the event that <pid> exits. Operations on > > "does not" -> "may not"? > > We want to leave this unspecified, so that we can change it in future. Why can't the documentation describe the current implementation, and change in the future if the implementation changes? I doubt somebody would ever rely on the pid being reused while having the descriptor open. How would that make sense? Pavel > >
