On Wed, Nov 7, 2018 at 9:16 AM, Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > On Tue, Nov 06, 2018 at 08:01:13AM +0200, Mike Rapoport wrote: >> > 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 > > "open file descriptor" (the "a" is unnecessary) Thanks for spotting that. I had to re-read that sentence three times or so before even seeing that extra "a". >> > +contained files or subdirectories does not prevent <pid> being reused >> > +for some other process in the event that <pid> exits. Operations on >> > +open /proc/<pid> file descriptors corresponding to dead processes >> > +never act on any new process that the kernel may, through chance, have >> > +also assigned the process ID <pid>. Instead, operations on these FDs >> > +usually fail with ESRCH. > > The paragraph is a bit wordy. More pithy: > > An open file descriptor for /proc/<pid> (or any of the files or > subdirectories in it) does not prevent <pid> from being reused after > the process exits. Operations on a file descriptor referring to a dead > process usually return ESRCH. They do not act on any new process which > has been assigned the same <pid>. I'll send a new patch version --- unless we can just tweak the patch when we merge it into the tree?
