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Subject: Re: RFC [patch 13/34] PID Virtualization Define new task_pid api
From: Trond Myklebust <trond.myklebust@fys.uio.no>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Arjan van de Ven <arjan@infradead.org>,
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Date: Wed, 25 Jan 2006 10:10:11 -0500
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On Wed, 2006-01-25 at 02:58 -0700, Eric W. Biederman wrote:
> >> On Maw, 2006-01-24 at 12:26 -0700, Eric W. Biederman wrote:
> >> > There is at least NFS lockd that appreciates having a single integer
> >> > per process unique identifier.  So there is a practical basis for
> >> > wanting such a thing.

The NFS lock manager mainly wants a unique 32-bit identifier that can
follow clone(CLONE_FILES). The reason is that the Linux VFS is forced to
use the pointer to the file table as the "process identifier" for posix
locks (i.e. fcntl() locks).

Cheers,
  Trond