Date: Mon, 26 Jun 2000 15:04:49 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: John Polstra <jdp@polstra.com> Cc: chris@calldei.com, hackers@FreeBSD.ORG Subject: Re: struct proc Message-ID: <200006262204.PAA30219@apollo.backplane.com> References: <3957ABBD.6010407@mail.ru> <20000626111453.E20702@holly.calldei.com> <200006262020.NAA16125@vashon.polstra.com>
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:> p is the process that made the syscall, curproc is the current
:> running process. You should be using p for the process that
:> called my_syscall.
:
:Since only one process can enter the kernel at a time (currently),
:and p is the process that made the system call, it is also the
:current process. I claim that (p == curproc) in this example, and
:that it would be better to code with p than with curproc.
:
:John
: John Polstra jdp@polstra.com
:...
Even in an MP system, curproc is not going to be ripped out from
under a syscall. p will always be curproc. (curproc in an MP
system is a per-cpu variable).
This whole p vs curproc thing is a huge mess. 95% of the time
p == curproc. The only places where it might not is in I/O ops
that are completed by an interrupt or (in the case of NFS) some
other process.
-Matt
Matthew Dillon
<dillon@backplane.com>
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