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From: "Peter Wächtler" <pwaechtler@loewe-komp.de>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-kernel@vger.kernel.org,
	Hubertus Franke <frankeh@watson.ibm.com>,
	lse-tech@lists.sourceforge.net
Subject: Re: furwocks: Fast Userspace Read/Write Locks
Date: Thu, 07 Mar 2002 13:40:49 +0100	[thread overview]
Message-ID: <3C875FD1.4040904@loewe-komp.de> (raw)
In-Reply-To: <E16iwkE-000216-00@wagner.rustcorp.com.au>

Rusty Russell wrote:

> This is a userspace implementation of rwlocks on top of futexes.
> 

With the futex approach in mind: Does anybody think it's desirable to have

pthread_cond_wait/signal and pthread_mutex_* with inter process scope build
into the kernel as system call?

The only issue I see so far, is that libpthread should get a "reserved" namespace
entry ( /dev/shm/.linuxthreads-locks ?) to hold all the PTHREAD_PROCESS_SHARE
locks/condvars.

OTOH Irix seems to implement inter process locks as syscall, so that the kernel does
all the bookkeeping. That approach denies a malicious program to trash all locks
in the system...

Hmh, then we could implement a per user /dev/shm/.linuxthreads-lock-<uid> with
tight permissions?

What do you think?


  reply	other threads:[~2002-03-07 12:41 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-03-07 12:11 furwocks: Fast Userspace Read/Write Locks Rusty Russell
2002-03-07 12:40 ` Peter Wächtler [this message]
2002-03-07 14:41   ` Hubertus Franke
2002-03-07 12:50 ` Arjan van de Ven
2002-03-07 15:33   ` Hubertus Franke
2002-03-07 15:42     ` Arjan van de Ven
2002-03-07 19:11       ` Hubertus Franke
2002-03-07 20:17         ` H. Peter Anvin
2002-03-08  6:27           ` Rusty Russell
2002-03-08  6:29             ` H. Peter Anvin
2002-03-08  7:09               ` Rusty Russell
2002-03-08 19:32             ` Jamie Lokier
2002-03-08  1:22     ` Rusty Russell
2002-03-08  3:26       ` H. Peter Anvin
2002-03-08  9:21       ` Peter Wächtler
2002-03-08 18:13         ` Hubertus Franke
2002-03-09  4:50         ` Rusty Russell
2002-03-11 18:47           ` Hubertus Franke
2002-03-07 15:28 ` Hubertus Franke

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