From: Hubertus Franke <frankeh@watson.ibm.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: davidel@xmailserver.org, rml@tech9.net, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Fast Userspace Mutexes III.
Date: Tue, 5 Mar 2002 10:15:44 -0500 [thread overview]
Message-ID: <20020305151439.457E03FE06@smtp.linux.ibm.com> (raw)
In-Reply-To: <1015271393.15277.112.camel@phantasy> <20020304154848.A1055@elinux01.watson.ibm.com> <20020305154838.66c82118.rusty@rustcorp.com.au>
In-Reply-To: <20020305154838.66c82118.rusty@rustcorp.com.au>
On Monday 04 March 2002 11:48 pm, Rusty Russell wrote:
> On Mon, 4 Mar 2002 15:48:48 -0500
>
> Hubertus Franke <frankeh@watson.ibm.com> wrote:
> > Also, the check on PROT_SEM is missing. I tried this before and glibc
> > filtered these flags out when set. But effectively, one still needs to
> > check whether semaphores are allowed during the sys_futex call.
>
> Neither arch I care about (ppc, x86) needs to do anything with PROT_SEM, so
> it's OK. glibc will have to be fixed on any architectures which require
> help here, and a hook will be needed somewhere in the kernel for them.
>
> I didn't implement it because I don't *know* which archs will need
> something, and what they will need. Hence my request for arch maintainers
> to step forward (Linus said they exist, and I believe him).
>
> Hope that clarifies this particular wart...
> Rusty.
Clarifies only partially.
I agree to put it there if its not used as a means to define whether
user locks are permitted or not. If that is the intention, then the current
futex will need to check every access through find_vma(), which we
both know nobody wants to do.
So it can only be used for architectural hints, agreed ?
--
-- Hubertus Franke (frankeh@watson.ibm.com)
next prev parent reply other threads:[~2002-03-05 15:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-04 3:55 [PATCH] Fast Userspace Mutexes III Rusty Russell
2002-03-04 19:49 ` Robert Love
2002-03-04 20:13 ` Davide Libenzi
2002-03-04 20:20 ` Matthew Kirkwood
2002-03-04 20:48 ` Hubertus Franke
2002-03-04 22:15 ` Davide Libenzi
2002-03-05 1:50 ` Robert Love
2002-03-05 2:53 ` Davide Libenzi
2002-03-05 3:45 ` Rusty Russell
2002-03-05 3:55 ` Davide Libenzi
2002-03-05 6:11 ` Rusty Russell
2002-03-05 17:23 ` Davide Libenzi
2002-03-05 15:09 ` Hubertus Franke
2002-03-05 4:30 ` Edgar Toernig
2002-03-07 1:58 ` Richard Henderson
2002-03-07 2:10 ` Davide Libenzi
2002-03-05 4:48 ` Rusty Russell
2002-03-05 15:15 ` Hubertus Franke [this message]
2002-03-06 1:31 ` Rusty Russell
2002-03-05 1:34 ` Rusty Russell
2002-03-07 1:52 ` Richard Henderson
2002-03-07 3:39 ` Rusty Russell
2002-03-07 8:48 ` Richard Henderson
2002-03-07 9:17 ` Rusty Russell
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