From: Christoph Hellwig <hch@lst.de>
To: Jim Nelson <james4765@cwazy.co.uk>
Cc: linuxppc-dev@ozlabs.org, Brian Gerst <bgerst@didntduck.org>,
paulus@samba.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*
Date: Wed, 5 Jan 2005 10:26:59 +0100 [thread overview]
Message-ID: <20050105092659.GA27103@lst.de> (raw)
In-Reply-To: <41DB5476.9040103@cwazy.co.uk>
On Tue, Jan 04, 2005 at 09:44:06PM -0500, Jim Nelson wrote:
> Brian Gerst wrote:
>
> >James Nelson wrote:
> >
> >>This series of patches is to remove the last cli()/sti() function
> >>calls in arch/ppc.
> >>
> >>These are the only instances in active code that grep could find.
> >
> >
> >Are you sure none of these need real spinlocks instead of just
> >disabling interrupts?
> >
> >--
> > Brian Gerst
> >
> These are for single-processor systems, mostly evaluation boards and
> embedded processors. I coudn't find any reference to multiprocessor
> setups for the processors in question after a peruse of the code or a
> quick google on the boards in question.
think CONFIG_PREEMPT. In either case a spinlock becomes
lock_irq_disable in the !SMP, !PREEMPT case but it documents the
intention a whole lot better.
Also you're locking only in a single plpace which is a ***BIG*** warning
sign. At least look at the other users of the data structure, it's
extremly likely they'll need locking aswell.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Jim Nelson <james4765@cwazy.co.uk>
Cc: Brian Gerst <bgerst@didntduck.org>,
linuxppc-dev@ozlabs.org, paulus@samba.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*
Date: Wed, 5 Jan 2005 10:26:59 +0100 [thread overview]
Message-ID: <20050105092659.GA27103@lst.de> (raw)
In-Reply-To: <41DB5476.9040103@cwazy.co.uk>
On Tue, Jan 04, 2005 at 09:44:06PM -0500, Jim Nelson wrote:
> Brian Gerst wrote:
>
> >James Nelson wrote:
> >
> >>This series of patches is to remove the last cli()/sti() function
> >>calls in arch/ppc.
> >>
> >>These are the only instances in active code that grep could find.
> >
> >
> >Are you sure none of these need real spinlocks instead of just
> >disabling interrupts?
> >
> >--
> > Brian Gerst
> >
> These are for single-processor systems, mostly evaluation boards and
> embedded processors. I coudn't find any reference to multiprocessor
> setups for the processors in question after a peruse of the code or a
> quick google on the boards in question.
think CONFIG_PREEMPT. In either case a spinlock becomes
lock_irq_disable in the !SMP, !PREEMPT case but it documents the
intention a whole lot better.
Also you're locking only in a single plpace which is a ***BIG*** warning
sign. At least look at the other users of the data structure, it's
extremly likely they'll need locking aswell.
next prev parent reply other threads:[~2005-01-05 9:36 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-04 21:40 [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/* James Nelson
2005-01-04 21:40 ` [PATCH 1/7] ppc: remove cli()/sti() in arch/ppc/4xx_io/serial_sicc.c James Nelson
2005-01-04 21:40 ` [PATCH 2/7] ppc: remove cli()/sti() in arch/ppc/8xx_io/cs4218_tdm.c James Nelson
2005-01-04 21:40 ` [PATCH 3/7] ppc: remove cli()/sti() in arch/ppc/8xx_io/fec.c James Nelson
2005-01-04 21:40 ` [PATCH 4/7] ppc: remove cli()/sti() in arch/ppc/platforms/apus_setup.c James Nelson
2005-01-04 21:41 ` [PATCH 5/7] ppc: remove cli()/sti() in arch/ppc/platforms/pal4_setup.c James Nelson
2005-01-04 21:41 ` [PATCH 6/7] ppc: remove cli()/sti() in arch/ppc/syslib/m8xx_setup.c James Nelson
2005-01-04 21:41 ` [PATCH 7/7] ppc: remove cli()/sti() in arch/ppc/syslib/qspan_pci.c James Nelson
2005-01-05 2:19 ` [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/* Brian Gerst
2005-01-05 2:19 ` Brian Gerst
2005-01-05 2:44 ` Jim Nelson
2005-01-05 2:44 ` Jim Nelson
2005-01-05 9:26 ` Christoph Hellwig [this message]
2005-01-05 9:26 ` Christoph Hellwig
2005-01-05 11:19 ` Jim Nelson
2005-01-05 11:19 ` Jim Nelson
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