4 messages, 3 authors, 2005-01-05 · open the first message on its own page
From: Brian Gerst <hidden>
Date: 2005-01-05 02:19:23
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
From: Jim Nelson <hidden>
Date: 2005-01-05 02:43:58
Brian Gerst wrote:
James Nelson wrote:quoted
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. Jim
From: Christoph Hellwig <hch@lst.de>
Date: 2005-01-05 09:27:31
On Tue, Jan 04, 2005 at 09:44:06PM -0500, Jim Nelson wrote:
Brian Gerst wrote:quoted
James Nelson wrote:quoted
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 GerstThese 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.
From: Jim Nelson <hidden>
Date: 2005-01-05 11:19:21
Christoph Hellwig wrote:
On Tue, Jan 04, 2005 at 09:44:06PM -0500, Jim Nelson wrote:quoted
Brian Gerst wrote:quoted
James Nelson wrote:quoted
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 GerstThese 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.
Some of the cli() uses were in shutdown and IRQ setup code, where you'd just need to disable interrupts. There are a few files that will need a more thourough going-through, however. I'll start checking those later. Jim