Re: [PATCH 04/20] x86/ticketlock: make large and small ticketversions of spin_lock the same

From: Srivatsa Vaddagiri
Date: Fri Nov 12 2010 - 07:20:09 EST


On Wed, Nov 03, 2010 at 10:59:45AM -0400, Jeremy Fitzhardinge wrote:
> Make the bulk of __ticket_spin_lock look identical for large and small
> number of cpus.

[snip]

> #if (NR_CPUS < 256)
> static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock)
> {
> - register union {
> - struct __raw_tickets tickets;
> - unsigned short slock;
> - } inc = { .slock = 1 << TICKET_SHIFT };
> + register struct __raw_tickets inc = { .tail = 1 };

[snip]

> #else
> static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock)
> {
> - unsigned inc = 1 << TICKET_SHIFT;
> - __ticket_t tmp;
> + register struct __raw_tickets inc = { .tickets.tail = 1 };

s/.tickets//?

Otherwise I get a compile error for NR_CPUS > 256, with just 4 patches applied.

- vatsa
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