Re: PATCH powerpc: Merge asm-ppc*/hardirq.h

On Tue, Sep 13, 2005 at 03:38:40PM -0500, Jon Loeliger wrote:

+#ifndef _ASM_POWERPC_HARDIRQ_H
+#define _ASM_POWERPC_HARDIRQ_H
+#ifdef __KERNEL__

the __KERNEL__ ifdefs is not needed.  <asm/hardirq.h> is only included
from <linux/hardirq.h> which doesn't have anything user-visible.

+
+#include <linux/config.h>

not needed.

+#include <linux/cache.h>
+
+#ifdef __powerpc64__
+#include <linux/preempt.h>
+#else
+#include <linux/smp_lock.h>
+#include <asm/irq.h>
+#endif

We shouldn't need either of these include blocks at all.

+
+/* The __last_jiffy_stamp field is needed to ensure that no decrementer
+ * interrupt is lost on SMP machines. Since on most CPUs it is in the same
+ * cache line as local_irq_count, it is cheap to access and is also used on UP
+ * for uniformity.
+ */
+typedef struct {
+	unsigned int __softirq_pending;	/* set_bit is used on this */
+	unsigned int __last_jiffy_stamp;
+} ____cacheline_aligned irq_cpustat_t;

I'd suggest just using a DECLARE_PER_CPU variable for last_jiffy_stamp.
In facct I plan to get rid of irq_cpustat_t completely at some point.