* Re: per_cpu data question
[not found] <20020829182431.A4936@in.ibm.com>
@ 2002-08-30 1:59 ` Rusty Russell
0 siblings, 0 replies; only message in thread
From: Rusty Russell @ 2002-08-30 1:59 UTC (permalink / raw)
To: dipankar; +Cc: trivial, torvalds, linux-kernel
In message <20020829182431.A4936@in.ibm.com> you write:
> Hi Rusty,
>
> I can't do this -
>
> struct rcu_data *rdata;
> rdata = &get_cpu_var(rcu_data);
>
> Has this been deliberately made illegal ?
No, I suck. Lvalues continue to haunt me. This works for me.
BTW, I prefer to have bug reports cc'd to linux-kernel, so the
results are archived. Plus, public humiliation is good for the
soul.
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.32/include/linux/percpu.h working-2.5.32-percpu/include/linux/percpu.h
--- linux-2.5.32/include/linux/percpu.h 2002-08-28 09:29:53.000000000 +1000
+++ working-2.5.32-percpu/include/linux/percpu.h 2002-08-30 11:50:46.000000000 +1000
@@ -3,7 +3,8 @@
#include <linux/spinlock.h> /* For preempt_disable() */
#include <asm/percpu.h>
-#define get_cpu_var(var) ({ preempt_disable(); __get_cpu_var(var); })
+/* Must be an lvalue. */
+#define get_cpu_var(var) (*({ preempt_disable(); &__get_cpu_var(var); }))
#define put_cpu_var(var) preempt_enable()
#endif /* __LINUX_PERCPU_H */
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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