Pekka Paalanen a écrit :
On Tue, 05 Feb 2008 21:44:07 +0100
Eric Dumazet <[EMAIL PROTECTED]> wrote:
Pekka Paalanen a écrit :
diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c
b/arch/x86/kernel/mmiotrace/mmio-mod.c
index 82ae920..f492b65 100644
--- a/arch/x86/kernel/mmiotrace/mmio-mod.c
+++ b/arch/x86/kernel/mmiotrace/mmio-mod.c
@@ -47,9 +48,13 @@ struct trap_reason {
int active_traces;
};
+/* Accessed per-cpu. */
static struct trap_reason pf_reason[NR_CPUS];
static struct mm_io_header_rw cpu_trace[NR_CPUS];
+/* Access to this is not per-cpu. */
+static atomic_t dropped[NR_CPUS];
+
Please dont introduce NR_CPUS new arrays, since people are working hard to zap
them from kernel.
You probably can use a per_cpu variable ?
Yes, it would probably be more appropriate to use DEFINE_PER_CPU()
for 'pf_reason' and 'cpu_trace', but I wasn't sure since the examples
of DEFINE_PER_CPU I saw always had integers or pointers, not
whole structs. Is it okay for whole structs?
yes you can use a structure, you can check for example :
net/ipv4/route.c:static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
'dropped' on the other hand is not accessed in per-cpu style, any cpu
may access any element. DEFINE_PER_CPU is not valid here, is it?
It is valid, you can use per_cpu() accessor to get a pointer to a particular
cpu data.
check net/ipv4/route.c for an example :
return &per_cpu(rt_cache_stat, cpu);
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