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Diffstat (limited to 'include/linux/relay.h')
-rw-r--r--include/linux/relay.h23
1 files changed, 16 insertions, 7 deletions
diff --git a/include/linux/relay.h b/include/linux/relay.h
index d7c8359693c6..ecbb34a382b8 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -19,6 +19,7 @@
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/kref.h>
+#include <linux/percpu.h>
/*
* Tracks changes to rchan/rchan_buf structs
@@ -63,7 +64,7 @@ struct rchan
struct kref kref; /* channel refcount */
void *private_data; /* for user-defined data */
size_t last_toobig; /* tried to log event > subbuf size */
- struct rchan_buf *buf[NR_CPUS]; /* per-cpu channel buffers */
+ struct rchan_buf ** __percpu buf; /* per-cpu channel buffers */
int is_global; /* One global buffer ? */
struct list_head list; /* for channel list */
struct dentry *parent; /* parent dentry passed to open */
@@ -204,7 +205,7 @@ static inline void relay_write(struct rchan *chan,
struct rchan_buf *buf;
local_irq_save(flags);
- buf = chan->buf[smp_processor_id()];
+ buf = *this_cpu_ptr(chan->buf);
if (unlikely(buf->offset + length > chan->subbuf_size))
length = relay_switch_subbuf(buf, length);
memcpy(buf->data + buf->offset, data, length);
@@ -230,12 +231,12 @@ static inline void __relay_write(struct rchan *chan,
{
struct rchan_buf *buf;
- buf = chan->buf[get_cpu()];
+ buf = *get_cpu_ptr(chan->buf);
if (unlikely(buf->offset + length > buf->chan->subbuf_size))
length = relay_switch_subbuf(buf, length);
memcpy(buf->data + buf->offset, data, length);
buf->offset += length;
- put_cpu();
+ put_cpu_ptr(chan->buf);
}
/**
@@ -251,17 +252,19 @@ static inline void __relay_write(struct rchan *chan,
*/
static inline void *relay_reserve(struct rchan *chan, size_t length)
{
- void *reserved;
- struct rchan_buf *buf = chan->buf[smp_processor_id()];
+ void *reserved = NULL;
+ struct rchan_buf *buf = *get_cpu_ptr(chan->buf);
if (unlikely(buf->offset + length > buf->chan->subbuf_size)) {
length = relay_switch_subbuf(buf, length);
if (!length)
- return NULL;
+ goto end;
}
reserved = buf->data + buf->offset;
buf->offset += length;
+end:
+ put_cpu_ptr(chan->buf);
return reserved;
}
@@ -285,5 +288,11 @@ static inline void subbuf_start_reserve(struct rchan_buf *buf,
*/
extern const struct file_operations relay_file_operations;
+#ifdef CONFIG_RELAY
+int relay_prepare_cpu(unsigned int cpu);
+#else
+#define relay_prepare_cpu NULL
+#endif
+
#endif /* _LINUX_RELAY_H */