This patch adds the optional is_global outparam to the create_buf_file()
callback. This can be used by clients to create a single global relayfs
buffer instead of the default per-cpu buffers. This was suggested as being
useful for certain debugging applications where it's more convenient to be
able to get all the data from a single channel without having to go to the
bother of dealing with per-cpu files.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
static struct dentry *create_buf_file_default_callback(const char *filename,
struct dentry *parent,
int mode,
static struct dentry *create_buf_file_default_callback(const char *filename,
struct dentry *parent,
int mode,
+ struct rchan_buf *buf,
+ int *is_global)
{
return relayfs_create_file(filename, parent, mode,
&relayfs_file_operations, buf);
{
return relayfs_create_file(filename, parent, mode,
&relayfs_file_operations, buf);
void relay_reset(struct rchan *chan)
{
unsigned int i;
void relay_reset(struct rchan *chan)
{
unsigned int i;
+ struct rchan_buf *prev = NULL;
if (!chan)
return;
for (i = 0; i < NR_CPUS; i++) {
if (!chan)
return;
for (i = 0; i < NR_CPUS; i++) {
- if (!chan->buf[i])
- continue;
+ if (!chan->buf[i] || chan->buf[i] == prev)
+ break;
__relay_reset(chan->buf[i], 0);
__relay_reset(chan->buf[i], 0);
*/
static struct rchan_buf *relay_open_buf(struct rchan *chan,
const char *filename,
*/
static struct rchan_buf *relay_open_buf(struct rchan *chan,
const char *filename,
+ struct dentry *parent,
+ int *is_global)
{
struct rchan_buf *buf;
struct dentry *dentry;
{
struct rchan_buf *buf;
struct dentry *dentry;
+ if (*is_global)
+ return chan->buf[0];
+
buf = relay_create_buf(chan);
if (!buf)
return NULL;
/* Create file in fs */
dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR,
buf = relay_create_buf(chan);
if (!buf)
return NULL;
/* Create file in fs */
dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR,
if (!dentry) {
relay_destroy_buf(buf);
return NULL;
if (!dentry) {
relay_destroy_buf(buf);
return NULL;
unsigned int i;
struct rchan *chan;
char *tmpname;
unsigned int i;
struct rchan *chan;
char *tmpname;
if (!base_filename)
return NULL;
if (!base_filename)
return NULL;
for_each_online_cpu(i) {
sprintf(tmpname, "%s%d", base_filename, i);
for_each_online_cpu(i) {
sprintf(tmpname, "%s%d", base_filename, i);
- chan->buf[i] = relay_open_buf(chan, tmpname, parent);
+ chan->buf[i] = relay_open_buf(chan, tmpname, parent,
+ &is_global);
chan->buf[i]->cpu = i;
if (!chan->buf[i])
goto free_bufs;
chan->buf[i]->cpu = i;
if (!chan->buf[i])
goto free_bufs;
if (!chan->buf[i])
break;
relay_close_buf(chan->buf[i]);
if (!chan->buf[i])
break;
relay_close_buf(chan->buf[i]);
+ if (is_global)
+ break;
void relay_close(struct rchan *chan)
{
unsigned int i;
void relay_close(struct rchan *chan)
{
unsigned int i;
+ struct rchan_buf *prev = NULL;
if (!chan)
return;
for (i = 0; i < NR_CPUS; i++) {
if (!chan)
return;
for (i = 0; i < NR_CPUS; i++) {
- if (!chan->buf[i])
- continue;
+ if (!chan->buf[i] || chan->buf[i] == prev)
+ break;
relay_close_buf(chan->buf[i]);
relay_close_buf(chan->buf[i]);
void relay_flush(struct rchan *chan)
{
unsigned int i;
void relay_flush(struct rchan *chan)
{
unsigned int i;
+ struct rchan_buf *prev = NULL;
if (!chan)
return;
for (i = 0; i < NR_CPUS; i++) {
if (!chan)
return;
for (i = 0; i < NR_CPUS; i++) {
- if (!chan->buf[i])
- continue;
+ if (!chan->buf[i] || chan->buf[i] == prev)
+ break;
relay_switch_subbuf(chan->buf[i], 0);
relay_switch_subbuf(chan->buf[i], 0);
* @parent: the parent of the file to create
* @mode: the mode of the file to create
* @buf: the channel buffer
* @parent: the parent of the file to create
* @mode: the mode of the file to create
* @buf: the channel buffer
+ * @is_global: outparam - set non-zero if the buffer should be global
*
* Called during relay_open(), once for each per-cpu buffer,
* to allow the client to create a file to be used to
*
* Called during relay_open(), once for each per-cpu buffer,
* to allow the client to create a file to be used to
* The callback should return the dentry of the file created
* to represent the relay buffer.
*
* The callback should return the dentry of the file created
* to represent the relay buffer.
*
+ * Setting the is_global outparam to a non-zero value will
+ * cause relay_open() to create a single global buffer rather
+ * than the default set of per-cpu buffers.
+ *
* See Documentation/filesystems/relayfs.txt for more info.
*/
struct dentry *(*create_buf_file)(const char *filename,
struct dentry *parent,
int mode,
* See Documentation/filesystems/relayfs.txt for more info.
*/
struct dentry *(*create_buf_file)(const char *filename,
struct dentry *parent,
int mode,
- struct rchan_buf *buf);
+ struct rchan_buf *buf,
+ int *is_global);
/*
* remove_buf_file - remove file representing a relayfs channel buffer
/*
* remove_buf_file - remove file representing a relayfs channel buffer