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authorTom Zanussi <zanussi@us.ibm.com>2006-01-08 01:02:29 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-08 20:13:50 -0800
commite6c08367b8fc6dce6dfd1106f53f6ef28215b313 (patch)
treefa5bb7071fdcd61d3296e5d0be224d864cb1d166 /fs/relayfs/relay.c
parent[PATCH] relayfs: add Documentation on relay files in other filesystems (diff)
downloadlinux-dev-e6c08367b8fc6dce6dfd1106f53f6ef28215b313.tar.xz
linux-dev-e6c08367b8fc6dce6dfd1106f53f6ef28215b313.zip
[PATCH] relayfs: add support for global relay buffers
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>
Diffstat (limited to '')
-rw-r--r--fs/relayfs/relay.c35
1 files changed, 25 insertions, 10 deletions
diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c
index b9bb56903272..2935a6ab8ffa 100644
--- a/fs/relayfs/relay.c
+++ b/fs/relayfs/relay.c
@@ -86,7 +86,8 @@ static void buf_unmapped_default_callback(struct rchan_buf *buf,
static struct dentry *create_buf_file_default_callback(const char *filename,
struct dentry *parent,
int mode,
- struct rchan_buf *buf)
+ struct rchan_buf *buf,
+ int *is_global)
{
return relayfs_create_file(filename, parent, mode,
&relayfs_file_operations, buf);
@@ -170,14 +171,16 @@ static inline void __relay_reset(struct rchan_buf *buf, unsigned int init)
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->buf[i])
- continue;
+ if (!chan->buf[i] || chan->buf[i] == prev)
+ break;
__relay_reset(chan->buf[i], 0);
+ prev = chan->buf[i];
}
}
@@ -188,18 +191,22 @@ void relay_reset(struct rchan *chan)
*/
static struct rchan_buf *relay_open_buf(struct rchan *chan,
const char *filename,
- struct dentry *parent)
+ struct dentry *parent,
+ int *is_global)
{
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);
+ buf, is_global);
if (!dentry) {
relay_destroy_buf(buf);
return NULL;
@@ -273,6 +280,7 @@ struct rchan *relay_open(const char *base_filename,
unsigned int i;
struct rchan *chan;
char *tmpname;
+ int is_global = 0;
if (!base_filename)
return NULL;
@@ -297,7 +305,8 @@ struct rchan *relay_open(const char *base_filename,
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;
@@ -311,6 +320,8 @@ free_bufs:
if (!chan->buf[i])
break;
relay_close_buf(chan->buf[i]);
+ if (is_global)
+ break;
}
kfree(tmpname);
@@ -420,14 +431,16 @@ void relay_destroy_channel(struct kref *kref)
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->buf[i])
- continue;
+ if (!chan->buf[i] || chan->buf[i] == prev)
+ break;
relay_close_buf(chan->buf[i]);
+ prev = chan->buf[i];
}
if (chan->last_toobig)
@@ -447,14 +460,16 @@ void relay_close(struct rchan *chan)
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->buf[i])
- continue;
+ if (!chan->buf[i] || chan->buf[i] == prev)
+ break;
relay_switch_subbuf(chan->buf[i], 0);
+ prev = chan->buf[i];
}
}