Fix: don't perform extra flush on metadata channel

[lttng-modules.git] / lttng-events.c

diff --git a/lttng-events.c b/lttng-events.c
index 9b3d766915fd4dcd78f564b1681497eccccf5b26..c129767469db48ebc3880496a0bf2fa0e7249dea 100644 (file)
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -34,6 +34,8 @@
 #include <linux/jiffies.h>
 #include <linux/utsname.h>
 #include <linux/err.h>
+#include <linux/vmalloc.h>
+
 #include "wrapper/uuid.h"
 #include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "wrapper/random.h"
@@ -42,6 +44,9 @@
 #include "lttng-events.h"
 #include "lttng-tracer.h"
 #include "lttng-abi-old.h"
+#include "wrapper/vzalloc.h"
+#include "wrapper/ringbuffer/backend.h"
+#include "wrapper/ringbuffer/frontend.h"
 
 #define METADATA_CACHE_DEFAULT_SIZE 4096
 
@@ -96,8 +101,7 @@ struct lttng_session *lttng_session_create(void)
                        GFP_KERNEL);
        if (!metadata_cache)
                goto err_free_session;
-       metadata_cache->data = kzalloc(METADATA_CACHE_DEFAULT_SIZE,
-                       GFP_KERNEL);
+       metadata_cache->data = lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE);
        if (!metadata_cache->data)
                goto err_free_cache;
        metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
@@ -124,7 +128,7 @@ void metadata_cache_destroy(struct kref *kref)
 {
        struct lttng_metadata_cache *cache =
                container_of(kref, struct lttng_metadata_cache, refcount);
-       kfree(cache->data);
+       vfree(cache->data);
        kfree(cache);
 }
 
@@ -184,6 +188,10 @@ int lttng_session_enable(struct lttng_session *session)
                        chan->header_type = 2;  /* large */
        }
 
+       /* Clear each stream's quiescent state. */
+       list_for_each_entry(chan, &session->chan, list)
+               lib_ring_buffer_clear_quiescent_channel(chan->chan);
+
        ACCESS_ONCE(session->active) = 1;
        ACCESS_ONCE(session->been_active) = 1;
        ret = _lttng_session_metadata_statedump(session);
@@ -202,6 +210,7 @@ end:
 int lttng_session_disable(struct lttng_session *session)
 {
        int ret = 0;
+       struct lttng_channel *chan;
 
        mutex_lock(&sessions_mutex);
        if (!session->active) {
@@ -209,6 +218,11 @@ int lttng_session_disable(struct lttng_session *session)
                goto end;
        }
        ACCESS_ONCE(session->active) = 0;
+
+       /* Set each stream's quiescent state. */
+       list_for_each_entry(chan, &session->chan, list)
+               lib_ring_buffer_set_quiescent_channel(chan->chan);
+
 end:
        mutex_unlock(&sessions_mutex);
        return ret;
@@ -687,10 +701,16 @@ int lttng_metadata_printf(struct lttng_session *session,
                tmp_cache_alloc_size = max_t(unsigned int,
                                session->metadata_cache->cache_alloc + len,
                                session->metadata_cache->cache_alloc << 1);
-               tmp_cache_realloc = krealloc(session->metadata_cache->data,
-                               tmp_cache_alloc_size, GFP_KERNEL);
+               tmp_cache_realloc = lttng_vzalloc(tmp_cache_alloc_size);
                if (!tmp_cache_realloc)
                        goto err;
+               if (session->metadata_cache->data) {
+                       memcpy(tmp_cache_realloc,
+                               session->metadata_cache->data,
+                               session->metadata_cache->cache_alloc);
+                       vfree(session->metadata_cache->data);
+               }
+
                session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
                session->metadata_cache->data = tmp_cache_realloc;
        }