----- Original Message -----
> From: "Geneviève Bastien" <[email protected]>
> To: [email protected]
> Sent: Friday, January 24, 2014 3:07:25 PM
> Subject: [lttng-dev] [Patch LTTng-tools 4/4] Dump a named metadata only once  
> per session
> 
> Named metadata can be used more than once in a single tracepoint, or many

(global types ?)

This is adding a linked-list (O(n)) on something that can be called
quite often. It will not scale if there are many enums in a process.
This should be changed into a hash table.


> tracepoints can use it. It must be statedumped only once in a given session.
> 
> Signed-off-by: Geneviève Bastien <[email protected]>
> ---
>  src/bin/lttng-sessiond/ust-metadata.c | 39
>  +++++++++++++++++++++++++++++++++++
>  src/bin/lttng-sessiond/ust-registry.c | 11 ++++++++++
>  src/bin/lttng-sessiond/ust-registry.h |  8 +++++++
>  3 files changed, 58 insertions(+)
> 
> diff --git a/src/bin/lttng-sessiond/ust-metadata.c
> b/src/bin/lttng-sessiond/ust-metadata.c
> index 87d21fc..8b904a8 100644
> --- a/src/bin/lttng-sessiond/ust-metadata.c
> +++ b/src/bin/lttng-sessiond/ust-metadata.c
> @@ -316,6 +316,27 @@ int _lttng_one_metadata_statedump(struct
> ust_registry_session *session,
>  {
>       int ret = 0, i;
>  
> +     /* Check if the metadata was already dumped */
> +     if (session->dumped_named_metadata != 0) {
> +             struct ust_dumped_metadata *dumped = 
> session->dumped_named_metadata;
> +             char *metadata_name;

missing newline.

Thanks,

Mathieu

> +             switch (metadata->mtype) {
> +             case ustctl_mtype_enum:
> +                     metadata_name = metadata->u.ctf_enum.name;
> +                     break;
> +             default:
> +                     return -EINVAL;
> +             }
> +             do {
> +                     if (dumped->mtype == metadata->mtype) {
> +                             if (strcmp(dumped->name, metadata_name) == 0) {
> +                                     return 0;
> +                             }
> +                     }
> +                     dumped = dumped->next;
> +             } while (dumped);
> +     }
> +
>       switch (metadata->mtype) {
>       case ustctl_mtype_enum:
>       {
> @@ -362,6 +383,24 @@ int _lttng_one_metadata_statedump(struct
> ust_registry_session *session,
>               return -EINVAL;
>       }
>  
> +     /* Flag this metadata as dumped */
> +     struct ust_dumped_metadata *dumped;
> +     dumped = zmalloc(sizeof(*dumped));
> +     if (!dumped) {
> +             ret = -ENOMEM;
> +             return ret;
> +     }
> +     dumped->mtype = metadata->mtype;
> +     switch (metadata->mtype) {
> +     case ustctl_mtype_enum:
> +             strncpy(dumped->name, metadata->u.ctf_enum.name, 
> LTTNG_UST_SYM_NAME_LEN);
> +             break;
> +     default:
> +             return -EINVAL;
> +     }
> +     dumped->next = session->dumped_named_metadata;
> +     session->dumped_named_metadata = dumped;
> +
>       return ret;
>  }
>  
> diff --git a/src/bin/lttng-sessiond/ust-registry.c
> b/src/bin/lttng-sessiond/ust-registry.c
> index 00e1c26..25cd31d 100644
> --- a/src/bin/lttng-sessiond/ust-registry.c
> +++ b/src/bin/lttng-sessiond/ust-registry.c
> @@ -568,6 +568,7 @@ int ust_registry_session_init(struct ust_registry_session
> **sessionp,
>       session->uint64_t_alignment = uint64_t_alignment;
>       session->long_alignment = long_alignment;
>       session->byte_order = byte_order;
> +     session->dumped_named_metadata = 0;
>  
>       session->channels = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
>       if (!session->channels) {
> @@ -630,4 +631,14 @@ void ust_registry_session_destroy(struct
> ust_registry_session *reg)
>       }
>  
>       free(reg->metadata);
> +
> +     /* Free all dumped metadata */
> +     if (reg->dumped_named_metadata) {
> +             struct ust_dumped_metadata *dumped;
> +             do {
> +                     dumped = reg->dumped_named_metadata;
> +                     reg->dumped_named_metadata = dumped->next;
> +                     free(dumped);
> +             } while (reg->dumped_named_metadata);
> +     }
>  }
> diff --git a/src/bin/lttng-sessiond/ust-registry.h
> b/src/bin/lttng-sessiond/ust-registry.h
> index 183db0f..a6c7e6e 100644
> --- a/src/bin/lttng-sessiond/ust-registry.h
> +++ b/src/bin/lttng-sessiond/ust-registry.h
> @@ -31,6 +31,12 @@
>  
>  struct ust_app;
>  
> +struct ust_dumped_metadata {
> +     enum ustctl_metadata_types mtype;
> +     char name[LTTNG_UST_SYM_NAME_LEN];
> +     struct ust_dumped_metadata *next;
> +};
> +
>  struct ust_registry_session {
>       /*
>        * With multiple writers and readers, use this lock to access the 
> registry.
> @@ -75,6 +81,8 @@ struct ust_registry_session {
>        * deletes its sessions.
>        */
>       unsigned int metadata_closed;
> +     /* The list of named metadata already dumped */
> +     struct ust_dumped_metadata *dumped_named_metadata;
>  };
>  
>  struct ust_registry_channel {
> --
> 1.8.5.3
> 
> 
> _______________________________________________
> lttng-dev mailing list
> [email protected]
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
> 

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

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