Hi Jiayu,
On 9/18/2017 9:49 PM, Jiayu Hu wrote:
Hi Jianfeng,
On Fri, Aug 25, 2017 at 09:40:46AM +0000, Jianfeng Tan wrote:
Previouly, there is only one way for primary/secondary to exchange
messages, that is, primary process writes info into some predefind
file, and secondary process reads info out. That cannot address
the requirements:
a. Secondary wants to send info to primary.
b. Sending info at any time, instead of just initialization time.
c. Share FD with the other side.
If you can explain more about why the above three characters are required
for enabling vdev in the secondary process here, that would be better. For
example, vdev may hot plugin or remove, so the primary and the secondary
process need to exchange data bidirectionally and dynamically.
OK, I'll exemplify each item with a case.
This patch proposes to create a communication channel (as an unix
socket connection) for above requirements.
Can you give more explainations about how the channel works? Like both
the primary and the secondary register actions for specific messages, and
another thread is created to listen and react incoming messages.
I suppose for users/developers who want to use it, below description
about how to use related APIs is enough. As for how the channel is
created, i'll try to describe more here.
Three new APIs are added:
1. rte_eal_primary_secondary_add_action is used to register an action,
if the calling component wants to response the messages from the
corresponding component in its primary process or secondary processes.
2. rte_eal_primary_secondary_del_action is used to unregister the
action if the calling component does not want to response the messages.
3. rte_eal_primary_secondary_sendmsg is used to send a message.
Signed-off-by: Jianfeng Tan <jianfeng....@intel.com>
---
lib/librte_eal/bsdapp/eal/rte_eal_version.map | 8 +
lib/librte_eal/common/eal_common_proc.c | 454 ++++++++++++++++++++++++
lib/librte_eal/common/eal_filesystem.h | 18 +
lib/librte_eal/common/eal_private.h | 10 +
lib/librte_eal/common/include/rte_eal.h | 74 ++++
lib/librte_eal/linuxapp/eal/eal.c | 6 +
lib/librte_eal/linuxapp/eal/rte_eal_version.map | 8 +
7 files changed, 578 insertions(+)
...
+
+int
+rte_eal_primary_secondary_add_action(const char *action_name,
+ rte_eal_primary_secondary_t action)
+{
+ struct action_entry *entry = malloc(sizeof(struct action_entry));
+
+ if (entry == NULL)
+ return -ENOMEM;
+
+ strncpy(entry->action_name, action_name, MAX_ACTION_NAME_LEN);
+ entry->action = action;
In struct action_entry, the type of action is 'rte_eal_primary_secondary_t *',
but you assign an object to action here.
Nice catch!
+ TAILQ_INSERT_TAIL(&action_entry_list, entry, next);
What would happen if register two actions for a same message name?
Hmm, yes, let's return error if there's an existing one for that name.
+ return 0;
+}
+
+void
+rte_eal_primary_secondary_del_action(const char *name)
+{
+ struct action_entry *entry = find_action_entry_by_name(name);
+
+ TAILQ_REMOVE(&action_entry_list, entry, next);
+ free(entry);
+}
+
+#define MAX_SECONDARY_PROCS 8
A simple question: why the max number is 8?
Just a hard-coded value.
Thanks,
Jianfeng
