On 16/03/2015 06:31, Fam Zheng wrote:
> The caller's workflow is like
>
> if (!address_space_map()) {
> ...
> cpu_register_map_client();
> }
>
> If bounce buffer became available after address_space_map() but before
> cpu_register_map_client(), the caller could miss it and has to wait for the
> next bounce buffer notify, which may never happen in the worse case.
>
> Just notify the list in cpu_register_map_client().
>
> Signed-off-by: Fam Zheng <f...@redhat.com>
> ---
> exec.c | 22 +++++++++++++++-------
> 1 file changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 3e54580..20381a0 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2489,6 +2489,17 @@ QemuMutex map_client_list_lock;
> static QLIST_HEAD(map_client_list, MapClient) map_client_list
> = QLIST_HEAD_INITIALIZER(map_client_list);
>
> +static void cpu_notify_map_clients_unlocked(void)
> +{
> + MapClient *client;
> +
> + while (!QLIST_EMPTY(&map_client_list)) {
> + client = QLIST_FIRST(&map_client_list);
> + client->callback(client->opaque);
> + cpu_unregister_map_client(client);
> + }
> +}
Isn't the convention to call these functions "*_locked" (e.g.
timer_mod_ns_locked, monitor_flush_locked, cpu_get_clock_locked)?
Otherwise okay.
Paolo
> +
> void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque))
> {
> MapClient *client = g_malloc(sizeof(*client));
> @@ -2497,6 +2508,9 @@ void *cpu_register_map_client(void *opaque, void
> (*callback)(void *opaque))
> client->opaque = opaque;
> client->callback = callback;
> QLIST_INSERT_HEAD(&map_client_list, client, link);
> + if (!atomic_read(&bounce.in_use)) {
> + cpu_notify_map_clients_unlocked();
> + }
> qemu_mutex_unlock(&map_client_list_lock);
> return client;
> }
> @@ -2521,14 +2535,8 @@ static void cpu_unregister_map_client(void *_client)
>
> static void cpu_notify_map_clients(void)
> {
> - MapClient *client;
> -
> qemu_mutex_lock(&map_client_list_lock);
> - while (!QLIST_EMPTY(&map_client_list)) {
> - client = QLIST_FIRST(&map_client_list);
> - client->callback(client->opaque);
> - cpu_unregister_map_client(client);
> - }
> + cpu_notify_map_clients_unlocked();
> qemu_mutex_unlock(&map_client_list_lock);
> }
>
>
