[Qemu-devel] [PATCH 3/9] event poll: make epoll work for normal fd

2013-02-21 Thread Liu Ping Fan 
From: Liu Ping Fan pingf...@linux.vnet.ibm.com

When event poll can work with normal fd, we can port them
onto the event loop.

Signed-off-by: Liu Ping Fan pingf...@linux.vnet.ibm.com
---
 hw/dataplane/event-poll.c |   36 
 hw/dataplane/event-poll.h |8 
 2 files changed, 44 insertions(+), 0 deletions(-)

diff --git a/hw/dataplane/event-poll.c b/hw/dataplane/event-poll.c
index 2b55c6e..b7dea53 100644
--- a/hw/dataplane/event-poll.c
+++ b/hw/dataplane/event-poll.c
@@ -32,6 +32,42 @@ void event_poll_add(EventPoll *poll, EventHandler *handler,
 }
 }
 
+void event_poll_add_fd(EventPoll *poll, int fd, uint32_t type,
+EventHandler *handler)
+{
+struct epoll_event event = {
+.events = type,
+.data.ptr = handler,
+};
+
+if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_ADD, fd, event) != 0) {
+fprintf(stderr, failed to add event fd handler to epoll: %m\n);
+exit(1);
+}
+
+}
+void event_poll_del_fd(EventPoll *poll, int fd)
+{
+if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_DEL, fd, NULL) != 0) {
+fprintf(stderr, failed to del event handler to epoll: %m\n);
+exit(1);
+}
+}
+
+
+void event_poll_modify_fd(EventPoll *poll, int fd, uint32_t type,
+EventHandler *handler)
+{
+struct epoll_event event = {
+.events = type,
+.data.ptr = handler,
+};
+if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_MOD, fd, event) != 0) {
+fprintf(stderr, failed to modify event handler to epoll: %m\n);
+exit(1);
+}
+}
+
 /* Event callback for stopping event_poll() */
 static void handle_stop(EventHandler *handler)
 {
diff --git a/hw/dataplane/event-poll.h b/hw/dataplane/event-poll.h
index 3e8d3ec..606138c 100644
--- a/hw/dataplane/event-poll.h
+++ b/hw/dataplane/event-poll.h
@@ -22,6 +22,8 @@ typedef void EventCallback(EventHandler *handler);
 struct EventHandler {
 EventNotifier *notifier;/* eventfd */
 EventCallback *callback;/* callback function */
+void *opaque;
+int fd; /* normal fd*/
 };
 
 typedef struct {
@@ -32,6 +34,12 @@ typedef struct {
 
 void event_poll_add(EventPoll *poll, EventHandler *handler,
 EventNotifier *notifier, EventCallback *callback);
+void event_poll_add_fd(EventPoll *poll, int fd, uint32_t type,
+EventHandler *handler);
+void event_poll_del_fd(EventPoll *poll, int fd);
+void event_poll_modify_fd(EventPoll *poll, int fd, uint32_t type,
+EventHandler *handler);
+
 void event_poll_init(EventPoll *poll);
 void event_poll_cleanup(EventPoll *poll);
 void event_poll(EventPoll *poll);
-- 
1.7.4.4

Re: [Qemu-devel] [PATCH 3/9] event poll: make epoll work for normal fd

2013-02-21 Thread Paolo Bonzini 
Il 21/02/2013 13:54, Liu Ping Fan ha scritto:
 From: Liu Ping Fan pingf...@linux.vnet.ibm.com
 
 When event poll can work with normal fd, we can port them
 onto the event loop.

Please start transitioning to the AioContext API instead.  I doubt there
is any performance difference for 2-3 file descriptors between poll and
epoll, but if there were any we can introduce aio-linux.c that uses epoll.

I'll send later a patch to use AioContext instead of EventPoll for
virtio-blk dataplane.

Paolo

 Signed-off-by: Liu Ping Fan pingf...@linux.vnet.ibm.com
 ---
  hw/dataplane/event-poll.c |   36 
  hw/dataplane/event-poll.h |8 
  2 files changed, 44 insertions(+), 0 deletions(-)
 
 diff --git a/hw/dataplane/event-poll.c b/hw/dataplane/event-poll.c
 index 2b55c6e..b7dea53 100644
 --- a/hw/dataplane/event-poll.c
 +++ b/hw/dataplane/event-poll.c
 @@ -32,6 +32,42 @@ void event_poll_add(EventPoll *poll, EventHandler *handler,
  }
  }
  
 +void event_poll_add_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler)
 +{
 +struct epoll_event event = {
 +.events = type,
 +.data.ptr = handler,
 +};
 +
 +if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_ADD, fd, event) != 0) {
 +fprintf(stderr, failed to add event fd handler to epoll: %m\n);
 +exit(1);
 +}
 +
 +}
 +void event_poll_del_fd(EventPoll *poll, int fd)
 +{
 +if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_DEL, fd, NULL) != 0) {
 +fprintf(stderr, failed to del event handler to epoll: %m\n);
 +exit(1);
 +}
 +}
 +
 +
 +void event_poll_modify_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler)
 +{
 +struct epoll_event event = {
 +.events = type,
 +.data.ptr = handler,
 +};
 +if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_MOD, fd, event) != 0) {
 +fprintf(stderr, failed to modify event handler to epoll: %m\n);
 +exit(1);
 +}
 +}
 +
  /* Event callback for stopping event_poll() */
  static void handle_stop(EventHandler *handler)
  {
 diff --git a/hw/dataplane/event-poll.h b/hw/dataplane/event-poll.h
 index 3e8d3ec..606138c 100644
 --- a/hw/dataplane/event-poll.h
 +++ b/hw/dataplane/event-poll.h
 @@ -22,6 +22,8 @@ typedef void EventCallback(EventHandler *handler);
  struct EventHandler {
  EventNotifier *notifier;/* eventfd */
  EventCallback *callback;/* callback function */
 +void *opaque;
 +int fd; /* normal fd*/
  };
  
  typedef struct {
 @@ -32,6 +34,12 @@ typedef struct {
  
  void event_poll_add(EventPoll *poll, EventHandler *handler,
  EventNotifier *notifier, EventCallback *callback);
 +void event_poll_add_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler);
 +void event_poll_del_fd(EventPoll *poll, int fd);
 +void event_poll_modify_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler);
 +
  void event_poll_init(EventPoll *poll);
  void event_poll_cleanup(EventPoll *poll);
  void event_poll(EventPoll *poll);

Re: [Qemu-devel] [PATCH 3/9] event poll: make epoll work for normal fd

2013-02-21 Thread Stefan Hajnoczi 
On Thu, Feb 21, 2013 at 02:24:21PM +0100, Paolo Bonzini wrote:
 Il 21/02/2013 13:54, Liu Ping Fan ha scritto:
  From: Liu Ping Fan pingf...@linux.vnet.ibm.com
  
  When event poll can work with normal fd, we can port them
  onto the event loop.
 
 Please start transitioning to the AioContext API instead.  I doubt there
 is any performance difference for 2-3 file descriptors between poll and
 epoll, but if there were any we can introduce aio-linux.c that uses epoll.
 
 I'll send later a patch to use AioContext instead of EventPoll for
 virtio-blk dataplane.

Thanks Paolo.  Although using AioContext for dataplane's event loop has
been on my TODO list I haven't written any code yet - so no duplicated
work if you have time to tackle this.

Stefan

Re: [Qemu-devel] [PATCH 3/9] event poll: make epoll work for normal fd

2013-02-21 Thread mdroth 
On Thu, Feb 21, 2013 at 08:54:47PM +0800, Liu Ping Fan wrote:
 From: Liu Ping Fan pingf...@linux.vnet.ibm.com
 
 When event poll can work with normal fd, we can port them
 onto the event loop.
 
 Signed-off-by: Liu Ping Fan pingf...@linux.vnet.ibm.com
 ---
  hw/dataplane/event-poll.c |   36 
  hw/dataplane/event-poll.h |8 
  2 files changed, 44 insertions(+), 0 deletions(-)
 
 diff --git a/hw/dataplane/event-poll.c b/hw/dataplane/event-poll.c
 index 2b55c6e..b7dea53 100644
 --- a/hw/dataplane/event-poll.c
 +++ b/hw/dataplane/event-poll.c
 @@ -32,6 +32,42 @@ void event_poll_add(EventPoll *poll, EventHandler *handler,
  }
  }
 
 +void event_poll_add_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler)
 +{
 +struct epoll_event event = {
 +.events = type,
 +.data.ptr = handler,
 +};
 +
 +if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_ADD, fd, event) != 0) {
 +fprintf(stderr, failed to add event fd handler to epoll: %m\n);
 +exit(1);
 +}
 +
 +}

An alternative to adding these interfaces would be initializing an
EventNotifier using event_notifier_init_fd() and then passing that in to
event_poll_add()

I think doing it this way would be applicable on top of Paolo's
patches to switch dataplane to using AioContext as well.

 +void event_poll_del_fd(EventPoll *poll, int fd)
 +{
 +if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_DEL, fd, NULL) != 0) {
 +fprintf(stderr, failed to del event handler to epoll: %m\n);
 +exit(1);
 +}
 +}
 +
 +
 +void event_poll_modify_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler)
 +{
 +struct epoll_event event = {
 +.events = type,
 +.data.ptr = handler,
 +};
 +if (epoll_ctl(poll-epoll_fd, EPOLL_CTL_MOD, fd, event) != 0) {
 +fprintf(stderr, failed to modify event handler to epoll: %m\n);
 +exit(1);
 +}
 +}
 +
  /* Event callback for stopping event_poll() */
  static void handle_stop(EventHandler *handler)
  {
 diff --git a/hw/dataplane/event-poll.h b/hw/dataplane/event-poll.h
 index 3e8d3ec..606138c 100644
 --- a/hw/dataplane/event-poll.h
 +++ b/hw/dataplane/event-poll.h
 @@ -22,6 +22,8 @@ typedef void EventCallback(EventHandler *handler);
  struct EventHandler {
  EventNotifier *notifier;/* eventfd */
  EventCallback *callback;/* callback function */
 +void *opaque;
 +int fd; /* normal fd*/
  };
 
  typedef struct {
 @@ -32,6 +34,12 @@ typedef struct {
 
  void event_poll_add(EventPoll *poll, EventHandler *handler,
  EventNotifier *notifier, EventCallback *callback);
 +void event_poll_add_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler);
 +void event_poll_del_fd(EventPoll *poll, int fd);
 +void event_poll_modify_fd(EventPoll *poll, int fd, uint32_t type,
 +EventHandler *handler);
 +
  void event_poll_init(EventPoll *poll);
  void event_poll_cleanup(EventPoll *poll);
  void event_poll(EventPoll *poll);
 -- 
 1.7.4.4