[Qemu-devel] [RFC PATCH V7 5/7] qemu-char: Fix context for g_source_attach()

[Qemu-devel] [RFC PATCH V7 5/7] qemu-char: Fix context for g_source_attach()

[Zhang Chen]

We want to poll and handle chardev in another thread
other than main loop. But qemu_chr_add_handlers() can only
work for global default context other than thread default context.
So we use g_source_attach(xx, g_main_context_get_thread_default())
replace g_source_attach(xx, NULL) to attach g_source.
Comments from jason.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 io/channel.c | 2 +-
 qemu-char.c  | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/io/channel.c b/io/channel.c
index 692eb17..cd25677 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -146,7 +146,7 @@ guint qio_channel_add_watch(QIOChannel *ioc,
 
     g_source_set_callback(source, (GSourceFunc)func, user_data, notify);
 
-    id = g_source_attach(source, NULL);
+    id = g_source_attach(source, g_main_context_get_thread_default());
     g_source_unref(source);
 
     return id;
diff --git a/qemu-char.c b/qemu-char.c
index b597ee1..ed7e1f7 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -860,7 +860,7 @@ static gboolean io_watch_poll_prepare(GSource *source, gint *timeout_)
         iwp->src = qio_channel_create_watch(
             iwp->ioc, G_IO_IN | G_IO_ERR | G_IO_HUP | G_IO_NVAL);
         g_source_set_callback(iwp->src, iwp->fd_read, iwp->opaque, NULL);
-        g_source_attach(iwp->src, NULL);
+        g_source_attach(iwp->src, g_main_context_get_thread_default());
     } else {
         g_source_destroy(iwp->src);
         g_source_unref(iwp->src);
@@ -919,7 +919,7 @@ static guint io_add_watch_poll(QIOChannel *ioc,
     iwp->fd_read = (GSourceFunc) fd_read;
     iwp->src = NULL;
 
-    tag = g_source_attach(&iwp->parent, NULL);
+    tag = g_source_attach(&iwp->parent, g_main_context_get_thread_default());
     g_source_unref(&iwp->parent);
     return tag;
 }
@@ -3983,7 +3983,7 @@ int qemu_chr_fe_add_watch(CharDriverState *s, GIOCondition cond,
     }
 
     g_source_set_callback(src, (GSourceFunc)func, user_data, NULL);
-    tag = g_source_attach(src, NULL);
+    tag = g_source_attach(src, g_main_context_get_thread_default());
     g_source_unref(src);
 
     return tag;
-- 
2.7.4

[Qemu-devel] [RFC PATCH V7 0/7] Introduce COLO-compare

[Zhang Chen]

COLO-compare is a part of COLO project. It is used
to compare the network package to help COLO decide
whether to do checkpoint.

The full version in this github:
https://github.com/zhangckid/qemu/tree/colo-v2.7-proxy-mode-compare-with-colo-base-jul18


v7:
 p5:
   - add [PATCH]qemu-char: Fix context for g_source_attach()
     in this patch series.

v6: 
 p6:
   - add more commit log.
   - fix icmp comparison to compare all packet.

 p5:
   - add more cpmments in commit log.
   - change REGULAR_CHECK_MS to REGULAR_PACKET_CHECK_MS
   - make check old packet independent to compare thread
   - remove thread_status

 p4:
   - change this patch only about
     Connection and ConnectionKey.
   - add some comments in commit log.
   - remove mode in fill_connection_key().
   - fix some comments and bug.
   - move colo_conn_state to patch of
     "work with colo-frame"
   - remove conn_list_lock.
   - add MAX_QUEUE_SIZE, if primary_list or
     secondary_list biger than MAX_QUEUE_SIZE
     we will drop packet. 

 p3:
   - add new independent kernel jhash patch.

 p2:
   - add new independent colo-base patch.

 p1:
   - add a ascii figure and some comments to explain it
   - move trace.h to p2
   - move QTAILQ_HEAD(, CompareState) net_compares to
     patch of "work with colo-frame"
   - add some comments in qemu-option.hx


v5:
 p3:
    - comments from Jason
      we poll and handle chardev in comapre thread,
      Through this way, there's no need for extra 
      synchronization with main loop
      this depend on another patch:
      qemu-char: Fix context for g_source_attach()
    - remove QemuEvent
 p2:
    - remove conn->list_lock
 p1:
    - move compare_pri/sec_chr_in to p3
    - move compare_chr_send to p2

v4:
 p4:
    - add some comments
    - fix some trace-events
    - fix tcp compare error
 p3:
    - add rcu_read_lock().
    - fix trace name
    - fix jason's other comments
    - rebase some Dave's branch function
 p2:
    - colo_compare_connection() change g_queue_push_head() to
    - g_queue_push_tail() match to sorted order.
    - remove pkt->s
    - move data structure to colo-base.h
    - add colo-base.c reuse codes for filter-rewriter
    - add some filter-rewriter needs struct
    - depends on previous SocketReadState patch
 p1:
    - except move qemu_chr_add_handlers()
      to colo thread
    - remove class_finalize
    - remove secondary arp codes
    - depends on previous SocketReadState patch

v3:
  - rebase colo-compare to colo-frame v2.7
  - fix most of Dave's comments
    (except RCU)
  - add TCP,UDP,ICMP and other packet comparison
  - add trace-event
  - add some comments
  - other bug fix
  - add RFC index
  - add usage in patch 1/4

v2:
  - add jhash.h

v1:
  - initial patch


Zhang Chen (7):
  colo-compare: introduce colo compare initialization
  colo-base: add colo-base to define and handle packet
  Jhash: add linux kernel jhashtable in qemu
  colo-compare: track connection and enqueue packet
  qemu-char: Fix context for g_source_attach()
  colo-compare: introduce packet comparison thread
  colo-compare: add TCP,UDP,ICMP packet comparison

 include/qemu/jhash.h |  61 ++++
 io/channel.c         |   2 +-
 net/Makefile.objs    |   2 +
 net/colo-base.c      | 183 ++++++++++++
 net/colo-base.h      |  71 +++++
 net/colo-compare.c   | 769 +++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-char.c          |   6 +-
 qemu-options.hx      |  38 +++
 trace-events         |   9 +
 vl.c                 |   3 +-
 10 files changed, 1139 insertions(+), 5 deletions(-)
 create mode 100644 include/qemu/jhash.h
 create mode 100644 net/colo-base.c
 create mode 100644 net/colo-base.h
 create mode 100644 net/colo-compare.c

-- 
2.7.4

[Qemu-devel] [RFC PATCH V7 5/7] qemu-char: Fix context for g_source_attach()

[Zhang Chen]

We want to poll and handle chardev in another thread
other than main loop. But qemu_chr_add_handlers() can only
work for global default context other than thread default context.
So we use g_source_attach(xx, g_main_context_get_thread_default())
replace g_source_attach(xx, NULL) to attach g_source.
Comments from jason.

Cc: Daniel P . Berrange <berrange@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 io/channel.c | 2 +-
 qemu-char.c  | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/io/channel.c b/io/channel.c
index 692eb17..cd25677 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -146,7 +146,7 @@ guint qio_channel_add_watch(QIOChannel *ioc,
 
     g_source_set_callback(source, (GSourceFunc)func, user_data, notify);
 
-    id = g_source_attach(source, NULL);
+    id = g_source_attach(source, g_main_context_get_thread_default());
     g_source_unref(source);
 
     return id;
diff --git a/qemu-char.c b/qemu-char.c
index b597ee1..ed7e1f7 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -860,7 +860,7 @@ static gboolean io_watch_poll_prepare(GSource *source, gint *timeout_)
         iwp->src = qio_channel_create_watch(
             iwp->ioc, G_IO_IN | G_IO_ERR | G_IO_HUP | G_IO_NVAL);
         g_source_set_callback(iwp->src, iwp->fd_read, iwp->opaque, NULL);
-        g_source_attach(iwp->src, NULL);
+        g_source_attach(iwp->src, g_main_context_get_thread_default());
     } else {
         g_source_destroy(iwp->src);
         g_source_unref(iwp->src);
@@ -919,7 +919,7 @@ static guint io_add_watch_poll(QIOChannel *ioc,
     iwp->fd_read = (GSourceFunc) fd_read;
     iwp->src = NULL;
 
-    tag = g_source_attach(&iwp->parent, NULL);
+    tag = g_source_attach(&iwp->parent, g_main_context_get_thread_default());
     g_source_unref(&iwp->parent);
     return tag;
 }
@@ -3983,7 +3983,7 @@ int qemu_chr_fe_add_watch(CharDriverState *s, GIOCondition cond,
     }
 
     g_source_set_callback(src, (GSourceFunc)func, user_data, NULL);
-    tag = g_source_attach(src, NULL);
+    tag = g_source_attach(src, g_main_context_get_thread_default());
     g_source_unref(src);
 
     return tag;
-- 
2.7.4

Re: [Qemu-devel] [RFC PATCH V7 5/7] qemu-char: Fix context for g_source_attach()

[Daniel P. Berrange]

On Mon, Jul 18, 2016 at 03:40:48PM +0800, Zhang Chen wrote:
> We want to poll and handle chardev in another thread
> other than main loop. But qemu_chr_add_handlers() can only
> work for global default context other than thread default context.
> So we use g_source_attach(xx, g_main_context_get_thread_default())
> replace g_source_attach(xx, NULL) to attach g_source.
> Comments from jason.
> 
> Cc: Daniel P . Berrange <berrange@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> 
> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  io/channel.c | 2 +-
>  qemu-char.c  | 6 +++---
>  2 files changed, 4 insertions(+), 4 deletions(-)

So, on further reflection I'm against adding this patch - please see
my comments against the next patch for why I think this is not needed
nor desirable.

Regards,
Daniel
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