diff mbox

[07/16] coroutine-lock: reschedule coroutine on the AioContext it was running on

Message ID 20170113131731.1246-8-pbonzini@redhat.com
State New
Headers show

Commit Message

Paolo Bonzini Jan. 13, 2017, 1:17 p.m. UTC 
As a small step towards the introduction of multiqueue, we want
coroutines to remain on the same AioContext that started them,
unless they are moved explicitly with e.g. aio_co_schedule.  This patch
avoids that coroutines switch AioContext when they use a CoMutex.
For now it does not make much of a difference, because the CoMutex
is not thread-safe and the AioContext itself is used to protect the
CoMutex from concurrent access.  However, this is going to change.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 util/qemu-coroutine-lock.c | 5 ++---
 util/trace-events          | 1 -
 2 files changed, 2 insertions(+), 4 deletions(-)

Comments

Stefan Hajnoczi Jan. 18, 2017, 3:26 p.m. UTC | #1 
On Fri, Jan 13, 2017 at 02:17:22PM +0100, Paolo Bonzini wrote:
> As a small step towards the introduction of multiqueue, we want
> coroutines to remain on the same AioContext that started them,
> unless they are moved explicitly with e.g. aio_co_schedule.  This patch
> avoids that coroutines switch AioContext when they use a CoMutex.
> For now it does not make much of a difference, because the CoMutex
> is not thread-safe and the AioContext itself is used to protect the
> CoMutex from concurrent access.  However, this is going to change.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  util/qemu-coroutine-lock.c | 5 ++---
>  util/trace-events          | 1 -
>  2 files changed, 2 insertions(+), 4 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff mbox

Patch

diff --git a/util/qemu-coroutine-lock.c b/util/qemu-coroutine-lock.c
index 14cf9ce..e6afd1a 100644
--- a/util/qemu-coroutine-lock.c
+++ b/util/qemu-coroutine-lock.c
@@ -27,6 +27,7 @@ 
 #include "qemu/coroutine.h"
 #include "qemu/coroutine_int.h"
 #include "qemu/queue.h"
+#include "block/aio.h"
 #include "trace.h"
 
 void qemu_co_queue_init(CoQueue *queue)
@@ -63,7 +64,6 @@  void qemu_co_queue_run_restart(Coroutine *co)
 
 static bool qemu_co_queue_do_restart(CoQueue *queue, bool single)
 {
-    Coroutine *self = qemu_coroutine_self();
     Coroutine *next;
 
     if (QSIMPLEQ_EMPTY(&queue->entries)) {
@@ -72,8 +72,7 @@  static bool qemu_co_queue_do_restart(CoQueue *queue, bool single)
 
     while ((next = QSIMPLEQ_FIRST(&queue->entries)) != NULL) {
         QSIMPLEQ_REMOVE_HEAD(&queue->entries, co_queue_next);
-        QSIMPLEQ_INSERT_TAIL(&self->co_queue_wakeup, next, co_queue_next);
-        trace_qemu_co_queue_next(next);
+        aio_co_wake(next);
         if (single) {
             break;
         }
diff --git a/util/trace-events b/util/trace-events
index 2b8aa30..65705c4 100644
--- a/util/trace-events
+++ b/util/trace-events
@@ -13,7 +13,6 @@  qemu_coroutine_terminate(void *co) "self %p"
 
 # util/qemu-coroutine-lock.c
 qemu_co_queue_run_restart(void *co) "co %p"
-qemu_co_queue_next(void *nxt) "next %p"
 qemu_co_mutex_lock_entry(void *mutex, void *self) "mutex %p self %p"
 qemu_co_mutex_lock_return(void *mutex, void *self) "mutex %p self %p"
 qemu_co_mutex_unlock_entry(void *mutex, void *self) "mutex %p self %p"