Commit a9d92355 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Stefan Hajnoczi
Browse files

coroutine-lock: reschedule coroutine on the AioContext it was running on 



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.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarDaniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-9-pbonzini@redhat.com
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent ff82911c

util/qemu-coroutine-lock.c

+2 −3
Original line number Diff line number Diff line
@@ -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;

        }

util/trace-events

+0 −1
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ 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"