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authorPaolo Bonzini <pbonzini@redhat.com>2014-12-11 14:52:30 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2014-12-12 16:57:55 +0000
commit82595da8dedde128d8004ec47441aeb720c08704 (patch)
tree7be4908dfc8a445a28a622ecd514f81ea31619bb
parentde35464461cd8aa764ce03e8026202fe9861e29d (diff)
linux-aio: simplify removal of completed iocbs from the list
There is no need to do another O(n) pass on the list; the iocb to split the list at is already available through the array we passed to io_submit. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1418305950-30924-6-git-send-email-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--block/linux-aio.c12
-rw-r--r--include/qemu/queue.h11
2 files changed, 17 insertions, 6 deletions
diff --git a/block/linux-aio.c b/block/linux-aio.c
index 8474378fc2..c991443c5d 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -186,9 +186,10 @@ static void ioq_init(LaioQueue *io_q)
static void ioq_submit(struct qemu_laio_state *s)
{
- int ret, i, len;
+ int ret, len;
struct qemu_laiocb *aiocb;
struct iocb *iocbs[MAX_QUEUED_IO];
+ QSIMPLEQ_HEAD(, qemu_laiocb) completed;
do {
len = 0;
@@ -201,16 +202,15 @@ static void ioq_submit(struct qemu_laio_state *s)
ret = io_submit(s->ctx, len, iocbs);
if (ret == -EAGAIN) {
- ret = 0;
+ break;
}
if (ret < 0) {
abort();
}
- for (i = 0; i < ret; i++) {
- s->io_q.n--;
- QSIMPLEQ_REMOVE_HEAD(&s->io_q.pending, next);
- }
+ s->io_q.n -= ret;
+ aiocb = container_of(iocbs[ret - 1], struct qemu_laiocb, iocb);
+ QSIMPLEQ_SPLIT_AFTER(&s->io_q.pending, aiocb, next, &completed);
} while (ret == len && !QSIMPLEQ_EMPTY(&s->io_q.pending));
s->io_q.blocked = (s->io_q.n > 0);
}
diff --git a/include/qemu/queue.h b/include/qemu/queue.h
index d433b9017c..42bcadfbb1 100644
--- a/include/qemu/queue.h
+++ b/include/qemu/queue.h
@@ -268,6 +268,17 @@ struct { \
(head)->sqh_last = &(head)->sqh_first; \
} while (/*CONSTCOND*/0)
+#define QSIMPLEQ_SPLIT_AFTER(head, elm, field, removed) do { \
+ QSIMPLEQ_INIT(removed); \
+ if (((removed)->sqh_first = (head)->sqh_first) != NULL) { \
+ if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) { \
+ (head)->sqh_last = &(head)->sqh_first; \
+ } \
+ (removed)->sqh_last = &(elm)->field.sqe_next; \
+ (elm)->field.sqe_next = NULL; \
+ } \
+} while (/*CONSTCOND*/0)
+
#define QSIMPLEQ_REMOVE(head, elm, type, field) do { \
if ((head)->sqh_first == (elm)) { \
QSIMPLEQ_REMOVE_HEAD((head), field); \