commit 82595da8dedde128d8004ec47441aeb720c08704
author Paolo Bonzini <pbonzini@redhat.com> Thu Dec 11 14:52:30 2014 +0100
committer Stefan Hajnoczi <stefanha@redhat.com> Fri Dec 12 16:57:55 2014 +0000
tree 7be4908dfc8a445a28a622ecd514f81ea31619bb
parent de35464461cd8aa764ce03e8026202fe9861e29d

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>

block/linux-aio.c

diff --git a/block/linux-aio.c b/block/linux-aio.c
index 8474378..c991443 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -186,9 +186,10 @@
 
 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 @@
 
         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);
 }