Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block patches

# gpg: Signature made Fri 15 Aug 2014 14:07:42 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (59 commits)
  block: Catch !bs->drv in bdrv_check()
  iotests: Add test for image header overlap
  qcow2: Catch !*host_offset for data allocation
  qcow2: Return useful error code in refcount_init()
  mirror: Handle failure for potentially large allocations
  vpc: Handle failure for potentially large allocations
  vmdk: Handle failure for potentially large allocations
  vhdx: Handle failure for potentially large allocations
  vdi: Handle failure for potentially large allocations
  rbd: Handle failure for potentially large allocations
  raw-win32: Handle failure for potentially large allocations
  raw-posix: Handle failure for potentially large allocations
  qed: Handle failure for potentially large allocations
  qcow2: Handle failure for potentially large allocations
  qcow1: Handle failure for potentially large allocations
  parallels: Handle failure for potentially large allocations
  nfs: Handle failure for potentially large allocations
  iscsi: Handle failure for potentially large allocations
  dmg: Handle failure for potentially large allocations
  curl: Handle failure for potentially large allocations
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 23 insertions, 3 deletions

diff --git a/qemu-coroutine.c b/qemu-coroutine.c
index 470852100a..bd574aa1b5 100644
--- a/qemu-coroutine.c
+++ b/qemu-coroutine.c
@@ -19,14 +19,14 @@
 #include "block/coroutine_int.h"
 
 enum {
-    /* Maximum free pool size prevents holding too many freed coroutines */
-    POOL_MAX_SIZE = 64,
+    POOL_DEFAULT_SIZE = 64,
 };
 
 /** Free list to speed up creation */
 static QemuMutex pool_lock;
 static QSLIST_HEAD(, Coroutine) pool = QSLIST_HEAD_INITIALIZER(pool);
 static unsigned int pool_size;
+static unsigned int pool_max_size = POOL_DEFAULT_SIZE;
 
 Coroutine *qemu_coroutine_create(CoroutineEntry *entry)
 {
@@ -55,7 +55,7 @@ static void coroutine_delete(Coroutine *co)
 {
     if (CONFIG_COROUTINE_POOL) {
         qemu_mutex_lock(&pool_lock);
-        if (pool_size < POOL_MAX_SIZE) {
+        if (pool_size < pool_max_size) {
             QSLIST_INSERT_HEAD(&pool, co, pool_next);
             co->caller = NULL;
             pool_size++;
@@ -137,3 +137,23 @@ void coroutine_fn qemu_coroutine_yield(void)
     self->caller = NULL;
     coroutine_swap(self, to);
 }
+
+void qemu_coroutine_adjust_pool_size(int n)
+{
+    qemu_mutex_lock(&pool_lock);
+
+    pool_max_size += n;
+
+    /* Callers should never take away more than they added */
+    assert(pool_max_size >= POOL_DEFAULT_SIZE);
+
+    /* Trim oversized pool down to new max */
+    while (pool_size > pool_max_size) {
+        Coroutine *co = QSLIST_FIRST(&pool);
+        QSLIST_REMOVE_HEAD(&pool, pool_next);
+        pool_size--;
+        qemu_coroutine_delete(co);
+    }
+
+    qemu_mutex_unlock(&pool_lock);
+}