[Qemu-devel] [PATCH V8 6/6] coroutine: reduce stack size to 60kB

[Peter Lieven <pl@kamp.de>]

evaluation with the recently introduced maximum stack usage monitoring revealed
that the actual used stack size was never above 4kB so allocating 1MB stack
for each coroutine is a lot of wasted memory. So reduce the stack size to
60kB which should still give enough head room. The guard page added
in qemu_alloc_stack will catch a potential stack overflow introduced
by this commit. The 60kB + guard page will result in an allocation of
64kB per coroutine on systems where a page is 4kB.

Signed-off-by: Peter Lieven <pl@kamp.de>
---
 include/qemu/coroutine_int.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/qemu/coroutine_int.h b/include/qemu/coroutine_int.h
index 14d4f1d..be14260 100644
--- a/include/qemu/coroutine_int.h
+++ b/include/qemu/coroutine_int.h
@@ -28,7 +28,7 @@
 #include "qemu/queue.h"
 #include "qemu/coroutine.h"
 
-#define COROUTINE_STACK_SIZE (1 << 20)
+#define COROUTINE_STACK_SIZE 61440
 
 typedef enum {
     COROUTINE_YIELD = 1,
-- 
1.9.1