[virglrenderer-devel] memory leak on resource_create/destroy

[Zhu Yijun]

hi all,

I run monkey test on an android guest which is booted by qemu with
virtual 3D GPU(virgl=on), and find the host used memory increases
continuously. Then use valrand to memcheck qemu process, there are
some blocks of memory leak reported:

==5730== 188,640 bytes in 524 blocks are definitely lost in loss
record 10,169 of 10,189 ==5730== at 0x485959C: calloc
(vg_replace_malloc.c:762)
==5730== by 0x48BEAC7: vrend_renderer_resource_create
(vrend_renderer.c:6649) ==5730== by 0x31E04F:
virgl_cmd_create_resource_3d (virtio-gpu-3d.c:72)
==5730== by 0x31E04F: virtio_gpu_virgl_process_cmd (virtio-gpu-3d.c:419)
==5730== by 0x31BFDB: virtio_gpu_process_cmdq (virtio-gpu.c:888)
==5730== by 0x31CFE3: virtio_gpu_handle_ctrl (virtio-gpu.c:936)
==5730== by 0x31CFE3: virtio_gpu_ctrl_bh (virtio-gpu.c:948)
==5730== by 0x579723: aio_bh_call (async.c:90)
==5730== by 0x579723: aio_bh_poll (async.c:118)
==5730== by 0x57CA03: aio_dispatch (aio-posix.c:461)
==5730== by 0x5795EB: aio_ctx_dispatch (async.c:269)
==5730== by 0x5051E9F: g_main_context_dispatch (in
/usr/lib64/libglib-2.0.so.0.5600.1) ==5730== by 0x57BB93:
glib_pollfds_poll (main-loop.c:215)
==5730== by 0x57BB93: os_host_main_loop_wait (main-loop.c:238)
==5730== by 0x57BB93: main_loop_wait (main-loop.c:497)
==5730== by 0x29956B: main_loop (vl.c:1982)
==5730== by 0x29956B: main (vl.c:4926)

Check the code below, the possible cause is that the reference count
of resource is not zero and then resource will not destroy immediately
once qemu calls VIRTIO_GPU_CMD_RESOURCE_UNREF cmd. It means the res is
still used by surface, sampler_view, so_target and so on objects which
are called "vrend_resource_reference", it looks reasonable.

static void vrend_destroy_resource_object(void *obj_ptr)
{
   struct vrend_resource *res = obj_ptr;

   if (pipe_reference(&res->base.reference, NULL))
       vrend_renderer_resource_destroy(res);
}

However, I find some resources may not be destroyed finally. I add
some printf in qemu and virgl code, when android guest turning off,
qemu receive the right number of VIRTIO_GPU_CMD_RESOURCE_UNREF cmds
from guest created before, but virgl still remain some resources not
destroy finally and cause the vrend_source not free.

So is it the issue of android guest or virglrenderer or else part, it
should not have memory leak anyway, right?

Thanks!

Yijun