On Do, 2015-08-27 at 11:39 +0100, Daniel P. Berrange wrote:
> On Thu, Aug 27, 2015 at 12:18:52PM +0200, Peter Lieven wrote:
> > currently the Buffer can only grow. This increases Qemu memory footprint
> > dramatically since normally the biggest VNC updates are at connection time.
> > But also after a VNC session has terminated there is one persistent buffer
> > in queue->buffer which I have seen to increase to over 100MB and it is never
> > getting smaller again.
>
> Do you have any idea what caused the buffer to increase to 100MB in size
> in the first place ? I would expect a full screen update would cause the
> biggest buffer usage, and even for a 1920x1140 screen that should not
> be anywhere near 100MB in size. IOW, i'm wondering if the 100MB usage
> is symptomatic of a more serious bug somewhere else in the VNC code
> that you're just masking you reducing buffer size afterwards.
Cooked up a buffer stats patch (attached).
Buffer sizes are nowhere near 100MB for me (as expected by Daniel).
Individual buffers are in the 1 -> 4 MB range (1920x1080), even summed
up this is more like 10 not 100 MB.
So, big question remains why they are that big for you?
Beside that I think it makes sense to have the shrinking logic in
buffer_reserve too so we don't have to add buffer_shrink calls all over
the place.
cheers,
Gerd
From e5d9353d02983db0081e44026767adf9f5a72832 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kra...@redhat.com>
Date: Thu, 3 Sep 2015 11:44:18 +0200
Subject: [PATCH] [debug] vnc buffer stats
---
ui/vnc-jobs.c | 1 +
ui/vnc.c | 38 ++++++++++++++++++++++++++++++++++++++
ui/vnc.h | 2 ++
3 files changed, 41 insertions(+)
diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index 22c9abc..1338771 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -302,6 +302,7 @@ static VncJobQueue *vnc_queue_init(void)
qemu_cond_init(&queue->cond);
qemu_mutex_init(&queue->mutex);
+ buffer_init(&queue->buffer, 0, "queue");
QTAILQ_INIT(&queue->jobs);
return queue;
}
diff --git a/ui/vnc.c b/ui/vnc.c
index 7a17954..59be765 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -655,12 +655,29 @@ void vnc_framebuffer_update(VncState *vs, int x, int y, int w, int h,
#define BUFFER_MIN_INIT_SIZE 4096
+void buffer_init(Buffer *buffer, int fd, const char *name)
+{
+ if (fd) {
+ buffer->name = g_strdup_printf("%d/%s", fd, name);
+ } else {
+ buffer->name = g_strdup(name);
+ }
+}
+
void buffer_reserve(Buffer *buffer, size_t len)
{
+ bool inc = false;
+
+ assert(buffer->name);
if ((buffer->capacity - buffer->offset) < len) {
buffer->capacity = pow2ceil(buffer->capacity + len);
buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_INIT_SIZE);
buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
+ inc = true;
+ }
+ if (inc) {
+ fprintf(stderr, "%s: %-10s: %4zd kB\n", __func__,
+ buffer->name, buffer->capacity / 1024);
}
}
@@ -681,6 +698,7 @@ void buffer_reset(Buffer *buffer)
void buffer_free(Buffer *buffer)
{
+ fprintf(stderr, "%s: %s\n", __func__, buffer->name);
g_free(buffer->buffer);
buffer->offset = 0;
buffer->capacity = 0;
@@ -3027,6 +3045,26 @@ static void vnc_connect(VncDisplay *vd, int csock,
vs->csock = csock;
vs->vd = vd;
+ buffer_init(&vs->input, vs->csock, "in");
+ buffer_init(&vs->output, vs->csock, "out");
+ buffer_init(&vs->ws_input, vs->csock, "w-in");
+ buffer_init(&vs->ws_output, vs->csock, "w-out");
+ buffer_init(&vs->jobs_buffer, vs->csock, "jobs");
+
+ buffer_init(&vs->tight.tight, vs->csock, "t-tight");
+ buffer_init(&vs->tight.zlib, vs->csock, "t-zlib");
+ buffer_init(&vs->tight.gradient, vs->csock, "t-gradient");
+#ifdef CONFIG_VNC_JPEG
+ buffer_init(&vs->tight.jpeg, vs->csock, "t-jpeg");
+#endif
+#ifdef CONFIG_VNC_PNG
+ buffer_init(&vs->tight.png, vs->csock, "t-png");
+#endif
+ buffer_init(&vs->zlib.zlib, vs->csock, "zlib");
+ buffer_init(&vs->zrle.zrle, vs->csock, "z-zrle");
+ buffer_init(&vs->zrle.fb, vs->csock, "z-fb");
+ buffer_init(&vs->zrle.zlib, vs->csock, "z-zlib");
+
if (skipauth) {
vs->auth = VNC_AUTH_NONE;
vs->subauth = VNC_AUTH_INVALID;
diff --git a/ui/vnc.h b/ui/vnc.h
index 814d720..95878c3 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -57,6 +57,7 @@
typedef struct Buffer
{
+ char *name;
size_t capacity;
size_t offset;
uint8_t *buffer;
@@ -539,6 +540,7 @@ void start_client_init(VncState *vs);
void start_auth_vnc(VncState *vs);
/* Buffer management */
+void buffer_init(Buffer *buffer, int fd, const char *name);
void buffer_reserve(Buffer *buffer, size_t len);
void buffer_reset(Buffer *buffer);
void buffer_free(Buffer *buffer);
--
1.8.3.1
