[Qemu-devel] [PATCH] hw/dma: Print error message only once

[Qemu-devel] [PATCH] hw/dma: Print error message only once

[Philipp Hahn]

otherwise the message
	dma: unregistered DMA channel used nchan=0 dma_pos=0 dma_len=1
gets printed every time and fills up the log-file with 50 MiB / minute.

Signed-off-by: Philipp Hahn <hahn@univention.de>
---
 hw/dma/i8257.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/hw/dma/i8257.c b/hw/dma/i8257.c
index dd370ed..9673ab6 100644
--- a/hw/dma/i8257.c
+++ b/hw/dma/i8257.c
@@ -473,8 +473,14 @@ static void dma_reset(void *opaque)
 
 static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len)
 {
-    dolog ("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
-           nchan, dma_pos, dma_len);
+    static int once;
+    int mask = 1 << nchan;
+
+    if (0 == (once & mask)) {
+        once |= mask;
+        dolog("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
+              nchan, dma_pos, dma_len);
+    }
     return dma_pos;
 }
 
-- 
1.9.1

Re: [Qemu-devel] [PATCH] hw/dma: Print error message only once

[Paolo Bonzini]

Il 09/09/2014 09:01, Philipp Hahn ha scritto:
> otherwise the message
> 	dma: unregistered DMA channel used nchan=0 dma_pos=0 dma_len=1
> gets printed every time and fills up the log-file with 50 MiB / minute.
> 
> Signed-off-by: Philipp Hahn <hahn@univention.de>
> ---
>  hw/dma/i8257.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/dma/i8257.c b/hw/dma/i8257.c
> index dd370ed..9673ab6 100644
> --- a/hw/dma/i8257.c
> +++ b/hw/dma/i8257.c
> @@ -473,8 +473,14 @@ static void dma_reset(void *opaque)
>  
>  static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len)
>  {
> -    dolog ("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
> -           nchan, dma_pos, dma_len);
> +    static int once;
> +    int mask = 1 << nchan;
> +
> +    if (0 == (once & mask)) {
> +        once |= mask;
> +        dolog("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
> +              nchan, dma_pos, dma_len);
> +    }
>      return dma_pos;
>  }
>  
> 

Can you just convert it to a tracepoint and remove the message?

Thanks,

Paolo

[Qemu-devel] [PATCH v2] hw/dma/i8257: Silence phony error message

[Philipp Hahn]

Convert into trace event. Otherwise the message
	dma: unregistered DMA channel used nchan=0 dma_pos=0 dma_len=1
gets printed every time and fills up the log-file with 50 MiB / minute.

Signed-off-by: Philipp Hahn <hahn@univention.de>
---
 v2:
   Convert into trace event instead of tracking once per static bitmap.
---
 hw/dma/i8257.c | 4 ++--
 trace-events   | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/hw/dma/i8257.c b/hw/dma/i8257.c
index dd370ed..a414029 100644
--- a/hw/dma/i8257.c
+++ b/hw/dma/i8257.c
@@ -24,6 +24,7 @@
 #include "hw/hw.h"
 #include "hw/isa/isa.h"
 #include "qemu/main-loop.h"
+#include "trace.h"
 
 /* #define DEBUG_DMA */
 
@@ -473,8 +474,7 @@ static void dma_reset(void *opaque)
 
 static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len)
 {
-    dolog ("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
-           nchan, dma_pos, dma_len);
+    trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
     return dma_pos;
 }
 
diff --git a/trace-events b/trace-events
index 03ac5d2..c12afc0 100644
--- a/trace-events
+++ b/trace-events
@@ -1318,3 +1318,6 @@ mhp_pc_dimm_assigned_address(uint64_t addr) "0x%"PRIx64
 # target-s390x/kvm.c
 kvm_enable_cmma(int rc) "CMMA: enabling with result code %d"
 kvm_clear_cmma(int rc) "CMMA: clearing with result code %d"
+
+# hw/dma/i8257.c
+i8257_unregistered_dma(int nchan, int dma_pos, int dma_len) "unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d"
-- 
1.9.1