diff mbox series

[v2,02/12] block/nvme: Avoid further processing if trace event not enabled

Message ID 20200630191318.30021-3-philmd@redhat.com (mailing list archive)
State New, archived
Headers show
Series block/nvme: Various cleanups required to use multiple queues | expand

Commit Message

Philippe Mathieu-Daudé June 30, 2020, 7:13 p.m. UTC 
Avoid further processing if TRACE_NVME_SUBMIT_COMMAND_RAW is
not enabled. This is an untested intend of performance optimization.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 block/nvme.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Stefan Hajnoczi July 1, 2020, 3:48 p.m. UTC | #1 
On Tue, Jun 30, 2020 at 09:13:08PM +0200, Philippe Mathieu-Daudé wrote:
> Avoid further processing if TRACE_NVME_SUBMIT_COMMAND_RAW is
> not enabled. This is an untested intend of performance optimization.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  block/nvme.c | 3 +++
>  1 file changed, 3 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff mbox series

Patch

diff --git a/block/nvme.c b/block/nvme.c
index 2f5e3c2adf..8c30a5fee2 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -441,6 +441,9 @@  static void nvme_trace_command(const NvmeCmd *cmd)
 {
     int i;
 
+    if (!trace_event_get_state_backends(TRACE_NVME_SUBMIT_COMMAND_RAW)) {
+        return;
+    }
     for (i = 0; i < 8; ++i) {
         uint8_t *cmdp = (uint8_t *)cmd + i * 8;
         trace_nvme_submit_command_raw(cmdp[0], cmdp[1], cmdp[2], cmdp[3],