diff mbox series

[4/4] doc: improve vhost zero copy guide

Message ID 20190222024209.30879-5-tiwei.bie@intel.com (mailing list archive)
State Accepted, archived
Delegated to: Maxime Coquelin
Headers
Series Some fixes for vhost zero copy |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Tiwei Bie Feb. 22, 2019, 2:42 a.m. UTC 
  Highlight that vhost zero copy mbufs should be consumed
as soon as possible.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
 doc/guides/prog_guide/vhost_lib.rst | 3 +++
 1 file changed, 3 insertions(+)

Comments

Maxime Coquelin Feb. 26, 2019, 2:44 p.m. UTC | #1 
On 2/22/19 3:42 AM, Tiwei Bie wrote:
> Highlight that vhost zero copy mbufs should be consumed
> as soon as possible.
> 
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> ---
>   doc/guides/prog_guide/vhost_lib.rst | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
> index c77df338f..a86c07a62 100644
> --- a/doc/guides/prog_guide/vhost_lib.rst
> +++ b/doc/guides/prog_guide/vhost_lib.rst
> @@ -92,6 +92,9 @@ The following is an overview of some key Vhost API functions:
>         to use vfio-pci driver, please insert vfio-pci kernel module in noiommu
>         mode.
>   
> +    * The consumer of zero copy mbufs should consume these mbufs as soon as
> +      possible, otherwise it may block the operations in vhost.
> +
>     - ``RTE_VHOST_USER_IOMMU_SUPPORT``
>   
>       IOMMU support will be enabled when this flag is set. It is disabled by
> 

Indeed, and it may also block QEMU. That's what I find really fragile
with dequeue zero-copy.

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime
diff mbox series

Patch

diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
index c77df338f..a86c07a62 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -92,6 +92,9 @@  The following is an overview of some key Vhost API functions:
       to use vfio-pci driver, please insert vfio-pci kernel module in noiommu
       mode.
 
+    * The consumer of zero copy mbufs should consume these mbufs as soon as
+      possible, otherwise it may block the operations in vhost.
+
   - ``RTE_VHOST_USER_IOMMU_SUPPORT``
 
     IOMMU support will be enabled when this flag is set. It is disabled by