[dpdk-dev] doc: add limitation for L3fwd-power app

Message ID 1478263697-57575-1-git-send-email-pablo.de.lara.guarch@intel.com (mailing list archive)
State Accepted, archived
Headers

Checks

Context Check Description
tmonjalo/checkpatch success coding style OK

Commit Message

De Lara Guarch, Pablo Nov. 4, 2016, 12:48 p.m. UTC
  L3fwd-power app needs vector mode to be disabled in order to work
properly. The app used to work previously, because it was using
Rx scalar function, but now it uses vector function.

Vector mode needs to be disabled to make the app works,
which has been documented in release notes.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 doc/guides/rel_notes/release_16_11.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)
  

Comments

John McNamara Nov. 4, 2016, 1:04 p.m. UTC | #1
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Pablo de Lara
> Sent: Friday, November 4, 2016 12:48 PM
> To: dev@dpdk.org
> Cc: De Lara Guarch, Pablo <pablo.de.lara.guarch@intel.com>
> Subject: [dpdk-dev] [PATCH] doc: add limitation for L3fwd-power app
> 
> L3fwd-power app needs vector mode to be disabled in order to work
> properly. The app used to work previously, because it was using Rx scalar
> function, but now it uses vector function.
> 
> Vector mode needs to be disabled to make the app works, which has been
> documented in release notes.
> 
> Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>

Acked-by: John McNamara <john.mcnamara@intel.com>
  
Thomas Monjalon Nov. 4, 2016, 5 p.m. UTC | #2
2016-11-04 12:48, Pablo de Lara:
> L3fwd-power requires the mbuf to have correct packet type,
> but in some drivers, the vector mode must be disabled for this.

This is a severe bug.
We must really fix packet type handling to have a constant support
whatever the driver or options.
  
De Lara Guarch, Pablo Nov. 4, 2016, 6:27 p.m. UTC | #3
Hi Thomas,

> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
> Sent: Friday, November 04, 2016 5:00 PM
> To: De Lara Guarch, Pablo
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] doc: add limitation for L3fwd-power app
> 
> 2016-11-04 12:48, Pablo de Lara:
> > L3fwd-power requires the mbuf to have correct packet type,
> > but in some drivers, the vector mode must be disabled for this.
> 
> This is a severe bug.
> We must really fix packet type handling to have a constant support
> whatever the driver or options.

This is already documented in previous release (2.2).
Actually, the main problem for L3fwd-power app is not the packet type,
but the descriptor_done for the Rx vector function, that works differently
compared to the scalar function.

Thanks,
Pablo
  
Thomas Monjalon Nov. 7, 2016, 9:06 p.m. UTC | #4
> > L3fwd-power app needs vector mode to be disabled in order to work
> > properly. The app used to work previously, because it was using Rx scalar
> > function, but now it uses vector function.
> > 
> > Vector mode needs to be disabled to make the app works, which has been
> > documented in release notes.
> > 
> > Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
> 
> Acked-by: John McNamara <john.mcnamara@intel.com>

Applied, thanks
  

Patch

diff --git a/doc/guides/rel_notes/release_16_11.rst b/doc/guides/rel_notes/release_16_11.rst
index aa0c09a..cb4ec97 100644
--- a/doc/guides/rel_notes/release_16_11.rst
+++ b/doc/guides/rel_notes/release_16_11.rst
@@ -178,6 +178,17 @@  Known Issues
 
    This section is a comment. Make sure to start the actual text at the margin.
 
+* **L3fwd-power app does not work properly when Rx vector is enabled.**
+
+  Using some drivers with vector enabled, makes L3fwd-power app not work
+  properly, since the queue monitoring works differently when using
+  scalar compared to vector, making the frequency scaling not to work correctly.
+  In addition, L3fwd-power requires the mbuf to have correct packet type,
+  but in some drivers, the vector mode must be disabled for this.
+
+  Therefore, in order to use L3fwd-power, vector mode should be disabled
+  from the config file.
+
 
 API Changes
 -----------