patches for DPDK stable branches
 help / color / mirror / Atom feed
* [PATCH] latencystats: fix missing f suffix on literal float
@ 2024-04-15 21:32 Tyler Retzlaff
  2024-04-15 22:17 ` Stephen Hemminger
  0 siblings, 1 reply; 4+ messages in thread
From: Tyler Retzlaff @ 2024-04-15 21:32 UTC (permalink / raw)
  To: dev; +Cc: Harry van Haaren, Remy Horton, Reshma Pattan, Tyler Retzlaff, stable

Add missing f suffix to floating point literal to avoid warning about
truncation from double to float.

Fixes: 5cd3cac9ed22 ("latency: added new library for latency stats")
Cc: reshma.pattan@intel.com
Cc: stable@dpdk.org

Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
---
 lib/latencystats/rte_latencystats.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/latencystats/rte_latencystats.c b/lib/latencystats/rte_latencystats.c
index 4ea9b0d..cae4b50 100644
--- a/lib/latencystats/rte_latencystats.c
+++ b/lib/latencystats/rte_latencystats.c
@@ -166,7 +166,7 @@ struct latency_stats_nameoff {
 	 * a constant smoothing factor between 0 and 1. The value
 	 * is used below for measuring average latency.
 	 */
-	const float alpha = 0.2;
+	const float alpha = 0.2f;
 
 	now = rte_rdtsc();
 	for (i = 0; i < nb_pkts; i++) {
-- 
1.8.3.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] latencystats: fix missing f suffix on literal float
  2024-04-15 21:32 [PATCH] latencystats: fix missing f suffix on literal float Tyler Retzlaff
@ 2024-04-15 22:17 ` Stephen Hemminger
  2024-04-15 23:14   ` Tyler Retzlaff
  0 siblings, 1 reply; 4+ messages in thread
From: Stephen Hemminger @ 2024-04-15 22:17 UTC (permalink / raw)
  To: Tyler Retzlaff; +Cc: dev, Harry van Haaren, Remy Horton, Reshma Pattan, stable

On Mon, 15 Apr 2024 14:32:26 -0700
Tyler Retzlaff <roretzla@linux.microsoft.com> wrote:

> Add missing f suffix to floating point literal to avoid warning about
> truncation from double to float.
> 
> Fixes: 5cd3cac9ed22 ("latency: added new library for latency stats")
> Cc: reshma.pattan@intel.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> ---
>  lib/latencystats/rte_latencystats.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/latencystats/rte_latencystats.c b/lib/latencystats/rte_latencystats.c
> index 4ea9b0d..cae4b50 100644
> --- a/lib/latencystats/rte_latencystats.c
> +++ b/lib/latencystats/rte_latencystats.c
> @@ -166,7 +166,7 @@ struct latency_stats_nameoff {
>  	 * a constant smoothing factor between 0 and 1. The value
>  	 * is used below for measuring average latency.
>  	 */
> -	const float alpha = 0.2;
> +	const float alpha = 0.2f;
>  
>  	now = rte_rdtsc();
>  	for (i = 0; i < nb_pkts; i++) {

The use of floating point in fast path here is unnecessary.
Even without doing the full per-core values, this could just change
to an alpha of .25 and use fast fixed point math.


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] latencystats: fix missing f suffix on literal float
  2024-04-15 22:17 ` Stephen Hemminger
@ 2024-04-15 23:14   ` Tyler Retzlaff
  2024-05-29 14:38     ` Thomas Monjalon
  0 siblings, 1 reply; 4+ messages in thread
From: Tyler Retzlaff @ 2024-04-15 23:14 UTC (permalink / raw)
  To: Stephen Hemminger
  Cc: dev, Harry van Haaren, Remy Horton, Reshma Pattan, stable

On Mon, Apr 15, 2024 at 03:17:38PM -0700, Stephen Hemminger wrote:
> On Mon, 15 Apr 2024 14:32:26 -0700
> Tyler Retzlaff <roretzla@linux.microsoft.com> wrote:
> 
> > Add missing f suffix to floating point literal to avoid warning about
> > truncation from double to float.
> > 
> > Fixes: 5cd3cac9ed22 ("latency: added new library for latency stats")
> > Cc: reshma.pattan@intel.com
> > Cc: stable@dpdk.org
> > 
> > Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> > ---
> >  lib/latencystats/rte_latencystats.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/lib/latencystats/rte_latencystats.c b/lib/latencystats/rte_latencystats.c
> > index 4ea9b0d..cae4b50 100644
> > --- a/lib/latencystats/rte_latencystats.c
> > +++ b/lib/latencystats/rte_latencystats.c
> > @@ -166,7 +166,7 @@ struct latency_stats_nameoff {
> >  	 * a constant smoothing factor between 0 and 1. The value
> >  	 * is used below for measuring average latency.
> >  	 */
> > -	const float alpha = 0.2;
> > +	const float alpha = 0.2f;
> >  
> >  	now = rte_rdtsc();
> >  	for (i = 0; i < nb_pkts; i++) {
> 
> The use of floating point in fast path here is unnecessary.
> Even without doing the full per-core values, this could just change
> to an alpha of .25 and use fast fixed point math.

agree, though my thoughts are make this code correct optimization is for
the maintainer. if they submit an alternate series i can withdraw this
patch. otherwise i think we should take it as-is.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] latencystats: fix missing f suffix on literal float
  2024-04-15 23:14   ` Tyler Retzlaff
@ 2024-05-29 14:38     ` Thomas Monjalon
  0 siblings, 0 replies; 4+ messages in thread
From: Thomas Monjalon @ 2024-05-29 14:38 UTC (permalink / raw)
  To: Tyler Retzlaff
  Cc: Stephen Hemminger, dev, Harry van Haaren, Remy Horton,
	Reshma Pattan, stable

16/04/2024 01:14, Tyler Retzlaff:
> On Mon, Apr 15, 2024 at 03:17:38PM -0700, Stephen Hemminger wrote:
> > On Mon, 15 Apr 2024 14:32:26 -0700
> > Tyler Retzlaff <roretzla@linux.microsoft.com> wrote:
> > 
> > > Add missing f suffix to floating point literal to avoid warning about
> > > truncation from double to float.
> > > 
> > > Fixes: 5cd3cac9ed22 ("latency: added new library for latency stats")
> > > Cc: reshma.pattan@intel.com
> > > Cc: stable@dpdk.org
> > > 
> > > Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> > > ---
> > > -	const float alpha = 0.2;
> > > +	const float alpha = 0.2f;
> > 
> > The use of floating point in fast path here is unnecessary.
> > Even without doing the full per-core values, this could just change
> > to an alpha of .25 and use fast fixed point math.
> 
> agree, though my thoughts are make this code correct optimization is for
> the maintainer. if they submit an alternate series i can withdraw this
> patch. otherwise i think we should take it as-is.

OK to fix build warning now.

Applied, thanks.




^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2024-05-29 14:39 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-04-15 21:32 [PATCH] latencystats: fix missing f suffix on literal float Tyler Retzlaff
2024-04-15 22:17 ` Stephen Hemminger
2024-04-15 23:14   ` Tyler Retzlaff
2024-05-29 14:38     ` Thomas Monjalon

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).