[PATCH] event: fix warning from useless snprintf

[Stephen Hemminger]

On Wed, 24 Apr 2024 17:12:39 +0000
"Van Haaren, Harry" <harry.van.haaren at intel.com> wrote:

> > ________________________________________
> > From: Stephen Hemminger <stephen at networkplumber.org>
> > Sent: Wednesday, April 24, 2024 5:13 PM
> > To: Van Haaren, Harry
> > Cc: dev at dpdk.org; Richardson, Bruce; Jerin Jacob
> > Subject: Re: [PATCH] event: fix warning from useless snprintf
> > 
> > On Wed, 24 Apr 2024 08:45:52 +0000
> > "Van Haaren, Harry" <harry.van.haaren at intel.com> wrote:
> >   
> > > > From: Stephen Hemminger <stephen at networkplumber.org>
> > > > Sent: Wednesday, April 24, 2024 4:45 AM
> > > > To: dev at dpdk.org
> > > > Cc: Richardson, Bruce; Stephen Hemminger; Van Haaren, Harry; Jerin Jacob
> > > > Subject: [PATCH] event: fix warning from useless snprintf
> > > >
> > > > With Gcc-14, this warning is generated:
> > > > ../drivers/event/sw/sw_evdev.c:263:3: warning: 'snprintf' will always be truncated;
> > > >     specified size is 12, but format string expands to at least 13 [-Wformat-truncation]
> > > >   263 |                 snprintf(buf, sizeof(buf), "sw%d_iq_%d_rob", dev_id, i);
> > > >       |                 ^
> > > >
> > > > Yet the whole printf to the buf is unnecessary. The type string argument
> > > > has never been implemented, and should just be NULL.  Removing the
> > > > unnecessary snprintf, then means IQ_ROB_NAMESIZE can be removed.  
> > >
> > > I understand that today the "type" value isn't implemented, but across the DPDK codebase it
> > > seems like others are filling in "type" to be some debug-useful name/string. If it was added
> > > in future it'd be nice to have the ROB/IQ memory identified by name, like the rest of DPDK components.  
> > 
> > No, don't bother. This is a case of https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it  
> 
> I agree that YAGNI perhaps applied when designing the APIs, but the "type" parameter is there now...
> Should we add a guidance of "when reworking code, always pass NULL as the type parameter to rte_malloc functions" somewhere in the programmers guide, to align community with this "pass NULL for type" initiative?
> 
> <snip>
> 
> Acked-by: Harry van Haaren <harry.van.haaren at intel.com>
> 

Did look into Mi-Malloc https://github.com/microsoft/mimalloc
it is fast and more complete and good work with huge pages.
The way to handle tagging allocations having the library automatically handle it
based on the place allocation is called from. Having user do it is not that helpful.