Re: [PATCH v5] bitmap: add scan from offset function

[Volodymyr Fialko <vfialko@marvell.com>]

> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Wednesday, July 3, 2024 2:50 PM
> To: Volodymyr Fialko
> Cc: dev@dpdk.org; cristian.dumitrescu@intel.com; Jerin Jacob; Anoob Joseph
> Subject: Re: [PATCH v5] bitmap: add scan from offset function
>
> 03/07/2023 14:39, Volodymyr Fialko:
> > Currently, in the case when we search for a bit set after a particular
> > value, the bitmap has to be scanned from the beginning and
> > rte_bitmap_scan() has to be called multiple times until we hit the value.
> >
> > Add a new rte_bitmap_scan_from_offset() function to initialize scan
> > state at the given offset and perform scan, this will allow getting
> > the next set bit after certain offset within one scan call.
> >
> > Signed-off-by: Volodymyr Fialko <vfialko@marvell.com>
> > ---
> > v2:
> >  - added rte_bitmap_scan_from_offset
> > v3:
> >  - added note for internal use only for init_at function
> > v4:
> >  - marked init_at function as __rte_internal
> > v5:
> >  - removed __rte_internal due to build errors
> 
> What was the build error?
> 
> You should not add an internal function in the public header file.
> At least, it should be experimental.
> 

From our discussion in previous versions(V3, V4), It looks like we agreed to
remove both markers.

> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Monday, July 3, 2023 2:17 PM
> To: Dumitrescu, Cristian; Volodymyr Fialko
> Cc: dev@dpdk.org; Jerin Jacob Kollanukkaran; Anoob Joseph
> Subject: Re: [PATCH v3] bitmap: add scan from offset function
> 
> > ----------------------------------------------------------------------
> > 03/07/2023 12:56, Volodymyr Fialko:
> > > Since it's header-only library, there is issue with using __rte_intenal (appeared in v4).
> > 
> > What is the issue?
> 
> From V4 ci build failure(http://mails.dpdk.org/archives/test-report/2023-July/421235.html):
> 	In file included from ../examples/ipsec-secgw/event_helper.c:6:
> 	../lib/eal/include/rte_bitmap.h:645:2: error: Symbol is not public ABI
> 	        __rte_bitmap_scan_init_at(bmp, offset);
>  	       ^
> 	../lib/eal/include/rte_bitmap.h:150:1: note: from 'diagnose_if' attribute on '__rte_bitmap_scan_init_at':
> 	__rte_internal
> 	^~~~~~~~~~~~~~
> 	../lib/eal/include/rte_compat.h:42:16: note: expanded from macro '__rte_internal'	
> 	__attribute__((diagnose_if(1, "Symbol is not public ABI", "error"), \
>               		^           ~
> 	1 error generated.

> OK I see.
> So we should give up with __rte_internal for inline functions.
> As it is not supposed to be exposed to the applications,
> I think we can skip the __rte_experimental flag.

/Volodymyr