[dpdk-dev] [PATCH v2 1/2] eal: remove redundant codes to parse --lcores

[Dai, Wei]

Hi, Adam & Ananyev
Thanks for your feedback.

> -----Original Message-----
> From: Adam Bynes [mailto:adambynes at outlook.com]
> Sent: Wednesday, July 27, 2016 1:36 AM
> To: Dai, Wei <wei.dai at intel.com>; Ananyev, Konstantin
> <konstantin.ananyev at intel.com>
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v2 1/2] eal: remove redundant codes to parse
> --lcores
> 
> On Tue, Jul 26, 2016 at 11:51:57AM +0000, Ananyev, Konstantin wrote:
> >
> >
> hi Wei,
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Wei Dai
> > > Sent: Tuesday, July 26, 2016 10:52 AM
> > > To: dev at dpdk.org
> > > Cc: Dai, Wei <wei.dai at intel.com>
> > > Subject: [dpdk-dev] [PATCH v2 1/2] eal: remove redundant codes to parse
> --lcores
> > >
> > > local variable i is not referred by other codes in the function
> eal_parse_lcores( ), so it can be removed.
> > >
> > > Signed-off-by: Wei Dai <wei.dai at intel.com>
> > > ---
> > >  lib/librte_eal/common/eal_common_options.c | 4 ----
> > >  1 file changed, 4 deletions(-)
> > >
> > > diff --git a/lib/librte_eal/common/eal_common_options.c
> b/lib/librte_eal/common/eal_common_options.c
> > > index 481c732..c5bf98c 100644
> > > --- a/lib/librte_eal/common/eal_common_options.c
> > > +++ b/lib/librte_eal/common/eal_common_options.c
> > > @@ -578,7 +578,6 @@ eal_parse_lcores(const char *lcores)
> > >  	struct rte_config *cfg = rte_eal_get_configuration();
> > >  	static uint16_t set[RTE_MAX_LCORE];
> > >  	unsigned idx = 0;
> > > -	int i;
> > >  	unsigned count = 0;
> > >  	const char *lcore_start = NULL;
> > >  	const char *end = NULL;
> > > @@ -593,9 +592,6 @@ eal_parse_lcores(const char *lcores)
> > >  	/* Remove all blank characters ahead and after */
> > >  	while (isblank(*lcores))
> > >  		lcores++;
> > > -	i = strlen(lcores);
> > > -	while ((i > 0) && isblank(lcores[i - 1]))
> > > -		i--;
> >
> > I suppose originally it meant to do something  like that:
> > while ((i > 0) && isblank(lcores[i - 1]))
> > 	lcores[i--] = 0;
> totally agreed Konstantin, need to add lcore[i--] = '\0'
> 
> >
> > to get rid of blank characters at the end of the line, no?
> > Konstantin

The tail blank is not necessary to be removed from lcores here for following reasons:
1. The tail blanks can also be swallowed later in function eal_parse_set( ) 
  by "while (isblank(*end)) end++". And such operation/sentence also
  deal with blanks in the middle of arguments (for example: blank before
  - and after (7,8) in '0   -2    ,(3   - 6)@(3-6),7@(7-8)     ,8@(8-10)      '), 
  so above removal of blank is redundant.
  By the way, with --lcores '(0-3)@(0-3), (4-5)@(4-5)    ', I also find a new bug.
  After processing cpu set (4-5), the variable end in eal_parse_lcores doesn't point t
  ',' or '\0',  so this function return an error.
  The tail blank after cpu set (4-5) still need to be swallowed. 
  The patch v3 will be removed.eal

2. if let lcores[i--] = 0 here, due to type of input argument lcores (const char *), 
  building will fail. And if the type is changed to char *, the type of input argument of
  several other function also need to be changed. So according to above reason 1, it
  is not need to change the type.

Thanks
Wei Dai 

> >
> > >
> > >  	CPU_ZERO(&cpuset);
> > >
> > > --
> > > 2.5.5
> Adam Bynes