[dpdk-dev] [PATCH] eal: fix parsing of argument of option --lcores

[Dai, Wei]

Hi Bynes
Thanks for your feedback.

> -----Original Message-----
> From: bynes adam [mailto:adambynes at outlook.com]
> Sent: Friday, July 22, 2016 4:45 AM
> To: Dai, Wei <wei.dai at intel.com>
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] eal: fix parsing of argument of option --lcores
> 
> On Thu, Jul 21, 2016 at 02:03:38PM +0800, Wei Dai wrote:
> Hi Wei,
> > The '-' in lcores set overrides cpu set of following lcore set in the
> > argument of EAL option --lcores.
> >
> > Fixes: 53e54bf81700 ("eal: new option --lcores for cpu assignment")
> >
> > Signed-off-by: Wei Dai <wei.dai at intel.com>
> > ---
> >  lib/librte_eal/common/eal_common_options.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/lib/librte_eal/common/eal_common_options.c
> > b/lib/librte_eal/common/eal_common_options.c
> > index 0a594d7..96eb1a9 100644
> > --- a/lib/librte_eal/common/eal_common_options.c
> > +++ b/lib/librte_eal/common/eal_common_options.c
> > @@ -563,6 +563,7 @@ convert_to_cpuset(rte_cpuset_t *cpusetp,
> >   * lcores, cpus could be a single digit/range or a group.
> >   * '(' and ')' are necessary if it's a group.
> >   * If not supply '@cpus', the value of cpus uses the same as lcores.
> > + * The 'a-b' in lcores not within '(' and ')' means a,a+1,...,b-1,b .
> this description is not very clear, a-b and (a-b) are both the same meaning.
> may be need a table for comparison
> a-b@(c-d)
> a-b at c-d
> (a-b)@c-d
> (a-b)@(c-d)
> all the above I believe are the same
> only the following two cases:
> a-b,
> (a-b),

With --lcores '0-3 at 12-15', eal_parse_cores( ) will fail because eal_parse_set( )
find the next char after lcore set is '@' and is not ',' or '\0'.
So the bug in eal_parse_set( ) should be fixed. 
A patch v3 will be provided.
After fixing, I test it with --lcores '0-3 at 12-15, 4-7@(8-11),  (8-11)@4-7, (12-15)@(0-3), 16-19, (20-23) '
It works well.

Thanks
Wei

> so the key point here is the @ and (), not only @
> >   * e.g. '1,2@(5-7),(3-5)@(0,2),(0,6),7-8' means start 9 EAL thread as below
> >   *   lcore 0 runs on cpuset 0x41 (cpu 0,6)
> >   *   lcore 1 runs on cpuset 0x2 (cpu 1)
> > @@ -571,6 +572,15 @@ convert_to_cpuset(rte_cpuset_t *cpusetp,
> >   *   lcore 6 runs on cpuset 0x41 (cpu 0,6)
> >   *   lcore 7 runs on cpuset 0x80 (cpu 7)
> >   *   lcore 8 runs on cpuset 0x100 (cpu 8)
> > + * e.g. '0-2,(3-5)@(3,4),6@(5,6),7@(5-7)'means start 8 EAL threads as
> below
> > + *   lcore 0 runs on cpuset 0x1 (cpu 0)
> > + *   lcore 1 runs on cpuset 0x2 (cpu 1)
> > + *   lcore 2 runs on cpuset ox4 (cpu 2)
> > + *   lcore 3,4,5 runs on cpuset 0x18 (cpu 3,4)
> > + *   lcore 6 runs on cpuset 0x60 (cpu 5,6)
> > + *   lcore 7 runs on cpuset 0xe0 (cpu 5,6,7)
> > + * The second case is used to test bugfix for lflags not be cleared
> > + after use
> you can put this sentance and description into the commit log I don't think you
> should put bugfix description in comments here.
> > + */
> >   */
> >  static int
> >  eal_parse_lcores(const char *lcores)
> > @@ -679,6 +689,8 @@ eal_parse_lcores(const char *lcores)
> >  				   sizeof(rte_cpuset_t));
> >  		}
> >
> > +		lflags = 0;
> > +
> >  		lcores = end + 1;
> >  	} while (*end != '\0');
> >
> > --
> > 2.5.5
> Adam Bynes