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

[Thomas Monjalon <thomas.monjalon@6wind.com>]

Hi,

2016-07-21 14:03, Wei Dai:
> 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@intel.com>

Thanks for the catch!

> --- 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 .

It also a range when inside a group.
The difference is the mapping to the cpus.
I think this new comment brings more confusion. Better to skip.

>   * 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
> + */
>   */

Please do not add a second example just to show how to test your fix.

> @@ -679,6 +689,8 @@ eal_parse_lcores(const char *lcores)
>  				   sizeof(rte_cpuset_t));
>  		}
>  
> +		lflags = 0;
> +
>  		lcores = end + 1;
>  	} while (*end != '\0');

It would have more sense to init lflags at the beginning of the loop
and replace
	int lflags = 0;
by
	int lflags;