Re: [PATCH v2 1/3] virsh: fix memtune to also accept 0 as valid value

[Peter Krempa <pkrempa@xxxxxxxxxx>]

On Thu, Mar 05, 2015 at 16:10:28 +0100, Pavel Hrdina wrote:
> Signed-off-by: Pavel Hrdina <phrdina@xxxxxxxxxx>

Commit message is still too sparse ...

> ---
>  tools/virsh-domain.c | 83 ++++++++++++++++++++++++----------------------------
>  1 file changed, 38 insertions(+), 45 deletions(-)
> 
> diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
> index 55c269c..3836a1b 100644
> --- a/tools/virsh-domain.c
> +++ b/tools/virsh-domain.c
> @@ -8255,6 +8255,22 @@ static const vshCmdOptDef opts_memtune[] = {
>      {.name = NULL}
>  };
>  
> +/**
> + * vshMemtuneGetSize
> + *
> + * @cmd: pointer to vshCmd
> + * @name: name of a parameter for which we would like to get a value
> + * @value: pointer to variable where the value will be stored
> + *
> + * This function will parse virsh command line in order to load a value of
> + * specified parameter. If the value is -1 we will handle it as unlimited and
> + * use VIR_DOMAIN_MEMORY_PARAM_UNLIMITED instead.
> + *
> + * Returns:
> + *  >0 if option found and valid (@value updated)
> + *  0 if option not found and not required (@value untouched)
> + *  <0 in all other cases (@value untouched)

The last one is not true. If the scaling function fails @value is
touched but the function returns -1. I'd drop the statements altogether.

> + */
>  static int
>  vshMemtuneGetSize(const vshCmd *cmd, const char *name, long long *value)
>  {
> @@ -8276,7 +8292,7 @@ vshMemtuneGetSize(const vshCmd *cmd, const char *name, long long *value)
>      if (virScaleInteger(&tmp, end, 1024, LLONG_MAX) < 0)
>          return -1;
>      *value = VIR_DIV_UP(tmp, 1024);
> -    return 0;
> +    return 1;
>  }
>  
>  static bool
> @@ -8294,6 +8310,7 @@ cmdMemtune(vshControl *ctl, const vshCmd *cmd)
>      bool current = vshCommandOptBool(cmd, "current");
>      bool config = vshCommandOptBool(cmd, "config");
>      bool live = vshCommandOptBool(cmd, "live");
> +    int rc;
>  
>      VSH_EXCLUSIVE_OPTIONS_VAR(current, live);
>      VSH_EXCLUSIVE_OPTIONS_VAR(current, config);
> @@ -8306,50 +8323,26 @@ cmdMemtune(vshControl *ctl, const vshCmd *cmd)
>      if (!(dom = vshCommandOptDomain(ctl, cmd, NULL)))
>          return false;
>  
> -    if (vshMemtuneGetSize(cmd, "hard-limit", &hard_limit) < 0 ||
> -        vshMemtuneGetSize(cmd, "soft-limit", &soft_limit) < 0 ||
> -        vshMemtuneGetSize(cmd, "swap-hard-limit", &swap_hard_limit) < 0 ||
> -        vshMemtuneGetSize(cmd, "min-guarantee", &min_guarantee) < 0) {
> -        vshError(ctl, "%s",
> -                 _("Unable to parse integer parameter"));
> -        goto cleanup;
> -    }
> -
> -    if (hard_limit) {
> -        if (hard_limit == -1)
> -            hard_limit = VIR_DOMAIN_MEMORY_PARAM_UNLIMITED;
> -        if (virTypedParamsAddULLong(&params, &nparams, &maxparams,
> -                                    VIR_DOMAIN_MEMORY_HARD_LIMIT,
> -                                    hard_limit) < 0)
> -            goto save_error;
> -    }
> -
> -    if (soft_limit) {
> -        if (soft_limit == -1)
> -            soft_limit = VIR_DOMAIN_MEMORY_PARAM_UNLIMITED;
> -        if (virTypedParamsAddULLong(&params, &nparams, &maxparams,
> -                                    VIR_DOMAIN_MEMORY_SOFT_LIMIT,
> -                                    soft_limit) < 0)
> -            goto save_error;
> -    }
> -
> -    if (swap_hard_limit) {
> -        if (swap_hard_limit == -1)
> -            swap_hard_limit = VIR_DOMAIN_MEMORY_PARAM_UNLIMITED;
> -        if (virTypedParamsAddULLong(&params, &nparams, &maxparams,
> -                                    VIR_DOMAIN_MEMORY_SWAP_HARD_LIMIT,
> -                                    swap_hard_limit) < 0)
> -            goto save_error;
> -    }
> -
> -    if (min_guarantee) {
> -        if (min_guarantee == -1)
> -            min_guarantee = VIR_DOMAIN_MEMORY_PARAM_UNLIMITED;
> -        if (virTypedParamsAddULLong(&params, &nparams, &maxparams,
> -                                    VIR_DOMAIN_MEMORY_MIN_GUARANTEE,
> -                                    min_guarantee) < 0)
> -            goto save_error;
> -    }
> +#define PARSE_MEMTUNE_PARAM(NAME, VALUE, FIELD)                             \
> +    if ((rc = vshMemtuneGetSize(cmd, NAME, &VALUE)) < 0) {                  \
> +        vshError(ctl, "%s", _("Unable to parse integer parameter 'NAME'")); \
> +        goto cleanup;                                                       \
> +    }                                                                       \
> +    if (rc == 1) {                                                          \
> +        if (virTypedParamsAddULLong(&params, &nparams, &maxparams,          \
> +                                    FIELD, VALUE) < 0)                      \
> +            goto save_error;                                                \
> +    }                                                                       \
> +
> +
> +    PARSE_MEMTUNE_PARAM("hard-limit", hard_limit, VIR_DOMAIN_MEMORY_HARD_LIMIT);
> +    PARSE_MEMTUNE_PARAM("soft-limit", soft_limit, VIR_DOMAIN_MEMORY_SOFT_LIMIT);

I just realized that the 'hard_limit', 'soft_limit' ... variables are
used just as temp variables in the macro. You could get rid of them and
use a single temp variable instead.

> +    PARSE_MEMTUNE_PARAM("swap-hard-limit", swap_hard_limit,
> +                        VIR_DOMAIN_MEMORY_SWAP_HARD_LIMIT);

Which would make these fit on one line.

> +    PARSE_MEMTUNE_PARAM("min-guarantee", min_guarantee,
> +                        VIR_DOMAIN_MEMORY_MIN_GUARANTEE);
> +
> +#undef PARSE_MEMTUNE_PARAM
>  
>      if (nparams == 0) {
>          /* get the number of memory parameters */

ACK if you drop the parenthesed section in the comment as pointed above.
The rest is not mandatory, although I'd prefer if the patch had a proper
commit message.

Peter

Attachment: signature.asc
Description: Digital signature

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list