From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: "Yigit, Ferruh" <ferruh.yigit@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] igb_uio: use macros for array size calculation
Date: Thu, 3 Mar 2016 17:45:46 +0000 [thread overview]
Message-ID: <2601191342CEEE43887BDE71AB97725836B16008@irsmsx105.ger.corp.intel.com> (raw)
In-Reply-To: <56D875C3.20507@intel.com>
> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Thursday, March 03, 2016 5:35 PM
> To: Ananyev, Konstantin; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] igb_uio: use macros for array size calculation
>
> On 3/3/2016 5:25 PM, Ananyev, Konstantin wrote:
> >
> >
> >> -----Original Message-----
> >> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ferruh Yigit
> >> Sent: Thursday, March 03, 2016 5:08 PM
> >> To: dev@dpdk.org
> >> Subject: [dpdk-dev] [PATCH] igb_uio: use macros for array size calculation
> >>
> >> Minor code cleanup.
> >> Remove array size calculations and remove unnecessary assignment.
> >>
> >> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> >> ---
> >> lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 8 ++++----
> >> 1 file changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> >> index 3374e44..563c57b 100644
> >> --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> >> +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> >> @@ -58,7 +58,7 @@ struct rte_uio_pci_dev {
> >> enum rte_intr_mode mode;
> >> };
> >>
> >> -static char *intr_mode = NULL;
> >> +static char *intr_mode;
> >> static enum rte_intr_mode igbuio_intr_mode_preferred = RTE_INTR_MODE_MSIX;
> >>
> >> /* sriov sysfs */
> >> @@ -332,7 +332,7 @@ igbuio_pci_setup_iomem(struct pci_dev *dev, struct uio_info *info,
> >> unsigned long addr, len;
> >> void *internal_addr;
> >>
> >> - if (sizeof(info->mem) / sizeof(info->mem[0]) <= n)
> >> + if (n >= MAX_UIO_MAPS)
> >
> > Why using hardcoded value is better than sizeof()?
> > As I can see below there is a macro ARRAY_SIZE, why not to use it here then?
>
> Both are valid, but in uio (uio_driver.h) "mem" array defined as:
> struct uio_mem mem[MAX_UIO_MAPS];
Yep, so if both are valid, why to change it a the first place? :)
>
> So we already know the size of the array, and it is exposed to us, why
> need to calculate. Is there any benefit of calculating it?
if in future definition of the mem[] would change to let say:
struct uio_mem mem[X]
your code would still be valid, and no need to update it.
Konstantin
>
> Thanks,
> ferruh
next prev parent reply other threads:[~2016-03-03 17:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-03 17:08 [dpdk-dev] [PATCH] igb_uio: cast private data to correct struct type Ferruh Yigit
2016-03-03 17:08 ` [dpdk-dev] [PATCH] igb_uio: use macros for array size calculation Ferruh Yigit
2016-03-03 17:25 ` Ananyev, Konstantin
2016-03-03 17:34 ` Ferruh Yigit
2016-03-03 17:45 ` Ananyev, Konstantin [this message]
2016-03-03 18:16 ` Ferruh Yigit
2016-03-04 11:21 ` [dpdk-dev] [PATCH v2] " Ferruh Yigit
2016-03-04 11:43 ` Ananyev, Konstantin
2016-03-07 22:30 ` Thomas Monjalon
2016-03-04 13:17 ` [dpdk-dev] [PATCH] igb_uio: cast private data to correct struct type Ananyev, Konstantin
2016-03-07 22:29 ` Thomas Monjalon
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