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Subject: Re: [PATCH 1/2] ia64: Use ARRAY_SIZE to replace its implementation
From:   Joe Perches <golf@perches.com>
To:     zhong jiang <zhongjiang@huawei.com>, tony.luck@intel.com,
        fenghua.yu@intel.com, benh@kernel.crashing.org, paulus@samba.org,
        mpe@ellerman.id.au, oleg@redhat.com, rppt@linux.vnet.ibm.com,
        dhowells@redhat.com, akpm@linux-foundation.org,
        viro@zeniv.linux.org.uk
Cc:     linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org
Date:   Mon, 13 Aug 2018 21:45:05 -0700
In-Reply-To: <1534214814-9043-2-git-send-email-zhongjiang@huawei.com>
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         <1534214814-9043-2-git-send-email-zhongjiang@huawei.com>
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On Tue, 2018-08-14 at 10:46 +0800, zhong jiang wrote:
> We prefer to ARRAY_SIZE rather than duplicating its implementation.
> So just replace it.
[]
> diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
[]
> @@ -4645,7 +4645,7 @@ static char *pfmfs_dname(struct dentry *dentry, char *buffer, int buflen)
>  /* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
>  /* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
>  };
> -#define PFM_CMD_COUNT	(sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
> +#define PFM_CMD_COUNT	ARRAY_SIZE(pfm_cmd_tab)

Better would be to remove the #define altogether and change
the one place where it's used to ARRAY_SIZE(...)
---
 arch/ia64/kernel/perfmon.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index a9d4dc6c0427..08ece2c7b6e1 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -4645,7 +4645,6 @@ static pfm_cmd_desc_t pfm_cmd_tab[]={
 /* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
 /* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
 };
-#define PFM_CMD_COUNT	(sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
 
 static int
 pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
@@ -4770,7 +4769,7 @@ sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
 	 */
 	if (unlikely(pmu_conf == NULL)) return -ENOSYS;
 
-	if (unlikely(cmd < 0 || cmd >= PFM_CMD_COUNT)) {
+	if (unlikely(cmd < 0 || cmd >= ARRAY_SIZE(pfm_cmd_tab)) {
 		DPRINT(("invalid cmd=%d\n", cmd));
 		return -EINVAL;
 	}