Date: Mon, 14 Jun 2010 11:52:49 +1000 From: Lawrence Stewart <lstewart@freebsd.org> To: Pawel Jakub Dawidek <pjd@FreeBSD.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r209119 - head/sys/sys Message-ID: <4C158B71.205@freebsd.org> In-Reply-To: <20100613101025.GD1320@garage.freebsd.pl> References: <201006130239.o5D2du3m086332@svn.freebsd.org> <20100613101025.GD1320@garage.freebsd.pl>
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On 06/13/10 20:10, Pawel Jakub Dawidek wrote:
> On Sun, Jun 13, 2010 at 02:39:55AM +0000, Lawrence Stewart wrote:
[snip]
>>
>> Modified: head/sys/sys/pcpu.h
>> ==============================================================================
>> --- head/sys/sys/pcpu.h Sun Jun 13 01:27:29 2010 (r209118)
>> +++ head/sys/sys/pcpu.h Sun Jun 13 02:39:55 2010 (r209119)
>> @@ -106,6 +106,17 @@ extern uintptr_t dpcpu_off[];
>> #define DPCPU_ID_GET(i, n) (*DPCPU_ID_PTR(i, n))
>> #define DPCPU_ID_SET(i, n, v) (*DPCPU_ID_PTR(i, n) = v)
>>
>> +/*
>> + * Utility macros.
>> + */
>> +#define DPCPU_SUM(n, var, sum) \
>> +do { \
>> + (sum) = 0; \
>> + u_int i; \
>> + CPU_FOREACH(i) \
>> + (sum) += (DPCPU_ID_PTR(i, n))->var; \
>> +} while (0)
>
> I'd suggest first swapping variable declaration and '(sum) = 0;'.
> Also using 'i' as a counter in macro can easly lead to name collision.
> If you need to do it, I'd suggest '_i' or something.
Given that the DPCPU variable name space is flat and variable names have
to be unique, perhaps something like the following would address the
concerns raised?
#define DPCPU_SUM(n, var, sum) \
do { \
u_int _##n##_i; \
(sum) = 0; \
CPU_FOREACH(_##n##_i) \
(sum) += (DPCPU_ID_PTR(_##n##_i, n))->var; \
} while (0)
Cheers,
Lawrence
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