Messages in this thread | | | Date | Mon, 12 Nov 2012 10:05:09 +0800 | From | Shan Wei <> | Subject | Re: [PATCH v3 7/9] trace: use this_cpu_ptr per-cpu helper |
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Christoph Lameter said, at 2012/11/10 4:15: > On Fri, 9 Nov 2012, Shan Wei wrote: > >> - return buffer->buffer; >> + return (char *)this_cpu_ptr(&percpu_buffer->buffer); >> } > > Add a comment to explain the cast?
typeof(&buffer) is a pointer to array of 1024 char, or char (*)[1024]. But, typeof(&buffer[0]) is a pointer to char which match the return type of get_trace_buf(). As well-known, the value of &buffer is equal to &buffer[0]. so return this_cpu_ptr(&percpu_buffer->buffer[0]) can avoid this cast.
I will submit v4 version patch which improve it.
Thanks~
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