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Date:   Mon, 28 Oct 2019 10:20:45 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Wei Yang <richardw.yang@linux.intel.com>
Cc:     akpm@linux-foundation.org, walken@google.com, dbueso@suse.de,
        tglx@linutronix.de, linux-kernel@vger.kernel.org
Subject: Re: [Patch v2 1/2] lib/rbtree: set successor's parent unconditionally
Message-ID: <20191028092045.GC4114@hirez.programming.kicks-ass.net>
References: <20191028021442.5450-1-richardw.yang@linux.intel.com>
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On Mon, Oct 28, 2019 at 10:14:41AM +0800, Wei Yang wrote:
> Both in Case 2 and 3, we exchange n and s. This mean no matter whether
> child2 is NULL or not, successor's parent should be assigned to node's.
> 
> This patch takes this step out to make it explicit and reduce the
> ambiguity.
> 
> Besides, this step reduces some symbol size like rb_erase().
> 
>    KERN_CONFIG       upstream       patched
>    OPT_FOR_PERF      877            870
>    OPT_FOR_SIZE      635            621
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>