linux-kernel - Re: [RFC][PATCH 09/16] objtool: Optimize find_symbol_*() and read

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Message-ID: <20200315164137.cni4vswi4wyl33s6@treble>
Date:   Sun, 15 Mar 2020 11:41:37 -0500
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     tglx@...utronix.de, linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [RFC][PATCH 09/16] objtool: Optimize find_symbol_*() and
 read_symbols()

On Thu, Mar 12, 2020 at 02:41:16PM +0100, Peter Zijlstra wrote:
>  struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset)
>  {
> -	struct symbol *sym;
> +	struct rb_node *node;
>  
> -	list_for_each_entry(sym, &sec->symbol_list, list)
> -		if (sym->type != STT_SECTION &&
> -		    sym->offset == offset)
> -			return sym;
> +	rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
> +		struct symbol *s = rb_entry(node, struct symbol, node);
> +
> +		if (s->offset != offset)
> +			continue;
> +
> +		if (s->type != STT_SECTION)
> +			return s;
> +	}

Can be simplified to:

		if (s->offset == offset && s->type != STT_SECTION)
			return s;

-- 
Josh