From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by sourceware.org (Postfix) with ESMTPS id DB3AA385DC1C for ; Fri, 1 May 2020 04:22:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org DB3AA385DC1C Received: by mail-pg1-x52b.google.com with SMTP id r4so4073467pgg.4 for ; Thu, 30 Apr 2020 21:22:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=5ae+KESQNMn2cWmzee4r6dOYcLvVwC202/tOqT4Y0Qk=; b=coLyQUd02G1sQ2PkdOThg8JSHONXXPhBKOfj0UHeQAPfGWpwQQLrsQDmVdtkzZsBYo SvlqisWUiIhJ+UoSmR0Q8zPx8PNDMvTlfxbbYL+A1yxZJ30kWrmwOT7EX00UhWzG5kW9 3lsr3V7Nuq8Kjmktg4d1zcFqP1ryttX+QktywcjrP5XWr7UiL5YgepfVo7/a9s9PUoIz H0f03sHrXeUr+1FZvyY3A50IIv3JQjK/aMuc+XgcPHW63v/TMXi8N03LpHJpyki86mNq lYp42iIMPKnu9p8AJ+JC4MO40e/zi9wSOTUPZtF18vFCJ5fmDXhUvwj5bbLwZWGFLKeL cBcQ== X-Gm-Message-State: AGi0PubFJ5tBjQZUbnVIth/W4u/66ewlGXUPh44lCz2ne2k6e4ID3ZbO mF9SLv56FhwS0WopPsIzHz4RPFzgs1M= X-Google-Smtp-Source: APiQypKvs7aiN8tAJWsNkaKRw4XEUlPuVCChb/CaD+9ud39CoXUysH96KTbNgJeXCGrASLWAHxD0Uw== X-Received: by 2002:a63:cf4d:: with SMTP id b13mr2466845pgj.32.1588306931087; Thu, 30 Apr 2020 21:22:11 -0700 (PDT) Received: from bubble.grove.modra.org (158.106.96.58.static.exetel.com.au. [58.96.106.158]) by smtp.gmail.com with ESMTPSA id b3sm1004868pga.48.2020.04.30.21.22.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Apr 2020 21:22:10 -0700 (PDT) Received: by bubble.grove.modra.org (Postfix, from userid 1000) id 7CFB388A78; Fri, 1 May 2020 13:52:05 +0930 (ACST) Date: Fri, 1 May 2020 13:52:05 +0930 From: Alan Modra To: Fangrui Song Cc: Haim Shimonovich , "binutils@sourceware.org" Subject: Re: objdump very long run time when using -D -z flags Message-ID: <20200501042205.GC25855@bubble.grove.modra.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Spam-Status: No, score=-12.3 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: binutils@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Binutils mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 May 2020 04:22:13 -0000 On Thu, Apr 30, 2020 at 06:22:11PM -0700, Fangrui Song wrote: > This just hides the problem. That isn't true. > -z is still going to be slow. Well, yes, because objdump is going to be showing many instructions. > To avoid > the quadratic behavior, we should increase the address by at least `z` > if we have scanned `z` zeros. What quadratic behaviour related to blocks of zeros? With -z we now won't scan, and without -z the entire block (or almost) is consumed. -- Alan Modra Australia Development Lab, IBM