Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932180AbWESCXQ (ORCPT ); Thu, 18 May 2006 22:23:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932182AbWESCXQ (ORCPT ); Thu, 18 May 2006 22:23:16 -0400 Received: from nf-out-0910.google.com ([64.233.182.185]:61901 "EHLO nf-out-0910.google.com") by vger.kernel.org with ESMTP id S932180AbWESCXP convert rfc822-to-8bit (ORCPT ); Thu, 18 May 2006 22:23:15 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=MObCSty5XVsjsYsjxVCuPj0UT8Mq/d9zSyQfklkcTpXZyOVO0kSJm/EuExNF50xhBSzcDoL0u4WIqyWwweaJlOLTrIpJf5tKZZ3QNhgHVaYoDgVIH6TXaSTh2rEefonruxfG2DzHx7fsEWdXm9ESmFME8fiWnFDKudaAFGUUdWM= Message-ID: Date: Thu, 18 May 2006 19:23:13 -0700 From: "Ulrich Drepper" To: "Renzo Davoli" Subject: Re: [PATCH] 2-ptrace_multi Cc: "Andi Kleen" , osd@cs.unibo.it, linux-kernel@vger.kernel.org In-Reply-To: <20060518211321.GC6806@cs.unibo.it> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <20060518155337.GA17498@cs.unibo.it> <20060518155848.GC17498@cs.unibo.it> <20060518211321.GC6806@cs.unibo.it> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 601 Lines: 12 On 5/18/06, Renzo Davoli wrote: > e.g. To virtualize a write you'd have to call PTRACE_PEEKDATA for each > word of the buffer, very many hundreds cycles lost. No, this is not how programs should do it. Just open /proc/PID/mem and use pread() with an offset corresponding to the address. Now, repeat your timings using this technique. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/