From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B733C433EF for ; Mon, 6 Sep 2021 12:10:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D905860F45 for ; Mon, 6 Sep 2021 12:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241737AbhIFMLv (ORCPT ); Mon, 6 Sep 2021 08:11:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239993AbhIFMLt (ORCPT ); Mon, 6 Sep 2021 08:11:49 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F1FFC061575; Mon, 6 Sep 2021 05:10:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=rCmh1KfC0hUsWI8m+mOwABNgKJfWxkdKYiq+H56M0BI=; b=ufiQMk8bZfkG/iYyy5zcmQBoC6 G+OXykPBnP9uwZNhQ1dlHMEu9C1VGHgnCkEws2jkLqMEDDI/8Xk6ZK1q65QvTfIhaAME0TzSA4+ZM yRHoKXzkKUqvyP++yPGRrqfqavRiASeddqYMprOSu2tJ7fYBYskpZX1ro5X8j/yP7o4z+XSVEa2+w kzGnLSolTb+z7hUg35HtLr/0bUzaBrUcHLP/VsZCeOt62g3ZLH2r7U0fHN4UNMTQnN0eNUC0+3eAJ V38lTXHRSj33yW5ZEtyGhN+kerZpCW3GU84X/Gge80mrApUsrt05PzLV81lF6gx7wGZvsU0TqHPAh oUmS4bCA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mNDRC-006vSd-In; Mon, 06 Sep 2021 12:09:36 +0000 Date: Mon, 6 Sep 2021 13:09:22 +0100 From: Matthew Wilcox To: Huang Shijie Cc: viro@zeniv.linux.org.uk, akpm@linux-foundation.org, jlayton@kernel.org, bfields@fieldses.org, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, song.bao.hua@hisilicon.com, patches@amperecomputing.com, zwang@amperecomputing.com Subject: Re: [RFC PATCH] fs/exec: Add the support for ELF program's NUMA replication Message-ID: References: <20210906161613.4249-1-shijie@os.amperecomputing.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210906161613.4249-1-shijie@os.amperecomputing.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 06, 2021 at 04:16:13PM +0000, Huang Shijie wrote: > This patch adds AT_NUMA_REPLICATION for execveat(). > > If this flag is set, the kernel will trigger COW(copy on write) > on the mmapped ELF binary. So the program will have a copied-page > on its NUMA node, even if the original page in page cache is > on other NUMA nodes. This does absolutely nothing for programs which run on multiple NUMA nodes at the same time. Also, I dislike the abuse of the term "COW" for this. It's COF -- Copy On Fault.