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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 BAB5FC433F5 for ; Mon, 6 Sep 2021 12:11:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 79A0E60C3E for ; Mon, 6 Sep 2021 12:11:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 79A0E60C3E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id E98706B0071; Mon, 6 Sep 2021 08:11:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E47EE6B0072; Mon, 6 Sep 2021 08:11:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D361B900002; Mon, 6 Sep 2021 08:11:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0204.hostedemail.com [216.40.44.204]) by kanga.kvack.org (Postfix) with ESMTP id C1DC76B0071 for ; Mon, 6 Sep 2021 08:11:00 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 7BB9A256FC for ; Mon, 6 Sep 2021 12:11:00 +0000 (UTC) X-FDA: 78557032680.29.23C2234 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id 3FA8530000A8 for ; Mon, 6 Sep 2021 12:11:00 +0000 (UTC) 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> Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=ufiQMk8b; spf=none (imf08.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 3FA8530000A8 X-Stat-Signature: c3edimtcys63rf733s44dwy5w88awngq X-HE-Tag: 1630930260-300705 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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.