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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31120C7618B for ; Fri, 17 Mar 2023 21:58:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231192AbjCQV6j (ORCPT ); Fri, 17 Mar 2023 17:58:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230325AbjCQV6g (ORCPT ); Fri, 17 Mar 2023 17:58:36 -0400 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D10BA37B73 for ; Fri, 17 Mar 2023 14:58:32 -0700 (PDT) Received: by mail-wr1-x430.google.com with SMTP id o7so5647699wrg.5 for ; Fri, 17 Mar 2023 14:58:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679090311; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=d5Vf9hPk4TijoCslag2qu8Bydr8Y3MLZgxsiyraFWDI=; b=GesoOYtkRvZvc8UDZKdCOVv0bjs87Z0DM/cCHzjncbj1wX0MSojd2K6jf+QesOuh5Q kZCmczsOpxAvQxJ/szlpbti5EhBsTBHiB8u5bpuRmtYYcTJAjo9FTQACwgEcjoEffI13 9zI+fXO1DsSlQnmy2LnosY9x9FRHintSA5ITqXFnLW/ta0bMBArTS9ybGrRmbc3+GkLt XGPZrxMgyHGMLYdJ/0byP30lidX6IHuMG+51aEfrZVqs6+m+Q/VdSjwtAX/jaUXhoFDT bLm+KGk5Mksuz/kRewHry8LFRV6rodlbgmrXtijDCcxwKp5lCtWckhzm+U5QQwwmP9EQ 37Pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679090311; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=d5Vf9hPk4TijoCslag2qu8Bydr8Y3MLZgxsiyraFWDI=; b=c+MrdvfuNiac4kW7B/pvWCgI45Kw8ePYDKqJsuZIS+xWvZ0qo1O47muj/2Sl0TLZra 0iW1hyHaxgirzBQGJUYaKcGGnvmunbZPnztZnr15guRy87vCjPKP4OWPMR/9NOR3Xxtn o34vgEFecNclq3MT9LXSNE9niOKLZ8Dc8ckIfY3XfU+tESmVQpl9/KNUSelTwuSFH5gQ FdfeCI6m4B7OII8qW0Z/4B2myzuPiFMtSe9clxs6HJvkOEj8Co+i2i4ksAzmSoau53PM 5UfqwyVPxcUz33vh06obOgZgEt39rr3hq+4CYMtLjN0ZiSYfwTblcf6hsEQNB4tGS4fL kViQ== X-Gm-Message-State: AO0yUKWCniRaDAQV4HTmtO7NwvSu7/WA8s3RloCQuxAwc7bePyLXprI1 s+jJdeZlcPmlT/1RFhM2T90= X-Google-Smtp-Source: AK7set/0giHP1Q0iPR9xqaXyDpTJ/ztJWRNNYrWVJ0+w4kQpByF/HxcMY6MvBXLY5FhRiRmI///LxA== X-Received: by 2002:a5d:6944:0:b0:2c5:4c9d:2dab with SMTP id r4-20020a5d6944000000b002c54c9d2dabmr3807112wrw.10.1679090310797; Fri, 17 Mar 2023 14:58:30 -0700 (PDT) Received: from lucifer.home (host86-146-209-214.range86-146.btcentralplus.com. [86.146.209.214]) by smtp.googlemail.com with ESMTPSA id c9-20020a5d4cc9000000b002d21379bcabsm2849757wrt.110.2023.03.17.14.58.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Mar 2023 14:58:29 -0700 (PDT) From: Lorenzo Stoakes To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton Cc: David Hildenbrand , Matthew Wilcox , Vlastimil Babka , Lorenzo Stoakes Subject: [PATCH 0/2] Refactor do_fault_around() Date: Fri, 17 Mar 2023 21:58:24 +0000 Message-Id: X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Refactor do_fault_around() to avoid bitwise tricks and arather difficult to follow logic. Additionally, prefer fault_around_pages to fault_around_bytes as the operations are performed at a base page granularity. I have run this code against a small program I wrote which generates significant input data and compares output with the original function to ensure that it behaves the same as the old code across varying vmf, vma and fault_around_pages inputs. Lorenzo Stoakes (2): mm: refactor do_fault_around() mm: pefer fault_around_pages to fault_around_bytes mm/memory.c | 62 ++++++++++++++++++++++++++--------------------------- 1 file changed, 30 insertions(+), 32 deletions(-) -- 2.39.2