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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D1FADFA3728 for ; Wed, 16 Oct 2019 17:02:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5AA221D7A for ; Wed, 16 Oct 2019 17:02:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436493AbfJPRC1 (ORCPT ); Wed, 16 Oct 2019 13:02:27 -0400 Received: from mga05.intel.com ([192.55.52.43]:14328 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729913AbfJPRC0 (ORCPT ); Wed, 16 Oct 2019 13:02:26 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Oct 2019 10:02:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,304,1566889200"; d="scan'208";a="199012720" Received: from schen9-desk.jf.intel.com (HELO [10.54.74.162]) ([10.54.74.162]) by orsmga003.jf.intel.com with ESMTP; 16 Oct 2019 10:02:25 -0700 To: Linus Torvalds , David Howells , Kan Liang Cc: Casey Schaufler , Stephen Smalley , Greg Kroah-Hartman , Nicolas Dichtel , raven@themaw.net, Christian Brauner , keyrings@vger.kernel.org, linux-usb@vger.kernel.org, linux-block , LSM List , linux-fsdevel , Linux API , Linux Kernel Mailing List References: <157117606853.15019.15459271147790470307.stgit@warthog.procyon.org.uk> <157117608708.15019.1998141309054662114.stgit@warthog.procyon.org.uk> From: Tim Chen Openpgp: preference=signencrypt Autocrypt: addr=tim.c.chen@linux.intel.com; prefer-encrypt=mutual; keydata= mQINBE6ONugBEAC1c8laQ2QrezbYFetwrzD0v8rOqanj5X1jkySQr3hm/rqVcDJudcfdSMv0 BNCCjt2dofFxVfRL0G8eQR4qoSgzDGDzoFva3NjTJ/34TlK9MMouLY7X5x3sXdZtrV4zhKGv 3Rt2osfARdH3QDoTUHujhQxlcPk7cwjTXe4o3aHIFbcIBUmxhqPaz3AMfdCqbhd7uWe9MAZX 7M9vk6PboyO4PgZRAs5lWRoD4ZfROtSViX49KEkO7BDClacVsODITpiaWtZVDxkYUX/D9OxG AkxmqrCxZxxZHDQos1SnS08aKD0QITm/LWQtwx1y0P4GGMXRlIAQE4rK69BDvzSaLB45ppOw AO7kw8aR3eu/sW8p016dx34bUFFTwbILJFvazpvRImdjmZGcTcvRd8QgmhNV5INyGwtfA8sn L4V13aZNZA9eWd+iuB8qZfoFiyAeHNWzLX/Moi8hB7LxFuEGnvbxYByRS83jsxjH2Bd49bTi XOsAY/YyGj6gl8KkjSbKOkj0IRy28nLisFdGBvgeQrvaLaA06VexptmrLjp1Qtyesw6zIJeP oHUImJltjPjFvyfkuIPfVIB87kukpB78bhSRA5mC365LsLRl+nrX7SauEo8b7MX0qbW9pg0f wsiyCCK0ioTTm4IWL2wiDB7PeiJSsViBORNKoxA093B42BWFJQARAQABtDRUaW0gQ2hlbiAo d29yayByZWxhdGVkKSA8dGltLmMuY2hlbkBsaW51eC5pbnRlbC5jb20+iQI+BBMBAgAoAhsD BgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAUCXFIuxAUJEYZe0wAKCRCiZ7WKota4STH3EACW 1jBRzdzEd5QeTQWrTtB0Dxs5cC8/P7gEYlYQCr3Dod8fG7UcPbY7wlZXc3vr7+A47/bSTVc0 DhUAUwJT+VBMIpKdYUbvfjmgicL9mOYW73/PHTO38BsMyoeOtuZlyoUl3yoxWmIqD4S1xV04 q5qKyTakghFa+1ZlGTAIqjIzixY0E6309spVTHoImJTkXNdDQSF0AxjW0YNejt52rkGXXSoi IgYLRb3mLJE/k1KziYtXbkgQRYssty3n731prN5XrupcS4AiZIQl6+uG7nN2DGn9ozy2dgTi smPAOFH7PKJwj8UU8HUYtX24mQA6LKRNmOgB290PvrIy89FsBot/xKT2kpSlk20Ftmke7KCa 65br/ExDzfaBKLynztcF8o72DXuJ4nS2IxfT/Zmkekvvx/s9R4kyPyebJ5IA/CH2Ez6kXIP+ q0QVS25WF21vOtK52buUgt4SeRbqSpTZc8bpBBpWQcmeJqleo19WzITojpt0JvdVNC/1H7mF 4l7og76MYSTCqIKcLzvKFeJSie50PM3IOPp4U2czSrmZURlTO0o1TRAa7Z5v/j8KxtSJKTgD lYKhR0MTIaNw3z5LPWCCYCmYfcwCsIa2vd3aZr3/Ao31ZnBuF4K2LCkZR7RQgLu+y5Tr8P7c e82t/AhTZrzQowzP0Vl6NQo8N6C2fcwjSrkCDQROjjboARAAx+LxKhznLH0RFvuBEGTcntrC 3S0tpYmVsuWbdWr2ZL9VqZmXh6UWb0K7w7OpPNW1FiaWtVLnG1nuMmBJhE5jpYsi+yU8sbMA 5BEiQn2hUo0k5eww5/oiyNI9H7vql9h628JhYd9T1CcDMghTNOKfCPNGzQ8Js33cFnszqL4I N9jh+qdg5FnMHs/+oBNtlvNjD1dQdM6gm8WLhFttXNPn7nRUPuLQxTqbuoPgoTmxUxR3/M5A KDjntKEdYZziBYfQJkvfLJdnRZnuHvXhO2EU1/7bAhdz7nULZktw9j1Sp9zRYfKRnQdIvXXa jHkOn3N41n0zjoKV1J1KpAH3UcVfOmnTj+u6iVMW5dkxLo07CddJDaayXtCBSmmd90OG0Odx cq9VaIu/DOQJ8OZU3JORiuuq40jlFsF1fy7nZSvQFsJlSmHkb+cDMZDc1yk0ko65girmNjMF hsAdVYfVsqS1TJrnengBgbPgesYO5eY0Tm3+0pa07EkONsxnzyWJDn4fh/eA6IEUo2JrOrex O6cRBNv9dwrUfJbMgzFeKdoyq/Zwe9QmdStkFpoh9036iWsj6Nt58NhXP8WDHOfBg9o86z9O VMZMC2Q0r6pGm7L0yHmPiixrxWdW0dGKvTHu/DH/ORUrjBYYeMsCc4jWoUt4Xq49LX98KDGN dhkZDGwKnAUAEQEAAYkCJQQYAQIADwIbDAUCXFIulQUJEYZenwAKCRCiZ7WKota4SYqUEACj P/GMnWbaG6s4TPM5Dg6lkiSjFLWWJi74m34I19vaX2CAJDxPXoTU6ya8KwNgXU4yhVq7TMId keQGTIw/fnCv3RLNRcTAapLarxwDPRzzq2snkZKIeNh+WcwilFjTpTRASRMRy9ehKYMq6Zh7 PXXULzxblhF60dsvi7CuRsyiYprJg0h2iZVJbCIjhumCrsLnZ531SbZpnWz6OJM9Y16+HILp iZ77miSE87+xNa5Ye1W1ASRNnTd9ftWoTgLezi0/MeZVQ4Qz2Shk0MIOu56UxBb0asIaOgRj B5RGfDpbHfjy3Ja5WBDWgUQGgLd2b5B6MVruiFjpYK5WwDGPsj0nAOoENByJ+Oa6vvP2Olkl gQzSV2zm9vjgWeWx9H+X0eq40U+ounxTLJYNoJLK3jSkguwdXOfL2/Bvj2IyU35EOC5sgO6h VRt3kA/JPvZK+6MDxXmm6R8OyohR8uM/9NCb9aDw/DnLEWcFPHfzzFFn0idp7zD5SNgAXHzV PFY6UGIm86OuPZuSG31R0AU5zvcmWCeIvhxl5ZNfmZtv5h8TgmfGAgF4PSD0x/Bq4qobcfaL ugWG5FwiybPzu2H9ZLGoaRwRmCnzblJG0pRzNaC/F+0hNf63F1iSXzIlncHZ3By15bnt5QDk l50q2K/r651xphs7CGEdKi1nU0YJVbQxJQ== Subject: Re: [RFC PATCH 02/21] Add a prelocked wake-up Message-ID: <533ca3c5-1592-e59b-eafe-bc4a352a442d@linux.intel.com> Date: Wed, 16 Oct 2019 10:02:24 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On 10/15/19 3:14 PM, Linus Torvalds wrote: > On Tue, Oct 15, 2019 at 2:48 PM David Howells wrote: >> >> Add a wakeup call for a case whereby the caller already has the waitqueue >> spinlock held. > > That naming is crazy. > > We already have helper functions like this, and they are just called > "wake_up_locked()". > > So the "prelocked" naming is just odd. Make it be > wake_up_interruptible_sync_poll_locked(). > > The helper function should likely be > > void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, > unsigned int mode, void *key) > { > __wake_up_common(wq_head, mode, 1, WF_SYNC, key, NULL); > } > EXPORT_SYMBOL_GPL(__wake_up_locked_sync_key); > > to match the other naming patterns there. > > [ Unrelated ] > > Looking at that mess of functions, I also wonder if we should try to > just remove the bookmark code again. It was cute, and it was useful, > but I think the problem with the page lock list may have been fixed by > commit 9a1ea439b16b ("mm: put_and_wait_on_page_locked() while page is > migrated") which avoids the retry condition with > migrate_page_move_mapping(). > > Tim/Kan? Do you have the problematic load still? > Unfortunately, we do not have ready access to that problematic load which was run by a customer on 8 socket system. They were not willing to give the workload to us, and have not responded to my request to rerun their load with commit 9a1ea439b16b. The commit greatly reduced migration failures with concurrent page faulting. And successful migrations could have prevented the big pile up of waiters faulting and waiting on the page, which was the problem the bookmark code was trying to solve. So I also tend to think that the problem should have been resolved. But unfortunately I don't have a ready workload to confirm. Tim