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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 E499AC5518A for ; Wed, 22 Apr 2020 00:14:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B890120706 for ; Wed, 22 Apr 2020 00:14:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="fmE/ZsCi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726363AbgDVAO3 (ORCPT ); Tue, 21 Apr 2020 20:14:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726012AbgDVAO3 (ORCPT ); Tue, 21 Apr 2020 20:14:29 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE8F9C0610D5 for ; Tue, 21 Apr 2020 17:14:27 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id e18so530559pfl.17 for ; Tue, 21 Apr 2020 17:14:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=nj5jjGLg8IOvfnegjPnvO+hyr9F+Q3RFMzb65ktIqNg=; b=fmE/ZsCi12txej32MKxq5Q/M7SA+tr6q8bMHrxgAjcjNoXH82uOrxQ9hl0ksM/ez4f NPLpdNrNChzGenZ8mx71A3vcq8jSr23SjXXSs5JSrE1GiF3Gsd6gEiJ2zvEY29rNj2ac xIllsk8xqc1Z6k8VjXIaMEhazT8cisE6MUOlrpJfwmVX+L6xMjPj9HolikYBgotuYvcW r0Xde8JijOIxT99M4Wus0Ohme4Xh2bv5zz0NuyF5tAK8i+s1Pn1Dh7mc5uPWIz7CSOik LwX9Fi9+pGvkXqovzI6v/aNLkyYs+BMwHT6PMjF03zESDlDCfQEAZ1wd/Mm8hiPnuzBI q6HQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=nj5jjGLg8IOvfnegjPnvO+hyr9F+Q3RFMzb65ktIqNg=; b=qD/0UEZJqe1JdslfzKMOU6n9rbk1yKi1nSINdA6z6IHm83U0elwV76VOVE6KBFE98O WwA5CRigIEZRcghzyNeliFxxr2iDbtMnHogBQT+d+BFiuGncx2SQZSLJGWVKHtvRZWKF fzWxuAUxcdYBz9TY6vEbbwlfgspXf7xXPG3pCOGIJkexqIU+oFXlW5pf/g7KHCDEuVrM PJYTjSlmdFZ22/ggr3IdDY68C5lrLCOyfsmQu2k7gapC/yjNXQ6lF11Ff8gI293WX4wl KWBM6ZBi1nfNBFO+cSfrRRHrfOTEZ8XCyLxrQIvFlcZLYjz4j/ipDBVFFBsp2qmusDE0 TIhQ== X-Gm-Message-State: AGi0PuZFbbtzWQU5yq+fKY6MJYhBMWpRDY5VviXooc7E5nUBuWh5E9AE wJFTC2KO39w10gktf54+7/T2tQahmlw= X-Google-Smtp-Source: APiQypKlcSekBVajTIOBnih7IYmBCRTnYXbk0AAJ5N3mmuCItzToA2KSG7ErlRz3OGA48q1hRqMoFhPcOY0= X-Received: by 2002:a17:90a:276a:: with SMTP id o97mr8625466pje.194.1587514467186; Tue, 21 Apr 2020 17:14:27 -0700 (PDT) Date: Tue, 21 Apr 2020 17:14:13 -0700 In-Reply-To: <20200422001422.232330-1-walken@google.com> Message-Id: <20200422001422.232330-2-walken@google.com> Mime-Version: 1.0 References: <20200422001422.232330-1-walken@google.com> X-Mailer: git-send-email 2.26.1.301.g55bc3eb7cb9-goog Subject: [PATCH v5 01/10] mmap locking API: initial implementation as rwsem wrappers From: Michel Lespinasse To: Andrew Morton , linux-mm Cc: LKML , Peter Zijlstra , Laurent Dufour , Vlastimil Babka , Matthew Wilcox , Liam Howlett , Jerome Glisse , Davidlohr Bueso , David Rientjes , Hugh Dickins , Ying Han , Jason Gunthorpe , Daniel Jordan , Michel Lespinasse , Davidlohr Bueso Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This change wraps the existing mmap_sem related rwsem calls into a new mmap locking API. There are two justifications for the new API: - At first, it provides an easy hooking point to instrument mmap_sem locking latencies independently of any other rwsems. - In the future, it may be a starting point for replacing the rwsem implementation with a different one, such as range locks. Signed-off-by: Michel Lespinasse Reviewed-by: Daniel Jordan Reviewed-by: Davidlohr Bueso --- include/linux/mm.h | 1 + include/linux/mmap_lock.h | 54 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) create mode 100644 include/linux/mmap_lock.h diff --git a/include/linux/mm.h b/include/linux/mm.h index 5a323422d783..051ec782bdbb 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h new file mode 100644 index 000000000000..97ac53b66052 --- /dev/null +++ b/include/linux/mmap_lock.h @@ -0,0 +1,54 @@ +#ifndef _LINUX_MMAP_LOCK_H +#define _LINUX_MMAP_LOCK_H + +static inline void mmap_init_lock(struct mm_struct *mm) +{ + init_rwsem(&mm->mmap_sem); +} + +static inline void mmap_write_lock(struct mm_struct *mm) +{ + down_write(&mm->mmap_sem); +} + +static inline int mmap_write_lock_killable(struct mm_struct *mm) +{ + return down_write_killable(&mm->mmap_sem); +} + +static inline bool mmap_write_trylock(struct mm_struct *mm) +{ + return down_write_trylock(&mm->mmap_sem) != 0; +} + +static inline void mmap_write_unlock(struct mm_struct *mm) +{ + up_write(&mm->mmap_sem); +} + +static inline void mmap_write_downgrade(struct mm_struct *mm) +{ + downgrade_write(&mm->mmap_sem); +} + +static inline void mmap_read_lock(struct mm_struct *mm) +{ + down_read(&mm->mmap_sem); +} + +static inline int mmap_read_lock_killable(struct mm_struct *mm) +{ + return down_read_killable(&mm->mmap_sem); +} + +static inline bool mmap_read_trylock(struct mm_struct *mm) +{ + return down_read_trylock(&mm->mmap_sem) != 0; +} + +static inline void mmap_read_unlock(struct mm_struct *mm) +{ + up_read(&mm->mmap_sem); +} + +#endif /* _LINUX_MMAP_LOCK_H */ -- 2.26.1.301.g55bc3eb7cb9-goog