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,URIBL_BLOCKED, 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 227D2C433DF for ; Wed, 20 May 2020 05:29:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 005FE20899 for ; Wed, 20 May 2020 05:29:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="viUE7Q+6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726799AbgETF3P (ORCPT ); Wed, 20 May 2020 01:29:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726309AbgETF3O (ORCPT ); Wed, 20 May 2020 01:29:14 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41465C061A0E for ; Tue, 19 May 2020 22:29:14 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id z5so2479075qtz.16 for ; Tue, 19 May 2020 22:29:14 -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=oOKvTis22eNP85Mz9uA/OFT+qhsmJnOFthnsf9VGQzY=; b=viUE7Q+662+IkzFyahnIaYCnJOcXUlVMMDblrHEottDjc4iw8rS5qp3VqL4d9yk4Vl iLsXOlQhtl3Ni8WVCgiTZAXlThHQbBvCRAruZTCadGC5QNJOhYhwVNk58yb7zQWAZpQN m8ea7beMEQVkgnGQE8Kw6TLPJN7uFnreHrikVsiGxB1medgieO5mUY71oBVYYFXFEw1R Qa/W2numx5WhO4pGHeSPhIJZA38/obPSutq/xKAvxx2hwi7DQ8F7U8hqjk85lLb++Wae 8kn2/mNtLie+rrR4TFWKimt/EH4874ceN9jQNTeozxR3hAL//stq/IC+ACWdKSdQQzRI wB+Q== 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=oOKvTis22eNP85Mz9uA/OFT+qhsmJnOFthnsf9VGQzY=; b=FLOd3Whx9PMRNEsNcpY4sO58UHrRFNRVKKcu/3/j5ocH+FMGMAS3+Uou9QalNRkO1M KzdeVxA5wV0nBrcwyM8feUIRK9d7sXDCU51aQgwJtWH1mDAmbggXTfwlyW77kGLPJjWi bqIUMjoFlXNKGc1QazJmhlb1FmoekHnIU6EkAk2M1OExYqLYoJzEuoajKbLsN9zyz68u 6aDVeCXUXWmUFlbQ2tn3efZPNYI4pPrtGQBjRT7vjxOozakn06NfEoy1EEE6vkMNhxS0 X0S6UmtzqWbFf2kKg3Qcq4bWum+ioNMZWugp/JYCZCdOTeBFABv9iytunMYQofQp44Eb wlXQ== X-Gm-Message-State: AOAM530VFsewAeTmTG/Zw1dAypBxErf9Hn05KMN/MvDKi8cB762Wsdej sI7HyY0gSWbYPPOnJaqDv3FUXYqsUMI= X-Google-Smtp-Source: ABdhPJxHdmAtEVnKOxk3BiJr7dFV6qDRiCtdOzttrQ1X4xOxgL+hGpFSTwe8fs+Y0mMKYecBu0kd59Z48Fg= X-Received: by 2002:a05:6214:1248:: with SMTP id q8mr3157078qvv.130.1589952553394; Tue, 19 May 2020 22:29:13 -0700 (PDT) Date: Tue, 19 May 2020 22:28:57 -0700 In-Reply-To: <20200520052908.204642-1-walken@google.com> Message-Id: <20200520052908.204642-2-walken@google.com> Mime-Version: 1.0 References: <20200520052908.204642-1-walken@google.com> X-Mailer: git-send-email 2.26.2.761.g0e0b3e54be-goog Subject: [PATCH v6 01/12] 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 , John Hubbard , 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 Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka --- 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 */ -- 2.26.2.761.g0e0b3e54be-goog