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=ham 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 AC2E1C55186 for ; Wed, 22 Apr 2020 00:14:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 63D8020575 for ; Wed, 22 Apr 2020 00:14:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="fmE/ZsCi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63D8020575 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 146998E0006; Tue, 21 Apr 2020 20:14:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 11E488E0003; Tue, 21 Apr 2020 20:14:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 00D0A8E0006; Tue, 21 Apr 2020 20:14:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0164.hostedemail.com [216.40.44.164]) by kanga.kvack.org (Postfix) with ESMTP id DE8228E0003 for ; Tue, 21 Apr 2020 20:14:28 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 943B4349B for ; Wed, 22 Apr 2020 00:14:28 +0000 (UTC) X-FDA: 76733569416.17.train51_44253e60fd014 X-HE-Tag: train51_44253e60fd014 X-Filterd-Recvd-Size: 5682 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Wed, 22 Apr 2020 00:14:28 +0000 (UTC) Received: by mail-pf1-f201.google.com with SMTP id i128so564445pfc.4 for ; Tue, 21 Apr 2020 17:14:28 -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=j6a1bS4c8cPa3SIi/ZSBVgmA95A703jQkXjuPSo8A7P2Td8wtzQx3ffONeXetuSD4t fit7xSIc0NKysYfYSUhg3y4LMh6D5u8z275d2k/yB+FFkbr1CxOsh9GWF/91vZ9rwLXL lsfPDgNwctGiJ6LhCQhldW0+AMlGN/BkZqCTJsOusjvCE4+8TxmN1dmjCBo+vKpi9AiO xFYEnxGBlBBQLCqrmsaPt6Q11goS+FuHsNl3ETU2Qp5pIliibyab3XFmPX2dd9APTEW9 MRershNBZ8qeCrAZY+QvFijj+RMjOt8tWZShMm8zTs+tSdc0hOEuQ+Zi2hpk5xBGTPxr HIdg== X-Gm-Message-State: AGi0PubbFOvZdhFMEY2NB4qcyGylsJakQnjnWuemPql/q+VPH2eM4Oan DE2NrDGx3QeJNA3G/BGV1dxx854j2dQ= 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" 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: 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