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 ABF65C2D0EC for ; Fri, 27 Mar 2020 02:11:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E73520787 for ; Fri, 27 Mar 2020 02:11:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ctQS9IVG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727733AbgC0CLG (ORCPT ); Thu, 26 Mar 2020 22:11:06 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:36543 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726496AbgC0CLG (ORCPT ); Thu, 26 Mar 2020 22:11:06 -0400 Received: by mail-pg1-f202.google.com with SMTP id b130so6665174pga.3 for ; Thu, 26 Mar 2020 19:11:04 -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=k3mg/Xv1vow8pC5LkbfxQBusgzgffIOWBI4VPXD50U0=; b=ctQS9IVGYiGEW7rl+HmsBcEN7a8KNQhybe0fatUUL80bnaVg07X0r4Z76JZLH6V0Mo XpfvBX77aacV8cFXAYg4+Enm8dakUMTe6Jv/0It0M5CK6Md1vNkyHlw0PYEOEhWdxQfz L8HIXNoIstB3xK67EM/3psplE6E57IGlmG8eGLyJ4HmPHXi978x5J1W/b+DOuhyajt3I FVyCRvmzmXKduPC4z/1rKsUD1MRGkDiPDkXBsjsNCOsGSQtBpZ+Piv47z+PRwUzDv4Go +wAIo9kqMzgIoh50ZgkmbqZSye8yDI8U/MrFVTzz+Ovs4miWa7OAzcBRRT1yYqsAdPXn ue+g== 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=k3mg/Xv1vow8pC5LkbfxQBusgzgffIOWBI4VPXD50U0=; b=qLJHLwKVZWNMG+iIrMKTzgGplj9Ks3eaWfMdC9n/33ZXJb1+XjkypO2u1q9You7yVg IELLHQ4M39pywpaSXnmti+v/kT9uZUHEFKpxSQbTAjkL45USIlX0DLMevF9apdNVC0d7 pYsaSByzExKf/FErvN5x4dUKw4HrPoCx7jSvyH+uruMxPClCY9ayCnh/GaDRV7TxxPcf e1wtKCcRL3ahLpSOJvxv/R/6ou7/tSiNzIMOaiE5JMIFpWl20z6mI3+x+gEwnebVBfcx 99XjyDDpq+b4iybdei3jFkg55XlczVUCHHszzOC4QAoiGX3ej9xOQYrBzRznKG7veoHH oCBQ== X-Gm-Message-State: ANhLgQ1izt91XM2GhTqV5wJo0p4trHZkib5JdaJnJ/K9/2JUgo16MHpB DED6s3q3W7R9TxR5E8+DmJtbEBqb2tI= X-Google-Smtp-Source: ADFU+vsFGah9Sh4ZVgJlSbmDCL6eph1s6ibCkBkTza6XI3kWyCX6f4qL10bauS5CGXkC8UgYhDMAiiQFlwI= X-Received: by 2002:a65:4d09:: with SMTP id i9mr10912905pgt.403.1585275063502; Thu, 26 Mar 2020 19:11:03 -0700 (PDT) Date: Thu, 26 Mar 2020 19:10:49 -0700 In-Reply-To: <20200327021058.221911-1-walken@google.com> Message-Id: <20200327021058.221911-2-walken@google.com> Mime-Version: 1.0 References: <20200327021058.221911-1-walken@google.com> X-Mailer: git-send-email 2.26.0.rc2.310.g2932bb562d-goog Subject: [PATCH v2 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 , Markus Elfring , Michel Lespinasse 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 --- include/linux/mm.h | 1 + include/linux/mmap_lock.h | 59 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+) create mode 100644 include/linux/mmap_lock.h diff --git a/include/linux/mm.h b/include/linux/mm.h index c54fb96cb1e6..2f13c9198999 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..cffd25afe92b --- /dev/null +++ b/include/linux/mmap_lock.h @@ -0,0 +1,59 @@ +#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_downgrade_write_lock(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); +} + +static inline bool mmap_is_locked(struct mm_struct *mm) +{ + return rwsem_is_locked(&mm->mmap_sem) != 0; +} + +#endif /* _LINUX_MMAP_LOCK_H */ -- 2.26.0.rc2.310.g2932bb562d-goog