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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 1A4E0C2D0E8 for ; Sat, 28 Mar 2020 08:58:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7174206F2 for ; Sat, 28 Mar 2020 08:58:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bmG8Fngn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726268AbgC1I6G (ORCPT ); Sat, 28 Mar 2020 04:58:06 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:38575 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725937AbgC1I6G (ORCPT ); Sat, 28 Mar 2020 04:58:06 -0400 Received: by mail-wr1-f68.google.com with SMTP id s1so14563724wrv.5 for ; Sat, 28 Mar 2020 01:58:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to; bh=Hk5QBHZRLForL8IxdtPFDonNjjnSHHBgQoFEVQhsiQE=; b=bmG8FngnsfMDZyGz2Y6aVfpwS39pal1GzSzJT10vD/VQP8zANP3T8IvGfYv4Zjgi05 /uzFC5g9p37PW1zl570eNkWfWRZZAFMA3Krt24bMpWObQ9PsMEFS+4nh0/vP8yhwPvlz 2+3ggo6hW6g6JF2mB557BQRXc6RXD4lQ6w8WfZcIz0ynws/O2xREammWSbnIPzXlrjOS IiGXQ/2R2ir7JuMpoIn7FLct33kVvpCT9rC9RqFjYtfizOvPV494/gYxDMhRVhdCaVSQ JlQhXTqy2bDnlc2scjOFjUQ15JUqfhDS6JDYAZ005IrvdyOmSknQpYcB9VI1Fy+1Iktw KfZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to; bh=Hk5QBHZRLForL8IxdtPFDonNjjnSHHBgQoFEVQhsiQE=; b=eXUE3E/OMi9RGMtvEKcevf++i8OT9tidoN4a8xitf19cqV0sOa7QbLwjKdo/nWG80j R9hYKR0H69JkUyq70gC24pDw72ejsNTEwG8d9VattMq+KByVa7r6JNl/vziU7+SIFWNU crfJsY7tuHsP8bjOQQOI9wYWmdoFgg4Og5dgRPc3FeZMTaQcvaV7v6fdeu8XTm1RL3Ie WuUIGMeVJ6654EJKP8KjUrS0/Z2H+AAcF/TOpoHE6kGNMoiKXxv/oj11h3eKW+dAw3NZ aB8nGz9nlgPALDeMQKB7ZGf1n6GhqTjB3w3O2Ymkck088ZquPt5JAidYvnpitHgWcJqt jSBQ== X-Gm-Message-State: ANhLgQ1pB8gmCALzDs0JNewud5MI1RfS4cHHoYmViFtochft7Alpsc7C r+vj2a1eZ8DOc8kOauk7p6M= X-Google-Smtp-Source: ADFU+vvjdn14hIYWcgsmK8E3RUBnSIQAXrVnIl8g3DoIgmCHozbkYVS3i+s4E4s0vbmRyZ/R2e0Ofg== X-Received: by 2002:adf:b1c1:: with SMTP id r1mr3610121wra.337.1585385884481; Sat, 28 Mar 2020 01:58:04 -0700 (PDT) Received: from localhost.localdomain ([2a02:2450:10d2:194d:903b:8e3c:b688:90ef]) by smtp.gmail.com with ESMTPSA id 189sm7766207wme.31.2020.03.28.01.58.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 28 Mar 2020 01:58:03 -0700 (PDT) From: SeongJae Park To: Michel Lespinasse Cc: Andrew Morton , linux-mm , 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 Subject: Re: [PATCH v3 01/10] mmap locking API: initial implementation as rwsem wrappers (Michel Lespinasse) Date: Sat, 28 Mar 2020 09:57:46 +0100 Message-Id: <20200328085746.4773-1-sj38.park@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200327225102.25061-2-walken@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-03-27T15:50:53-07:00 Michel Lespinasse wrote: > 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 | 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 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..8b5a3cd56118 > --- /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_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); > +} > + > +#endif /* _LINUX_MMAP_LOCK_H */ Reviewed-by: SeongJae Park > -- > 2.26.0.rc2.310.g2932bb562d-goog >