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Subject: Re: [PATCH v5 01/10] mmap locking API: initial implementation as
 rwsem wrappers
To:     Michel Lespinasse <walken@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-mm <linux-mm@kvack.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Laurent Dufour <ldufour@linux.ibm.com>,
        Matthew Wilcox <willy@infradead.org>,
        Liam Howlett <Liam.Howlett@oracle.com>,
        Jerome Glisse <jglisse@redhat.com>,
        Davidlohr Bueso <dave@stgolabs.net>,
        David Rientjes <rientjes@google.com>,
        Hugh Dickins <hughd@google.com>, Ying Han <yinghan@google.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Daniel Jordan <daniel.m.jordan@oracle.com>,
        Davidlohr Bueso <dbueso@suse.de>
References: <20200422001422.232330-1-walken@google.com>
 <20200422001422.232330-2-walken@google.com>
From:   Vlastimil Babka <vbabka@suse.cz>
Message-ID: <a6ff3c5c-a6f6-c86d-aab6-f9f9b04c88ac@suse.cz>
Date:   Mon, 18 May 2020 11:28:08 +0200
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On 4/22/20 2:14 AM, 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 <walken@google.com>
> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
> Reviewed-by: Davidlohr Bueso <dbueso@suse.de>

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>