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Date:   Mon, 20 Apr 2020 12:28:06 -0700
From:   Matthew Wilcox <willy@infradead.org>
To:     Michel Lespinasse <walken@google.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-mm <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Laurent Dufour <ldufour@linux.ibm.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        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>
Subject: Re: [PATCH v4 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER
Message-ID: <20200420192806.GE5820@bombadil.infradead.org>
References: <20200415004353.130248-1-walken@google.com>
 <20200415004353.130248-9-walken@google.com>
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On Tue, Apr 14, 2020 at 05:43:51PM -0700, Michel Lespinasse wrote:
> @@ -90,7 +90,7 @@ static struct mm_struct tboot_mm = {
                                            ^^^^^^^^
>  	.pgd            = swapper_pg_dir,
>  	.mm_users       = ATOMIC_INIT(2),
>  	.mm_count       = ATOMIC_INIT(1),
> -	.mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
> +	.mmap_sem       = MMAP_LOCK_INITIALIZER(init_mm.mmap_sem),
                                                ^^^^^^^

Shome mishtake, shirley?

I don't see that this particular patch buys us much.  The name 'mmap_sem'
is still used, and I appreciate we abstract away the type of the lock,
but wouldn't this be better?

-	.mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
+	MMAP_LOCK_INITIALIZER(tboot_mm),