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From: Waiman Long <longman@redhat.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Davidlohr Bueso <dave@stgolabs.net>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>, Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH] hugetlbfs: Take read_lock on i_mmap for PMD sharing
Date: Thu, 7 Nov 2019 16:06:47 -0500	[thread overview]
Message-ID: <2d4b12a7-ea30-fe33-f59d-342346dfdec9@redhat.com> (raw)
In-Reply-To: <20191107194225.GE11823@bombadil.infradead.org>

On 11/7/19 2:42 PM, Matthew Wilcox wrote:
> On Thu, Nov 07, 2019 at 02:06:28PM -0500, Waiman Long wrote:
>> -	i_mmap_lock_write(mapping);
>> +	/*
>> +	 * PMD sharing does not require changes to i_mmap. So a read lock
>> +	 * is enuogh.
>> +	 */
>> +	i_mmap_lock_read(mapping);
> We don't have comments before any of the other calls to i_mmap_lock_read()
> justifying why we don't need the write lock.  I don't understand why this
> situation is different.  Just delete the comment and make this a two-line
> patch.
>
I am fine with that.

I will send a v2 patch.

Cheers,
Longman



  reply	other threads:[~2019-11-07 21:06 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-07 19:06 [PATCH] hugetlbfs: Take read_lock on i_mmap for PMD sharing Waiman Long
2019-11-07 19:13 ` Waiman Long
2019-11-07 19:15 ` Waiman Long
2019-11-07 19:31 ` Mike Kravetz
2019-11-07 19:42 ` Matthew Wilcox
2019-11-07 21:06   ` Waiman Long [this message]
2019-11-07 19:54 ` Matthew Wilcox
2019-11-07 21:27   ` Waiman Long
2019-11-07 21:49   ` Mike Kravetz
2019-11-07 21:56     ` Mike Kravetz
2019-11-08  2:04     ` Davidlohr Bueso
2019-11-08  3:22       ` Andrew Morton
2019-11-08 19:10       ` Mike Kravetz
2019-11-09  1:47         ` Mike Kravetz
2019-11-12 17:27           ` Waiman Long
2019-11-12 23:11             ` Mike Kravetz
2019-11-13  2:55               ` Waiman Long

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