From: David Turner <dturner@twopensource.com>
Date: Thu, 10 Mar 2016 00:09:08 GMT
Subject: Re: [PATCH 03/19] read-cache: allow to keep mmap'd memory after reading
Message-ID: <1457568548.13557.13.camel@twopensource.com>
In-Reply-To: <xmqqziu7fe6u.fsf@gitster.mtv.corp.google.com>

On Wed, 2016-03-09 at 15:02 -0800, Junio C Hamano wrote:
> David Turner <dturner@twopensource.com> writes:
> 
> > From: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> > 
> > Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> > ---
> 
> As usual in Duy's patches, this one seriously lacks "why".  And also
> makes the reader wonder if the memory region is ever unmapped() and
> if so under what condition.

How about this:

Later, we will introduce git index-helper to share this memory with
other git processes.

Since the memory will be shared, it will never be unmapped (although
the kernel may of course choose to page it out).