From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ramkumar Ramachandra <artagnon@gmail.com>
Subject: Explanation for dropping write-back in mmap
Date: Mon, 7 Jun 2010 17:16:18 +0200
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Cc: Git Mailing List <git@vger.kernel.org>,
	David Michael Barr <david.barr@cordelta.com>,
	Sverre Rabbelier <srabbelier@gmail.com>,
	Jonathan Nieder <jrnieder@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
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Hi Junio,

In the commit f48000fcbe100, you've forced the caller to use
MAP_PRIVATE in the alternative mmap implementation dropping write-back
support. Could you kindly explain the rationale for this? David's SVN
exporter uses mmap with MAP_SHARED, and we figured that the merge
immediately breaks this functionality.

Noticed-by: Jonathan Nieder <jrnieder@gmail.com>

-----------------------------------------------------------------------------------------------------------
commit f48000fcbe1009c18f1cc46e56cde2cb632071fa
Author: Junio C Hamano <junkio@cox.net>
Date:   Sat Oct 8 15:54:36 2005 -0700

    Yank writing-back support from gitfakemmap.

    We do not write through our use of mmap(), so make sure callers pass
    MAP_PRIVATE and remove support for writing changes back.

    Signed-off-by: Junio C Hamano <junkio@cox.net>
-----------------------------------------------------------------------------------------------------------

Thanks.

-- Ram