From mboxrd@z Thu Jan  1 00:00:00 1970
From: horserivers@gmail.com (horseriver)
Date: Fri, 11 Jan 2013 05:14:43 +0800
Subject: internel implemention of file operation
In-Reply-To: <CAAYFAvpB=tG-4L_M5c3myFAbaJoWjEWSfLEUYpankcD70NToEg@mail.gmail.com>
References: <20130103065931.GA20892@debian.localdomain>
	<CAAYFAvpB=tG-4L_M5c3myFAbaJoWjEWSfLEUYpankcD70NToEg@mail.gmail.com>
Message-ID: <20130110211443.GA4817@debian.localdomain>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

hi:

  these two wayes of operating one file :

  1.use open/write interface call .

  2.mmap this file into memory , then access this memory area and do r/w . 

  what is the essential difference between this teo wayes?

thanks!