X-Recipient: archive-cygwin@delorie.com X-Spam-Check-By: sourceware.org Date: Fri, 16 Jan 2009 17:41:09 +0100 From: Corinna Vinschen To: cygwin@cygwin.com Subject: Re: how to get mmap page size? Message-ID: <20090116164108.GT400@calimero.vinschen.de> Reply-To: cygwin@cygwin.com Mail-Followup-To: cygwin@cygwin.com References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com On Jan 16 15:10, Jay Foad wrote: > Corinna Vinschen wrote: > > > mmap always allocates in 64K chunks. > > That doesn't seem to be true in practice. In the test below I mmap a > 1080K file (this is a multiple of 4K but not a multiple of 64K). The > first byte after the end of the file isn't readable. Right. The reason is that mmap started to map memory top down at one point to fix a problem with Windows Vista. The mechanism to align the map always to 64K is still in Cygwin, but it currently doesn't work for files. I'll have a look into fixing that for Cygwin 1.7. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Project Co-Leader cygwin AT cygwin DOT com Red Hat -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/