From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <20000611010054.26508.qmail@web4402.mail.yahoo.com> Date: Sat, 10 Jun 2000 18:00:54 -0700 (PDT) From: Rakesh Mathur Subject: vm optimization MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.rutgers.edu, linux-mm@kvack.org List-ID: Linux MM system allocates/deallocates physical pages with a buddy system. So my question is what happens when fragmentations occurs. The fragmentation could get severe enough to not satisfy a request of size n even though overall those many pages are available. So, does the VM subsystem ever compact? For example say if each consecutive block of size 8 pages is occupied by 5 pages... then a request of size > 2 can not be satisfied until it compacts. I ask because now there are several cool algorithms available that can guarantee close to perfect memory utilization if a little bit of limited compaction is permitted! Has compaction ever been considered? Will it result in lot of overhad (several page tables will need to be changed, TLB entries will need to be updated etc)? Once again please cc me on replies... rakesh __________________________________________________ Do You Yahoo!? Yahoo! Photos -- now, 100 FREE prints! http://photos.yahoo.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux.eu.org/Linux-MM/