From mboxrd@z Thu Jan 1 00:00:00 1970 From: andi@firstfloor.org (Andi Kleen) Date: Wed, 29 Jun 2011 13:11:00 -0700 Subject: [PATCH 00/10] mm: Linux VM Infrastructure to support Memory Power Management In-Reply-To: <1309370342.11430.604.camel@nimitz> (Dave Hansen's message of "Wed, 29 Jun 2011 10:59:02 -0700") References: <1306499498-14263-1-git-send-email-ankita@in.ibm.com> <20110629130038.GA7909@in.ibm.com> <1309367184.11430.594.camel@nimitz> <20110629174220.GA9152@in.ibm.com> <1309370342.11430.604.camel@nimitz> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Dave Hansen writes: > > It's also going to be a pain to track kernel references. On x86, our Even if you tracked them what would you do with them? It's quite hard to stop using arbitary kernel memory (see all the dancing memory-failure does) You need to track the direct accesses to user data which happens to be accessed through the direct mapping. Also it will be always unreliable because this all won't track DMA. For that you would also need to track in the dma_* infrastructure, which will likely get seriously expensive. -Andi -- ak at linux.intel.com -- Speaking for myself only