From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 16 Sep 2003 14:17:57 -0700 From: "Martin J. Bligh" Subject: Re: Freeing boot memory Message-ID: <3540000.1063747077@flay> In-Reply-To: <200309161817.37802.lmb@exatas.unisinos.br> References: <200309161817.37802.lmb@exatas.unisinos.br> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: Leandro Motta Barros , linux-mm@kvack.org Cc: sisopiii-l@cscience.org List-ID: > I and a colleague are studying the VM subsystem (actually this is the first > time we are examining the Linux source code more closely) and have a question > or two. > > Well, the questions concern the boot memory allocator. To be more precise, > We're interested in the memory deallocation routines. We have seen that it is > only possible to free full pages. So, theoretically, if we make several > allocations smaller than one page, we will not be able to actually free this > memory. I just don't know of this kind of situation happens in real life. Do > we currently have some pages of memory "wasted" because the boot memory > allocator was not able to free small allocations? Is there any estimate (or > benchmark or whatever) on the number of pages that could be freed but are > not? > > We have interest in hacking a little bit in the VM, and we thought that trying > to find out ways to avoid this problem (if this is really a problem) could be > nice. Do you have any thoughts about this? What would you *do* with this half a page? There's no main memory allocator to stick it in, as far as I can see. M. -- 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-mm.org/ . Don't email: aart@kvack.org