From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 11 Mar 2008 21:35:25 -0700 From: Andrew Morton Subject: Re: [patch 0/7] [rfc] VM_MIXEDMAP, pte_special, xip work Message-Id: <20080311213525.a5994894.akpm@linux-foundation.org> In-Reply-To: <20080311104653.995564000@nick.local0.net> References: <20080311104653.995564000@nick.local0.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: npiggin@nick.local0.net Cc: Linus Torvalds , Jared Hulbert , Carsten Otte , Martin Schwidefsky , Heiko Carstens , linux-mm@kvack.org List-ID: On Tue, 11 Mar 2008 21:46:53 +1100 npiggin@nick.local0.net wrote: > -- > > (doh, please ignore the previous "x/6" patches, they're old. The > new ones are these x/7 set) > > Hi, > > I'm sorry for neglecting these patches for a few weeks :( > > I'd like to still get them into -mm and aim for the next merge window -- > they've been gradually getting a pretty reasonable amount of review and > testing. I think the implementation of the pte_special path in vm_normal_page > and vm_insert_mixed was the only point left unresolved since last time. > > I've included the dual kaddr/pfn API that we worked out with Jared, but > he hasn't yet tested my patch rollup... so this is an RFC only. If we all > agree on it, then I'll rebase to -mm and submit. > umm, could we have some executive summary about what this is all supposed to achieve? I can see what each patch does, but what's the overall result? [1/7] says: > VM_MIXEDMAP achieves this by refcounting all pfn_valid pages, and not > refcounting !pfn_valid pages (which is not an option for VM_PFNMAP, because > it needs to avoid refcounting pfn_valid pages eg. for /dev/mem mappings). I have this vague feeling that pfn_valid() isn't reliable - it can sometimes lie, and that making it truthful was considered too expensive. But maybe I'm thinking of something else? -- 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: email@kvack.org