From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x244.google.com (mail-qk0-x244.google.com [IPv6:2607:f8b0:400d:c09::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vhxLY732vzDqGb for ; Tue, 14 Mar 2017 12:03:17 +1100 (AEDT) Received: by mail-qk0-x244.google.com with SMTP id o135so39410734qke.2 for ; Mon, 13 Mar 2017 18:03:17 -0700 (PDT) Sender: Richard Henderson Subject: Re: [RFC PATCH 00/13] Introduce first class virtual address spaces To: Till Smejkal , Ivan Kokshaysky , Matt Turner , Vineet Gupta , Russell King , Catalin Marinas , Will Deacon , Steven Miao , Richard Kuo , Tony Luck , Fenghua Yu , James Hogan , Ralf Baechle , "James E.J. Bottomley" , Helge Deller , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , Yoshinori Sato , Rich Felker , "David S. Miller" , Chris Metcalf , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Andy Lutomirski , Chris Zankel , Max Filippov , Arnd Bergmann , Greg Kroah-Hartman , Laurent Pinchart , Mauro Carvalho Chehab , Pawel Osciak , Marek Szyprowski , Kyungmin Park , David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , Felipe Balbi , Alexander Viro , Benjamin LaHaise , Nadia Yvette Chambers , Jeff Layton , "J. Bruce Fields" , Peter Zijlstra , Hugh Dickins , Arnaldo Carvalho de Melo , Alexander Shishkin , Jaroslav Kysela , Takashi Iwai , linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, adi-buildroot-devel@lists.sourceforge.net, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-media@vger.kernel.org, linux-mtd@lists.infradead.org, linux-usb@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-mm@kvack.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, alsa-devel@alsa-project.org References: <20170314003935.2jwycgajo7eojmvm@arch-dev> From: Richard Henderson Message-ID: Date: Tue, 14 Mar 2017 11:02:37 +1000 MIME-Version: 1.0 In-Reply-To: <20170314003935.2jwycgajo7eojmvm@arch-dev> Content-Type: text/plain; charset=windows-1252; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 03/14/2017 10:39 AM, Till Smejkal wrote: >> Is this an indication that full virtual address spaces are useless? It >> would seem like if you only use virtual address segments then you avoid all >> of the problems with executing code, active stacks, and brk. > > What do you mean with *virtual address segments*? The nice part of first class > virtual address spaces is that one can share/reuse collections of address space > segments easily. What do *I* mean? You introduced the term, didn't you? Rereading your original I see you called them "VAS segments". Anyway, whatever they are called, it would seem that these segments do not require any of the syncing mechanisms that are causing you problems. r~