From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f173.google.com (mail-pd0-f173.google.com [209.85.192.173]) by kanga.kvack.org (Postfix) with ESMTP id 396826B00CB for ; Thu, 6 Nov 2014 16:50:26 -0500 (EST) Received: by mail-pd0-f173.google.com with SMTP id v10so1939992pde.32 for ; Thu, 06 Nov 2014 13:50:26 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id h2si7125506pdk.90.2014.11.06.13.50.23 for ; Thu, 06 Nov 2014 13:50:24 -0800 (PST) Message-ID: <545BED0B.8000001@intel.com> Date: Thu, 06 Nov 2014 13:50:03 -0800 From: Dave Hansen MIME-Version: 1.0 Subject: Re: [PATCH v9 11/12] x86, mpx: cleanup unused bound tables References: <1413088915-13428-1-git-send-email-qiaowei.ren@intel.com> <1413088915-13428-12-git-send-email-qiaowei.ren@intel.com> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Thomas Gleixner , Qiaowei Ren Cc: "H. Peter Anvin" , Ingo Molnar , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@linux-mips.org Instead of all of these games with dropping and reacquiring mmap_sem and adding other locks, or deferring the work, why don't we just do a get_user_pages()? Something along the lines of: while (1) { ret = cmpxchg(addr) if (!ret) break; if (ret == -EFAULT) get_user_pages(addr); } Does anybody see a problem with that? -- 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