From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-x22f.google.com (mail-wi0-x22f.google.com [IPv6:2a00:1450:400c:c05::22f]) (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 A3D6A1A1A7A for ; Wed, 22 Jul 2015 21:26:07 +1000 (AEST) Received: by wicgb10 with SMTP id gb10so93614194wic.1 for ; Wed, 22 Jul 2015 04:26:01 -0700 (PDT) Date: Wed, 22 Jul 2015 14:25:58 +0300 From: "Kirill A. Shutemov" To: Eric B Munson Cc: Andrew Morton , Michal Hocko , Vlastimil Babka , Paul Gortmaker , Chris Metcalf , Guenter Roeck , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH V4 5/6] mm: mmap: Add mmap flag to request VM_LOCKONFAULT Message-ID: <20150722112558.GC8630@node.dhcp.inet.fi> References: <1437508781-28655-1-git-send-email-emunson@akamai.com> <1437508781-28655-6-git-send-email-emunson@akamai.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1437508781-28655-6-git-send-email-emunson@akamai.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Jul 21, 2015 at 03:59:40PM -0400, Eric B Munson wrote: > The cost of faulting in all memory to be locked can be very high when > working with large mappings. If only portions of the mapping will be > used this can incur a high penalty for locking. > > Now that we have the new VMA flag for the locked but not present state, > expose it as an mmap option like MAP_LOCKED -> VM_LOCKED. What is advantage over mmap() + mlock(MLOCK_ONFAULT)? -- Kirill A. Shutemov