From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laura Abbott Subject: Re: [RFC PATCH 3/3] mm/map_contig: Add mmap(MAP_CONTIG) support Date: Mon, 16 Oct 2017 14:03:16 -0700 Message-ID: <4994fc18-f0ee-300d-d61f-c1a1b63e55e4@redhat.com> References: <20171013084054.me3kxhgbxzgm2lpr@dhcp22.suse.cz> <20171013152801.nbpk6nluotgbmfrs@dhcp22.suse.cz> <20171013154747.2jv7rtfqyyagiodn@dhcp22.suse.cz> <20171013161736.htumyr4cskfrjq64@dhcp22.suse.cz> <752b49eb-55c6-5a34-ab41-6e91dd93ea70@mellanox.com> <20171016180749.2y2v4ucchb33xnde@dhcp22.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: owner-linux-mm@kvack.org To: Mike Kravetz , Michal Hocko Cc: Guy Shattah , Christopher Lameter , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Marek Szyprowski , Michal Nazarewicz , "Aneesh Kumar K . V" , Joonsoo Kim , Anshuman Khandual , Vlastimil Babka List-Id: linux-api@vger.kernel.org On 10/16/2017 01:32 PM, Mike Kravetz wrote: > On 10/16/2017 11:07 AM, Michal Hocko wrote: >> On Mon 16-10-17 10:43:38, Mike Kravetz wrote: >>> Just to be clear, the posix standard talks about a typed memory object. >>> The suggested implementation has one create a connection to the memory >>> object to receive a fd, then use mmap as usual to get a mapping backed >>> by contiguous pages/memory. Of course, this type of implementation is >>> not a requirement. >> >> I am not sure that POSIC standard for typed memory is easily >> implementable in Linux. Does any OS actually implement this API? > > A quick search only reveals Blackberry QNX and PlayBook OS. > > Also somewhat related. In a earlier thread someone pointed out this > out of tree module used for contiguous allocations in SOC (and other?) > environments. It even has the option of making use of CMA. > http://processors.wiki.ti.com/index.php/CMEM_Overview > If we're at the point where we're discussing CMEM, I'd like to point out that ion (drivers/staging/android/ion) already provides an ioctl interface to allocate CMA and other types of memory. It's mostly used for Android as the name implies. I don't pretend the interface is perfect but it could be useful as a discussion point for allocation interfaces. Thanks, Laura -- 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