From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60083) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VTtAo-0003iP-OV for qemu-devel@nongnu.org; Wed, 09 Oct 2013 08:47:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VTtAk-00022V-DR for qemu-devel@nongnu.org; Wed, 09 Oct 2013 08:47:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42066) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VTtAk-000226-66 for qemu-devel@nongnu.org; Wed, 09 Oct 2013 08:47:26 -0400 Date: Tue, 8 Oct 2013 15:23:24 +0300 From: Gleb Natapov Message-ID: <20131008122324.GC3574@redhat.com> References: <20131006024741.61cc8512@desk.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131006024741.61cc8512@desk.lan> Subject: Re: [Qemu-devel] problems with 1G hugepages and linux 3.12-rc3 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: andy123 Cc: Andrea Arcangeli , qemu-devel@nongnu.org, kvm@vger.kernel.org Copying Andrea, On Sun, Oct 06, 2013 at 02:47:41AM +0200, andy123 wrote: > Hi, > > as the subject states, I have some problems with 1G hugepages with qemu(-vfio-git) on Linux 3.12-rc3. > > I start qemu like this, for example: > "/usr/bin/qemu-system-x86_64 -enable-kvm -m 1024 -mem-path /dev/hugepages -drive file=/files/vm/arch.img,if=virtio,media=disk -monitor stdio" > where /dev/hugepages is "hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,mode=1770,gid=78,pagesize=1G,pagesize=1G)" > and the kernel is booted with "hugepagesz=1G hugepages=4". > This result in lots of error message in dmesg, as seen here: https://gist.github.com/ajs124/6842823 (starting at 18:04:28) > > After starting and stopping multiple virtual machines, the hugepages seem to "fill up" and qemu outputs > "file_ram_alloc: can't mmap RAM pages: Cannot allocate memory", but works anyways. > With fill up, I mean that I can start qemu 2 time with "-m 2048" and 4 times with "-m 1024", before it fails to mmap. > I can reproduce huge page leak, but not oops, but they can be related. Can you revert 11feeb498086a3a5907b8148bdf1786a9b18fc55 and retry? > This works without any problems in 3.11.x and also with 2M hugepages (umount /dev/hugepages && mount -t hugetlbfs -o pagesize=2048k /dev/hugepages). > > I'm running this in arch linux and there has already been some discussion on the arch forums (https://bbs.archlinux.org/viewtopic.php?pid=1333469#p1333469) but I tried to add everything I wrote over there in this mail. > > In case I missed something or you need more information, I'll happily supply it in order to get this resolved. > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Gleb.