From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40726) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZsYci-0005wT-JH for qemu-devel@nongnu.org; Sat, 31 Oct 2015 12:03:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZsYcf-0006p4-Dt for qemu-devel@nongnu.org; Sat, 31 Oct 2015 12:03:20 -0400 Received: from mga14.intel.com ([192.55.52.115]:10369) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZsYcf-0006oW-8T for qemu-devel@nongnu.org; Sat, 31 Oct 2015 12:03:17 -0400 References: <1446184587-142784-1-git-send-email-guangrong.xiao@linux.intel.com> <1446184587-142784-9-git-send-email-guangrong.xiao@linux.intel.com> <563378E1.5000101@virtuozzo.com> <56347167.3060206@linux.intel.com> <20151031135531.GD7865@thinpad.lan.raisama.net> From: Xiao Guangrong Message-ID: <5634E4B3.10401@linux.intel.com> Date: Sat, 31 Oct 2015 23:56:35 +0800 MIME-Version: 1.0 In-Reply-To: <20151031135531.GD7865@thinpad.lan.raisama.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v6 08/33] exec: allow memory to be allocated from any kind of path List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Vladimir Sementsov-Ogievskiy , kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, imammedo@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, rth@twiddle.net On 10/31/2015 09:55 PM, Eduardo Habkost wrote: > On Sat, Oct 31, 2015 at 03:44:39PM +0800, Xiao Guangrong wrote: >> On 10/30/2015 10:04 PM, Vladimir Sementsov-Ogievskiy wrote: >>> On 30.10.2015 08:56, Xiao Guangrong wrote: >>>> Currently file_ram_alloc() is designed for hugetlbfs, however, the memory >>>> of nvdimm can come from either raw pmem device eg, /dev/pmem, or the file >>>> locates at DAX enabled filesystem >>>> >>>> So this patch let it work on any kind of path >>>> >>>> Signed-off-by: Xiao Guangrong > [...] >>>> - block->mr->align = hpagesize; >>>> - if (memory < hpagesize) { >>>> + if (pagesize == getpagesize()) { >>>> + fprintf(stderr, "Memory is not allocated from HugeTlbfs.\n"); >>>> + } >>> >>> It is strange to see this warning every time. >>> >>> Shouldn't the differentiation be done explicitly in command line? May be separate option mem-tlb, or >>> separate flag tlbfs=on, or for new feature - new option mem-file, or prefixes for paths (tlbfs://, >>> file://).. Or the other way to not mix things but split them. >> >> This is just a reminder to users. Currently Qemu do not stop user to append a regular file >> for its backend memory, particularly, hugetlbfs is not the only way to use HugePage for >> the THP-enabled system. >> >> We can implement your idea as a independent patchset in the future. > > Isn't the whole point of this patch to make the code not specific to > hugetlbfs anymore? It makes the warning obsolete. > Before this patchset, this warning still can be triggered, for example, we can specify the @path to /tmp/ I agree this warning could be improved, but let us do it independently.