From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v2 7/8] xen/x86: Use 2M superpages for text/data/bss mappings Date: Wed, 24 Feb 2016 13:23:06 +0000 Message-ID: <56CDAEBA.5010500@citrix.com> References: <1456245085-2302-1-git-send-email-andrew.cooper3@citrix.com> <1456245085-2302-8-git-send-email-andrew.cooper3@citrix.com> <56CDBB6C02000078000D5AB6@prv-mh.provo.novell.com> <56CDAE70.6070100@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56CDAE70.6070100@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Xen-devel List-Id: xen-devel@lists.xenproject.org On 24/02/16 13:21, Andrew Cooper wrote: > On 24/02/16 13:17, Jan Beulich wrote: >>>>> On 23.02.16 at 17:31, wrote: >>> This balloons the size of Xen in memory from 4.4MB to 8MB, because of the >>> required alignment adjustments. >> Interesting - on v1 it was 12Mb iirc, and aiui you folded just one >> pair of 2M pages, which would yield 10M now; did you perhaps >> not account for .text spanning 2 large pages, due to the 1M bias >> it starts at? But anyway... > The original 12 was me just counting 6 superpages. I forgot to account > for the 1 released back because of .init (which I suppose is now in the > following patch). That, combined with the alignment drop results in 4 > in-use superpages after boot. This is perhaps more clear given the debugging shown in the cover letter. ~Andrew