From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Slutz Subject: Re: [PATCH v5 03/17] xenctx: Add -n (--display-stack-pages) option to output larger stack Date: Mon, 24 Mar 2014 09:26:06 -0400 Message-ID: <5330326E.3080909@terremark.com> References: <1395342425-16260-1-git-send-email-dslutz@verizon.com> <1395342425-16260-4-git-send-email-dslutz@verizon.com> <1395412141.19839.105.camel@kazak.uk.xensource.com> <532DF773.4050103@terremark.com> <1395657588.19365.31.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1395657588.19365.31.camel@kazak.uk.xensource.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: Ian Campbell , Don Slutz Cc: Stefano Stabellini , George Dunlap , Don Slutz , Ian Jackson , xen-devel@lists.xen.org, Jan Beulich List-Id: xen-devel@lists.xenproject.org On 03/24/14 06:39, Ian Campbell wrote: > On Sat, 2014-03-22 at 16:49 -0400, Don Slutz wrote: >> As you can see from above, only the last 3 lines show up for "-n 3" > OK. > >>> Why is the SP moving around in these pictures? I understood that this >>> option was changing what was considered to be the limit of the stack, >>> not the stack pointer itself, so shouldn't it be the base of the stack >>> which is moving around? >> These are pictures of the same stack at 3 different times. And as you >> can see >> from above, this option does change the stack limit. > There was no stack limit shown on your diagrams, only a stack pointer > which was mysteriously changing. The SP is an actual register which is a > property of the VM, changing it based on a xenctx surely doesn't make > sense! (also it is not moving by page sized increments, which is odd > even for the base, which ought to point at a page boundary surely). > >>> Perhaps if you had the diagram once and along side it had columns >>> showing what is printed for each -n value as a range >>> >>> e.g. >>> None -n 1 >>> +------------------+ + >>> | | | >>> | | | >>> | | | >>> | | | >>> | | | >>> +------------------+ + | >>> | | | | >>> SP --> | | + + >>> | | >>> | | >>> | | >>> +------------------+ >>> >>> (or whatever the reality is) >>> >>> [...] >> I will add this. And some statement about each picture is for a >> different time. > Wait, what? Each picture is for a different time? How is that useful? > > The point of these diagrams is surely to illustrate the effect of what > using this option would be at some fixed "snapshot" in time, adding a > second axis of variation to the pictures is just confusing. > > Ian. > Ok, will adjust to just 1 picture. -Don Slutz