From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Peng Subject: Re: [PATCH v16 01/10] x86: add generic resource (e.g. MSR) access hypercall Date: Fri, 26 Sep 2014 16:58:20 +0800 Message-ID: <20140926085819.GE15318@pengc-linux> References: <1411640350-26155-1-git-send-email-chao.p.peng@linux.intel.com> <1411640350-26155-2-git-send-email-chao.p.peng@linux.intel.com> <542473B2.5040504@citrix.com> <54253FC5020000780003977A@mail.emea.novell.com> Reply-To: Chao Peng Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <54253FC5020000780003977A@mail.emea.novell.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: keir@xen.org, Ian.Campbell@citrix.com, stefano.stabellini@eu.citrix.com, George.Dunlap@eu.citrix.com, Andrew Cooper , Ian.Jackson@eu.citrix.com, xen-devel@lists.xen.org, dgdegra@tycho.nsa.gov List-Id: xen-devel@lists.xenproject.org On Fri, Sep 26, 2014 at 09:28:21AM +0100, Jan Beulich wrote: > >>> On 25.09.14 at 21:57, wrote: > > On a different note, you need to enforce a maximum resource_op.nr of > > something rather low to (16/32 perhaps?) to prevent a toolstack asking > > for 0xffffffff non-preemptible operations. > > I'd start out as low as we can, i.e. right now just 2 (write followed > by read). Any increase of the threshold will then need proper (and > trackable) reasoning. Agree, especially when we have xmalloc() here. > > Jan