From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joao Martins Subject: Re: [PATCH 1/8] x86/time: improve cross-CPU clock monotonicity (and more) Date: Tue, 21 Jun 2016 14:57:00 +0100 Message-ID: <576947AC.4040904@oracle.com> References: <576140F302000078000F52FE@prv-mh.provo.novell.com> <5761496802000078000F5395@prv-mh.provo.novell.com> <5761DC0E.5010201@oracle.com> <57627F0702000078000F590A@prv-mh.provo.novell.com> <57630BA4.30607@oracle.com> <5763C3A502000078000F5E97@prv-mh.provo.novell.com> <57692D7A.6010704@oracle.com> <57694EF502000078000F735A@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bFM9y-0000Jx-MG for xen-devel@lists.xenproject.org; Tue, 21 Jun 2016 13:56:10 +0000 In-Reply-To: <57694EF502000078000F735A@prv-mh.provo.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Jan Beulich Cc: Andrew Cooper , Dario Faggioli , xen-devel List-Id: xen-devel@lists.xenproject.org CgpPbiAwNi8yMS8yMDE2IDAxOjI4IFBNLCBKYW4gQmV1bGljaCB3cm90ZToKPj4+PiBPbiAyMS4w Ni4xNiBhdCAxNDowNSwgPGpvYW8ubS5tYXJ0aW5zQG9yYWNsZS5jb20+IHdyb3RlOgo+IAo+Pgo+ PiBPbiAwNi8xNy8yMDE2IDA4OjMyIEFNLCBKYW4gQmV1bGljaCB3cm90ZToKPj4+Pj4+IE9uIDE2 LjA2LjE2IGF0IDIyOjI3LCA8am9hby5tLm1hcnRpbnNAb3JhY2xlLmNvbT4gd3JvdGU6Cj4+Pj4+ IEkuZS4gbXkgcGxhbiB3YXMsIG9uY2UgdGhlIGJhY2t3YXJkcyBtb3ZlcyBhcmUgc21hbGwgZW5v dWdoLCB0byBtYXliZQo+Pj4+PiBpbmRlZWQgY29tcGVuc2F0ZSB0aGVtIGJ5IG1haW50YWluaW5n IGEgZ2xvYmFsIHZhcmlhYmxlIHRyYWNraW5nCj4+Pj4+IHRoZSBtb3N0IHJlY2VudGx5IHJldHVy bmVkIHZhbHVlLiBUaGVyZSBhcmUgaXNzdWVzIHdpdGggc3VjaCBhbgo+Pj4+PiBhcHByb2FjaCB0 b28sIHRob3VnaDogSFQgZWZmZWN0cyBjYW4gcmVzdWx0IGluIG9uZSBoeXBlcnRocmVhZAo+Pj4+ PiBtYWtpbmcgaXQganVzdCBwYXN0IHRoYXQgY2hlY2sgb2YgdGhlIGdsb2JhbCwgdGhlbiBoYXJk d2FyZQo+Pj4+PiBzd2l0Y2hpbmcgdG8gdGhlIG90aGVyIGh5cGVydGhyZWFkLCBOT1coKSBwcm9k dWNpbmcgYSBzbGlnaHRseQo+Pj4+PiBsYXJnZXIgdmFsdWUgdGhlcmUsIGFuZCBoYXJkd2FyZSBz d2l0Y2hpbmcgYmFjayB0byB0aGUgZmlyc3QKPj4+Pj4gaHlwZXJ0aHJlYWQgb25seSBhZnRlciB0 aGUgc2Vjb25kIG9uZSBjb25zdW1lZCB0aGUgcmVzdWx0IG9mCj4+Pj4+IE5PVygpLiBEYXJpbydz IHVzZSB3b3VsZCBiZSB1bmFmZmVjdGVkIGJ5IHRoaXMgYWl1aSwgYXMgaGlzIE5PVygpCj4+Pj4+ IGludm9jYXRpb25zIGFyZSBnbG9iYWxseSBzZXJpYWxpemVkIHRocm91Z2ggYSBzcGlubG9jaywg YnV0IGFyYml0cmFyeQo+Pj4+PiBOT1coKSBpbnZvY2F0aW9ucyBvbiB0d28gaHlwZXJ0aHJlYWRz IGNhbid0IGJlIG1hZGUgc3VjaCB0aGF0Cj4+Pj4+IHRoZSBpbnZva2luZyBwYXJ0eSBjYW4gYmUg Z3VhcmFudGVlZCB0byBzZWUgc3RyaWN0bHkgbW9udG9uaWMKPj4+Pj4gdmFsdWVzLgo+Pj4+Pgo+ Pj4+PiBBbmQgYnR3Liwgc2ltaWxhciBjb25zaWRlcmF0aW9ucyBhcHBseSBmb3IgdHdvIGZ1bGx5 IGluZGVwZW5kZW50Cj4+Pj4+IENQVXMsIGlmIG9uZSBydW5zIGF0IGEgbXVjaCBoaWdoZXIgUC1z dGF0ZSB0aGFuIHRoZSBvdGhlciAoaS5lLgo+Pj4+PiB0aGUgZmFzdGVyIG9uZSBjb3VsZCBvdmVy dGFrZSB0aGUgc2xvd2VyIG9uZSBiZXR3ZWVuIHRoZQo+Pj4+PiBtb250b25pY2l0eSBjaGVjayBp biBOT1coKSBhbmQgdGhlIGNhbGxlcnMgY29uc3VtaW5nIHRoZSByZXR1cm5lZAo+Pj4+PiB2YWx1 ZXMpLiBTbyBpbiB0aGUgZW5kIEknbSBub3Qgc3VyZSBpdCdzIHdvcnRoIHRoZSBwZXJmb3JtYW5j ZSBoaXQKPj4+Pj4gc3VjaCBhIGdsb2JhbCBtb250b25pY2l0eSBjaGVjayB3b3VsZCBpbmN1ciwg YW5kIHRoZXJlZm9yZSBJIGRpZG4ndAo+Pj4+PiBtYWtlIGEgcmVzcGVjdGl2ZSBwYXRjaCBwYXJ0 IG9mIHRoaXMgc2VyaWVzLgo+Pj4+Pgo+Pj4+Cj4+Pj4gSG0sIGd1ZXN0cyBwdmNsb2NrIHNob3Vs ZCBoYXZlIGZhY2VkIHNpbWlsYXIgaXNzdWVzIHRvbyBhcyB0aGVpcgo+Pj4+IGxvY2FsIHN0YW1w cyBmb3IgZWFjaCB2Y3B1IGRpdmVyZ2UuIExpbnV4IGNvbW1pdCA0ODlmYjQ5ICgieDg2LCBwYXJh dmlydDogCj4+Pj4gQWRkIGEKPj4+PiBnbG9iYWwgc3luY2hyb25pemF0aW9uIHBvaW50IGZvciBw dmNsb2NrIikgZGVwaWN0cyBhIGZpeCB0byBzaW1pbGFyIAo+Pj4+IHNpdHVhdGlvbnMgdG8gdGhl Cj4+Pj4gc2NlbmFyaW9zIHlvdSBqdXN0IGRlc2NyaWJlZCAtIHdoaWNoIGxlYWQgdG8gaGF2ZSBh IGdsb2JhbCB2YXJpYWJsZSB0byBrZWVwIAo+Pj4+IHRyYWNrIG9mCj4+Pj4gbW9zdCByZWNlbnQg dGltZXN0YW1wLiBPbmUgaW1wb3J0YW50IGNodW5rIG9mIHRoYXQgY29tbWl0IGlzIHBhc3RlZCBi ZWxvdyAKPj4+PiBmb3IKPj4+PiBjb252ZW5pZW5jZToKPj4+Pgo+Pj4+IC0tCj4+Pj4gLyoKPj4+ PiAgKiBBc3N1bXB0aW9uIGhlcmUgaXMgdGhhdCBsYXN0X3ZhbHVlLCBhIGdsb2JhbCBhY2N1bXVs YXRvciwgYWx3YXlzIGdvZXMKPj4+PiAgKiBmb3J3YXJkLiBJZiB3ZSBhcmUgbGVzcyB0aGFuIHRo YXQsIHdlIHNob3VsZCBub3QgYmUgbXVjaCBzbWFsbGVyLgo+Pj4+ICAqIFdlIGFzc3VtZSB0aGVy ZSBpcyBhbiBlcnJvciBtYXJnaW5nIHdlJ3JlIGluc2lkZSwgYW5kIHRoZW4gdGhlIGNvcnJlY3Rp b24KPj4+PiAgKiBkb2VzIG5vdCBzYWNyaWZpY2UgYWNjdXJhY3kuCj4+Pj4gICoKPj4+PiAgKiBG b3IgcmVhZHM6IGdsb2JhbCBtYXkgaGF2ZSBjaGFuZ2VkIGJldHdlZW4gdGVzdCBhbmQgcmV0dXJu LAo+Pj4+ICAqIGJ1dCB0aGlzIG1lYW5zIHNvbWVvbmUgZWxzZSB1cGRhdGVkIHBva2VkIHRoZSBj bG9jayBhdCBhIGxhdGVyIHRpbWUuCj4+Pj4gICogV2UganVzdCBuZWVkIHRvIG1ha2Ugc3VyZSB3 ZSBhcmUgbm90IHNlZWluZyBhIGJhY2t3YXJkcyBldmVudC4KPj4+PiAgKgo+Pj4+ICAqIEZvciB1 cGRhdGVzOiBsYXN0X3ZhbHVlID0gcmV0IGlzIG5vdCBlbm91Z2gsIHNpbmNlIHR3byB2Y3B1cyBj b3VsZCBiZQo+Pj4+ICAqIHVwZGF0aW5nIGF0IHRoZSBzYW1lIHRpbWUsIGFuZCBvbmUgb2YgdGhl bSBjb3VsZCBiZSBzbGlnaHRseSBiZWhpbmQsCj4+Pj4gICogbWFraW5nIHRoZSBhc3N1bXB0aW9u IHRoYXQgbGFzdF92YWx1ZSBhbHdheXMgZ28gZm9yd2FyZCBmYWlsIHRvIGhvbGQuCj4+Pj4gICov Cj4+Pj4gIGxhc3QgPSBhdG9taWM2NF9yZWFkKCZsYXN0X3ZhbHVlKTsKPj4+PiAgZG8gewo+Pj4+ ICAgICAgaWYgKHJldCA8IGxhc3QpCj4+Pj4gICAgICAgICAgcmV0dXJuIGxhc3Q7Cj4+Pj4gICAg ICBsYXN0ID0gYXRvbWljNjRfY21weGNoZygmbGFzdF92YWx1ZSwgbGFzdCwgcmV0KTsKPj4+PiAg fSB3aGlsZSAodW5saWtlbHkobGFzdCAhPSByZXQpKTsKPj4+PiAtLQo+Pj4KPj4+IE1lYW5pbmcg dGhleSBkZWNpZGVkIGl0J3Mgd29ydGggdGhlIG92ZXJoZWFkLiBCdXQgKGhhdmluZyByZWFkCj4+ PiB0aHJvdWdoIHRoZSBlbnRpcmUgZGVzY3JpcHRpb24pIHRoZXkgZG9uJ3QgZXZlbiBkaXNjdXNz IHdoZXRoZXIgdGhpcwo+Pj4gaW5kZWVkIGVsaW1pbmF0ZXMgX2FsbF8gYXBwYXJlbnQgYmFja3dh cmQgbW92ZXMgZHVlIHRvIGVmZmVjdHMKPj4+IGxpa2UgdGhlIG9uZXMgbmFtZWQgYWJvdmUuCj4+ Pgo+Pj4gUGx1cywgdGhlIGNvbnRlbnRpb24gdGhleSdyZSBmYWNpbmcgaXMgbGltaXRlZCB0byBh IHNpbmdsZSBWTSwgaS5lLiBsaWtlbHkKPj4+IG11Y2ggbW9yZSBuYXJyb3cgdGhhbiB0aGF0IG9u IGFuIGVudGlyZSBwaHlzaWNhbCBzeXN0ZW0uIFNvIGZvcgo+Pj4gdXMgdG8gZG8gdGhlIHNhbWUg aW4gdGhlIGh5cGVydmlzb3IsIHF1aXRlIGEgYml0IG1vcmUgb2Ygd2luIHdvdWxkCj4+PiBiZSBu ZWVkZWQgdG8gb3V0d2VpZ2ggdGhlIGNvc3QuCj4+Pgo+PiBFeHBlcmltZW50YWwgZGV0YWlscyBs b29rIHZlcnkgdW5jbGVhciB0b28gLSBsaWtlbHkgcnVubmluZyB0aGUgdGltZQo+PiB3YXJwIHRl c3QgZm9yIDUgZGF5cyB3b3VsZCBnZXQgc29tZSBvZiB0aGVzZSBjYXNlcyBjbGVhcmVkIG91dC4g QnV0Cj4+IGFzIHlvdSBzYXkgaXQgc2hvdWxkIGJlIG11Y2ggbW9yZSBuYXJyb3cgdGhhdCBvZiBh biBlbnRpcmUgc3lzdGVtLgo+Pgo+PiBCVFcgSXQgd2FzIGltcGxpY2l0IGluIHRoZSBkaXNjdXNz aW9uIGJ1dCBteSBhcG9sb2dpZXMgZm9yIG5vdAo+PiBmb3JtYWxseS9leHBsaWNpdGx5IHN0YXRp bmcuIFNvIEZXSVc6Cj4+Cj4+IFRlc3RlZC1ieTogSm9hbyBNYXJ0aW5zIDxqb2FvLm0ubWFydGlu c0BvcmFjbGUuY29tPgo+IAo+IFRoYW5rcywgYnV0IHRoaXMgLi4uCj4gCj4+IFRoaXMgc2VyaWVz IGlzIGNlcnRhaW5seSBhIHdheSBmb3J3YXJkIGludG8gaW1wcm92aW5nIGNyb3NzLUNQVSBtb25v dG9uaWNpdHksCj4+IGFuZCBJIGFtIHNlZWluZyBpbmRlZWQgbGVzcyBvY2N1cnJlbmNlcyBvZiB0 aW1lIGdvaW5nIGJhY2t3YXJkcyBvbiBteSAKPj4gc3lzdGVtcy4KPiAKPiAuLi4gbGVhdmVzIG1l IGd1ZXNzaW5nIHdoZXRoZXIgdGhlIGFib3ZlIHdhcyBtZWFudCBmb3IganVzdCB0aGlzCj4gcGF0 Y2gsIG9yIHRoZSBlbnRpcmUgc2VyaWVzLgo+IApBaCBzb3JyeSwgYSBsaXR0bGUgYW1iaWd1b3Vz IG9uIG15IGVuZCAtIEl0IGlzIG1lYW50IGZvciB0aGUgZW50aXJlIHNlcmllcy4KCkpvYW8KCl9f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClhlbi1kZXZlbCBt YWlsaW5nIGxpc3QKWGVuLWRldmVsQGxpc3RzLnhlbi5vcmcKaHR0cDovL2xpc3RzLnhlbi5vcmcv eGVuLWRldmVsCg==