From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Jan Beulich" <JBeulich@suse.com>
Subject: Re: [PATCH 1/8] x86/time: improve cross-CPU clock
 monotonicity (and more)
Date: Wed, 15 Jun 2016 04:32:05 -0600
Message-ID: <57614AC502000078000F53FD@prv-mh.provo.novell.com>
References: <576140F302000078000F52FE@prv-mh.provo.novell.com>
 <5761496802000078000F5395@prv-mh.provo.novell.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta3.messagelabs.com ([195.245.230.39])
 by lists.xenproject.org with esmtp (Exim 4.84_2)
 (envelope-from <JBeulich@suse.com>) id 1bD87E-0000Ra-Da
 for xen-devel@lists.xenproject.org; Wed, 15 Jun 2016 10:32:08 +0000
In-Reply-To: <5761496802000078000F5395@prv-mh.provo.novell.com>
Content-Disposition: inline
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
 <mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
 <mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Errors-To: xen-devel-bounces@lists.xen.org
Sender: "Xen-devel" <xen-devel-bounces@lists.xen.org>
To: xen-devel <xen-devel@lists.xenproject.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>, Dario Faggioli <dario.faggioli@citrix.com>, Joao Martins <joao.m.martins@oracle.com>
List-Id: xen-devel@lists.xenproject.org

Pj4+IE9uIDE1LjA2LjE2IGF0IDEyOjI2LCA8SkJldWxpY2hAc3VzZS5jb20+IHdyb3RlOgoKVGhl
IHRpdGxlIG9mIHRoaXMgd2FzIChvZiBjb3Vyc2UpIG1lYW50IHRvIGJlCgp4ODYvdGltZTogYWRq
dXN0IGxvY2FsIHN5c3RlbSB0aW1lIGluaXRpYWxpemF0aW9uCgpKYW4KCj4gVXNpbmcgdGhlIGJh
cmUgcmV0dXJuIHZhbHVlIGZyb20gcmVhZF9wbGF0Zm9ybV9zdGltZSgpIGlzIG5vdCBzdWl0YWJs
ZQo+IHdoZW4gbG9jYWxfdGltZV9jYWxpYnJhdGlvbigpIGlzIGdvaW5nIHRvIHVzZSBpdHMgZmFz
dCBwYXRoOiBEaXZlcmdlbmNlCj4gb2Ygc2V2ZXJhbCBkb3plbiBtaWNyb3NlY29uZHMgYmV0d2Vl
biBOT1coKSByZXR1cm4gdmFsdWVzIG9uIGRpZmZlcmVudAo+IENQVXMgcmVzdWx0cyB3aGVuIHBs
YXRmb3JtIGFuZCBsb2NhbCB0aW1lIGRvbid0IHN0YXkgaW4gY2xvc2Ugc3luYy4KPiAKPiBMYXRj
aCBsb2NhbCBhbmQgcGxhdGZvcm0gdGltZSBvbiB0aGUgQ1BVIGluaXRpYXRpbmcgQVAgYnJpbmd1
cCwgc3VjaAo+IHRoYXQgdGhlIEFQIGNhbiB1c2UgdGhlc2UgdmFsdWVzIHRvIHNlZWQgaXRzIHN0
aW1lX2xvY2FsX3N0YW1wIHdpdGggYXMKPiBsaXR0bGUgb2YgYW4gZXJyb3IgYXMgcG9zc2libGUu
IFRoZSBib290IENQVSwgb3RvaCwgY2FuIHNpbXBseQo+IGNhbGN1bGF0ZSB0aGUgY29ycmVjdCBp
bml0aWFsIHZhbHVlIChvdGhlciBDUFVzIGNvdWxkIGRvIHNvIHRvbyB3aXRoCj4gZXZlbiBncmVh
dGVyIGFjY3VyYWN5IHRoYW4gdGhlIGFwcHJvYWNoIGJlaW5nIGludHJvZHVjZWQsIGJ1dCB0aGF0
IGNhbgo+IHdvcmsgb25seSBpZiBhbGwgQ1BVcycgVFNDcyBzdGFydCB0aWNraW5nIGF0IHRoZSBz
YW1lIHRpbWUsIHdoaWNoCj4gZ2VuZXJhbGx5IGNhbid0IGJlIGFzc3VtZWQgdG8gYmUgdGhlIGNh
c2Ugb24gbXVsdGktc29ja2V0IHN5c3RlbXMpLgo+IAo+IFRoaXMgc2xpZ2h0bHkgZGVmZXJzIGlu
aXRfcGVyY3B1X3RpbWUoKSAobW92ZWQgYWhlYWQgYnkgY29tbWl0Cj4gZGQyNjU4Zjk2NiBbIng4
Ni90aW1lOiBpbml0aWFsaXNlIHRpbWUgZWFybGllciBkdXJpbmcKPiBzdGFydF9zZWNvbmRhcnko
KSJdKSBpbiBvcmRlciB0byByZWR1Y2UgYXMgbXVjaCBhcyBwb3NzaWJsZSB0aGUgZ2FwCj4gYmV0
d2VlbiBwb3B1bGF0aW5nIHRoZSBzdGFtcHMgYW5kIGNvbnN1bWluZyB0aGVtLgo+IAo+IFNpZ25l
ZC1vZmYtYnk6IEphbiBCZXVsaWNoIDxqYmV1bGljaEBzdXNlLmNvbT4KPiAKPiAtLS0gYS94ZW4v
YXJjaC94ODYvc21wYm9vdC5jCj4gKysrIGIveGVuL2FyY2gveDg2L3NtcGJvb3QuYwo+IEBAIC0z
MjgsMTIgKzMyOCwxMiBAQCB2b2lkIHN0YXJ0X3NlY29uZGFyeSh2b2lkICp1bnVzZWQpCj4gIAo+
ICAgICAgcGVyY3B1X3RyYXBzX2luaXQoKTsKPiAgCj4gLSAgICBpbml0X3BlcmNwdV90aW1lKCk7
Cj4gLQo+ICAgICAgY3B1X2luaXQoKTsKPiAgCj4gICAgICBzbXBfY2FsbGluKCk7Cj4gIAo+ICsg
ICAgaW5pdF9wZXJjcHVfdGltZSgpOwo+ICsKPiAgICAgIHNldHVwX3NlY29uZGFyeV9BUElDX2Ns
b2NrKCk7Cj4gIAo+ICAgICAgLyoKPiBAQCAtOTk2LDYgKzk5Niw4IEBAIGludCBfX2NwdV91cCh1
bnNpZ25lZCBpbnQgY3B1KQo+ICAgICAgaWYgKCAocmV0ID0gZG9fYm9vdF9jcHUoYXBpY2lkLCBj
cHUpKSAhPSAwICkKPiAgICAgICAgICByZXR1cm4gcmV0Owo+ICAKPiArICAgIHRpbWVfbGF0Y2hf
c3RhbXBzKCk7Cj4gKwo+ICAgICAgc2V0X2NwdV9zdGF0ZShDUFVfU1RBVEVfT05MSU5FKTsKPiAg
ICAgIHdoaWxlICggIWNwdV9vbmxpbmUoY3B1KSApCj4gICAgICB7Cj4gLS0tIGEveGVuL2FyY2gv
eDg2L3RpbWUuYwo+ICsrKyBiL3hlbi9hcmNoL3g4Ni90aW1lLmMKPiBAQCAtMTMyOCwyMSArMTMy
OCw1MSBAQCBzdGF0aWMgdm9pZCB0aW1lX2NhbGlicmF0aW9uKHZvaWQgKnVudXNlCj4gICAgICAg
ICAgICAgICAgICAgICAgICZyLCAxKTsKPiAgfQo+ICAKPiArc3RhdGljIHN0cnVjdCB7Cj4gKyAg
ICBzX3RpbWVfdCBsb2NhbF9zdGltZSwgbWFzdGVyX3N0aW1lOwo+ICt9IGFwX2JyaW5ndXBfcmVm
Owo+ICsKPiArdm9pZCB0aW1lX2xhdGNoX3N0YW1wcyh2b2lkKSB7Cj4gKyAgICB1bnNpZ25lZCBs
b25nIGZsYWdzOwo+ICsgICAgdTY0IHRzYzsKPiArCj4gKyAgICBsb2NhbF9pcnFfc2F2ZShmbGFn
cyk7Cj4gKyAgICBhcF9icmluZ3VwX3JlZi5tYXN0ZXJfc3RpbWUgPSByZWFkX3BsYXRmb3JtX3N0
aW1lKCk7Cj4gKyAgICB0c2MgPSByZHRzYygpOwo+ICsgICAgbG9jYWxfaXJxX3Jlc3RvcmUoZmxh
Z3MpOwo+ICsKPiArICAgIGFwX2JyaW5ndXBfcmVmLmxvY2FsX3N0aW1lID0gZ2V0X3NfdGltZV9m
aXhlZCh0c2MpOwo+ICt9Cj4gKwo+ICB2b2lkIGluaXRfcGVyY3B1X3RpbWUodm9pZCkKPiAgewo+
ICAgICAgc3RydWN0IGNwdV90aW1lICp0ID0gJnRoaXNfY3B1KGNwdV90aW1lKTsKPiAgICAgIHVu
c2lnbmVkIGxvbmcgZmxhZ3M7Cj4gKyAgICB1NjQgdHNjOwo+ICAgICAgc190aW1lX3Qgbm93Owo+
ICAKPiAgICAgIC8qIEluaXRpYWwgZXN0aW1hdGUgZm9yIFRTQyByYXRlLiAqLwo+ICAgICAgdC0+
dHNjX3NjYWxlID0gcGVyX2NwdShjcHVfdGltZSwgMCkudHNjX3NjYWxlOwo+ICAKPiAgICAgIGxv
Y2FsX2lycV9zYXZlKGZsYWdzKTsKPiAtICAgIHQtPmxvY2FsX3RzY19zdGFtcCA9IHJkdHNjKCk7
Cj4gICAgICBub3cgPSByZWFkX3BsYXRmb3JtX3N0aW1lKCk7Cj4gKyAgICB0c2MgPSByZHRzYygp
Owo+ICAgICAgbG9jYWxfaXJxX3Jlc3RvcmUoZmxhZ3MpOwo+ICAKPiAgICAgIHQtPnN0aW1lX21h
c3Rlcl9zdGFtcCA9IG5vdzsKPiArICAgIC8qCj4gKyAgICAgKiBUbyBhdm9pZCBhIGRpc2NvbnRp
bnVpdHkgKFRTQyBhbmQgcGxhdGZvcm0gY2xvY2sgY2FuJ3QgYmUgZXhwZWN0ZWQKPiArICAgICAq
IHRvIGJlIGluIHBlcmZlY3Qgc3luYyksIGluaXRpYWxpemF0aW9uIGhlcmUgbmVlZHMgdG8gbWF0
Y2ggdXAgd2l0aAo+ICsgICAgICogbG9jYWxfdGltZV9jYWxpYnJhdGlvbigpJ3MgZGVjaXNpb24g
d2hldGhlciB0byB1c2UgaXRzIGZhc3QgcGF0aC4KPiArICAgICAqLwo+ICsgICAgaWYgKCBib290
X2NwdV9oYXMoWDg2X0ZFQVRVUkVfQ09OU1RBTlRfVFNDKSApCj4gKyAgICB7Cj4gKyAgICAgICAg
aWYgKCBzeXN0ZW1fc3RhdGUgPCBTWVNfU1RBVEVfc21wX2Jvb3QgKQo+ICsgICAgICAgICAgICBu
b3cgPSBnZXRfc190aW1lX2ZpeGVkKHRzYyk7Cj4gKyAgICAgICAgZWxzZQo+ICsgICAgICAgICAg
ICBub3cgKz0gYXBfYnJpbmd1cF9yZWYubG9jYWxfc3RpbWUgLSBhcF9icmluZ3VwX3JlZi5tYXN0
ZXJfc3RpbWU7Cj4gKyAgICB9Cj4gKyAgICB0LT5sb2NhbF90c2Nfc3RhbXAgICAgPSB0c2M7Cj4g
ICAgICB0LT5zdGltZV9sb2NhbF9zdGFtcCAgPSBub3c7Cj4gIH0KPiAgCj4gLS0tIGEveGVuL2lu
Y2x1ZGUvYXNtLXg4Ni90aW1lLmgKPiArKysgYi94ZW4vaW5jbHVkZS9hc20teDg2L3RpbWUuaAo+
IEBAIC00MCw2ICs0MCw3IEBAIGludCB0aW1lX3N1c3BlbmQodm9pZCk7Cj4gIGludCB0aW1lX3Jl
c3VtZSh2b2lkKTsKPiAgCj4gIHZvaWQgaW5pdF9wZXJjcHVfdGltZSh2b2lkKTsKPiArdm9pZCB0
aW1lX2xhdGNoX3N0YW1wcyh2b2lkKTsKPiAgCj4gIHN0cnVjdCBpb3JlcTsKPiAgaW50IGh3ZG9t
X3BpdF9hY2Nlc3Moc3RydWN0IGlvcmVxICppb3JlcSk7CgoKCgpfX19fX19fX19fX19fX19fX19f
X19fX19fX19fX19fX19fX19fX19fX19fX19fXwpYZW4tZGV2ZWwgbWFpbGluZyBsaXN0Clhlbi1k
ZXZlbEBsaXN0cy54ZW4ub3JnCmh0dHA6Ly9saXN0cy54ZW4ub3JnL3hlbi1kZXZlbAo=