From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0.aculab.com (mx0.aculab.com [213.249.233.131]) by lists.ozlabs.org (Postfix) with SMTP id 63A051A00F4 for ; Fri, 5 Sep 2014 18:31:22 +1000 (EST) Received: from mx0.aculab.com ([127.0.0.1]) by localhost (mx0.aculab.com [127.0.0.1]) (amavisd-new, port 10024) with SMTP id 07034-09 for ; Fri, 5 Sep 2014 09:31:18 +0100 (BST) From: David Laight To: "'paulmck@linux.vnet.ibm.com'" , Peter Hurley Subject: RE: bit fields && data tearing Date: Fri, 5 Sep 2014 08:30:03 +0000 Message-ID: <063D6719AE5E284EB5DD2968C1650D6D17487F66@AcuExch.aculab.com> References: <54079B70.4050200@hurleysoftware.com> <1409785893.30640.118.camel@pasglop> <21512.10628.412205.873477@gargle.gargle.HOWL> <20140904090952.GW17454@tucnak.redhat.com> <540859EC.5000407@hurleysoftware.com> <20140904175044.4697aee4@alan.etchedpixels.co.uk> <5408C0AB.6050801@hurleysoftware.com> <20140905001751.GL5001@linux.vnet.ibm.com> <1409883098.5078.14.camel@jarvis.lan> <5409243C.4080704@hurleysoftware.com> <20140905040645.GO5001@linux.vnet.ibm.com> In-Reply-To: <20140905040645.GO5001@linux.vnet.ibm.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Cc: Jakub Jelinek , One Thousand Gnomes , Tony Luck , "linux-ia64@vger.kernel.org" , Mikael Pettersson , "H. Peter Anvin" , Oleg Nesterov , "linux-kernel@vger.kernel.org" , James Bottomley , Paul Mackerras , "linux-arch@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , Miroslav Franc , Richard Henderson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , RnJvbTogUGF1bCBFLiBNY0tlbm5leQ0KPiBPbiBUaHUsIFNlcCAwNCwgMjAxNCBhdCAxMDo0Nzoy NFBNIC0wNDAwLCBQZXRlciBIdXJsZXkgd3JvdGU6DQo+ID4gSGkgSmFtZXMsDQo+ID4NCj4gPiBP biAwOS8wNC8yMDE0IDEwOjExIFBNLCBKYW1lcyBCb3R0b21sZXkgd3JvdGU6DQo+ID4gPiBPbiBU aHUsIDIwMTQtMDktMDQgYXQgMTc6MTcgLTA3MDAsIFBhdWwgRS4gTWNLZW5uZXkgd3JvdGU6DQo+ ID4gPj4gK0FuZCB0aGVyZSBhcmUgYW50aS1ndWFyYW50ZWVzOg0KPiA+ID4+ICsNCj4gPiA+PiAr ICgqKSBUaGVzZSBndWFyYW50ZWVzIGRvIG5vdCBhcHBseSB0byBiaXRmaWVsZHMsIGJlY2F1c2Ug Y29tcGlsZXJzIG9mdGVuDQo+ID4gPj4gKyAgICAgZ2VuZXJhdGUgY29kZSB0byBtb2RpZnkgdGhl c2UgdXNpbmcgbm9uLWF0b21pYyByZWFkLW1vZGlmeS13cml0ZQ0KPiA+ID4+ICsgICAgIHNlcXVl bmNlcy4gIERvIG5vdCBhdHRlbXB0IHRvIHVzZSBiaXRmaWVsZHMgdG8gc3luY2hyb25pemUgcGFy YWxsZWwNCj4gPiA+PiArICAgICBhbGdvcml0aG1zLg0KPiA+ID4+ICsNCj4gPiA+PiArICgqKSBF dmVuIGluIGNhc2VzIHdoZXJlIGJpdGZpZWxkcyBhcmUgcHJvdGVjdGVkIGJ5IGxvY2tzLCBhbGwg ZmllbGRzDQo+ID4gPj4gKyAgICAgaW4gYSBnaXZlbiBiaXRmaWVsZCBtdXN0IGJlIHByb3RlY3Rl ZCBieSBvbmUgbG9jay4gIElmIHR3byBmaWVsZHMNCj4gPiA+PiArICAgICBpbiBhIGdpdmVuIGJp dGZpZWxkIGFyZSBwcm90ZWN0ZWQgYnkgZGlmZmVyZW50IGxvY2tzLCB0aGUgY29tcGlsZXIncw0K PiA+ID4+ICsgICAgIG5vbi1hdG9taWMgcmVhZC1tb2RpZnktd3JpdGUgc2VxdWVuY2VzIGNhbiBj YXVzZSBhbiB1cGRhdGUgdG8gb25lDQo+ID4gPj4gKyAgICAgZmllbGQgdG8gY29ycnVwdCB0aGUg dmFsdWUgb2YgYW4gYWRqYWNlbnQgZmllbGQuDQo+ID4gPj4gKw0KPiA+ID4+ICsgKCopIFRoZXNl IGd1YXJhbnRlZXMgYXBwbHkgb25seSB0byBwcm9wZXJseSBhbGlnbmVkIGFuZCBzaXplZCBzY2Fs YXINCj4gPiA+PiArICAgICB2YXJpYWJsZXMuICAiUHJvcGVybHkgc2l6ZWQiIGN1cnJlbnRseSBt ZWFucyAiaW50IiBhbmQgImxvbmciLA0KPiA+ID4+ICsgICAgIGJlY2F1c2Ugc29tZSBDUFUgZmFt aWxpZXMgZG8gbm90IHN1cHBvcnQgbG9hZHMgYW5kIHN0b3JlcyBvZg0KPiA+ID4+ICsgICAgIG90 aGVyIHNpemVzLiAgKCJTb21lIENQVSBmYW1pbGllcyIgaXMgY3VycmVudGx5IGJlbGlldmVkIHRv DQo+ID4gPj4gKyAgICAgYmUgb25seSBBbHBoYSAyMTA2NC4gIElmIHRoaXMgaXMgYWN0dWFsbHkg dGhlIGNhc2UsIGEgZGlmZmVyZW50DQo+ID4gPj4gKyAgICAgbm9uLWd1YXJhbnRlZSBpcyBsaWtl bHkgdG8gYmUgZm9ybXVsYXRlZC4pDQo+ID4gPg0KPiA+ID4gVGhpcyBpcyBhIGJpdCB1bmNsZWFy LiAgUHJlc3VtYWJseSB5b3UncmUgdGFsa2luZyBhYm91dCBkZWZpbml0ZW5lc3Mgb2YNCj4gPiA+ IHRoZSBvdXRjb21lIChhcyBpbiB3aGF0J3Mgc2VlbiBhZnRlciBtdWx0aXBsZSBzdG9yZXMgdG8g dGhlIHNhbWUNCj4gPiA+IHZhcmlhYmxlKS4NCj4gPg0KPiA+IE5vLCB0aGUgbGFzdCBjb25kaXRp b25zIHJlZmVycyB0byBhZGphY2VudCBieXRlIHN0b3JlcyBmcm9tIGRpZmZlcmVudA0KPiA+IGNw dSBjb250ZXh0cyAoZWl0aGVyIGludGVycnVwdCBvciBTTVApLg0KPiA+DQo+ID4gPiBUaGUgZ3Vh cmFudGVlcyBhcmUgb25seSBmb3IgbmF0dXJhbCB3aWR0aCBvbiBQYXJpc2MgYXMgd2VsbCwNCj4g PiA+IHNvIHlvdSB3b3VsZCBnZXQgYSBtZXNzIGlmIHlvdSBkaWQgYnl0ZSBzdG9yZXMgdG8gYWRq YWNlbnQgbWVtb3J5DQo+ID4gPiBsb2NhdGlvbnMuDQo+ID4NCj4gPiBGb3IgYSBzaW1wbGUgdGVz dCBsaWtlOg0KPiA+DQo+ID4gc3RydWN0IHggew0KPiA+IAlsb25nIGE7DQo+ID4gCWNoYXIgYjsN Cj4gPiAJY2hhciBjOw0KPiA+IAljaGFyIGQ7DQo+ID4gCWNoYXIgZTsNCj4gPiB9Ow0KPiA+DQo+ ID4gdm9pZCBzdG9yZV9iYyhzdHJ1Y3QgeCAqcCkgew0KPiA+IAlwLT5iID0gMTsNCj4gPiAJcC0+ YyA9IDI7DQo+ID4gfQ0KPiA+DQo+ID4gb24gcGFyaXNjLCBnY2MgZ2VuZXJhdGVzIHNlcGFyYXRl IGJ5dGUgc3RvcmVzDQo+ID4NCj4gPiB2b2lkIHN0b3JlX2JjKHN0cnVjdCB4ICpwKSB7DQo+ID4g ICAgMDoJMzQgMWMgMDAgMDIgCWxkaSAxLHJldDANCj4gPiAgICA0OgkwZiA1YyAxMiAwOCAJc3Ri IHJldDAsNChyMjYpDQo+ID4gICAgODoJMzQgMWMgMDAgMDQgCWxkaSAyLHJldDANCj4gPiAgICBj OgllOCA0MCBjMCAwMCAJYnYgcjAocnApDQo+ID4gICAxMDoJMGYgNWMgMTIgMGEgCXN0YiByZXQw LDUocjI2KQ0KPiA+DQo+ID4gd2hpY2ggYXBwZWFycyB0byBjb25maXJtIHRoYXQgb24gcGFyaXNj IGFkamFjZW50IGJ5dGUgZGF0YQ0KPiA+IGlzIHNhZmUgZnJvbSBjb3JydXB0aW9uIGJ5IGNvbmN1 cnJlbnQgY3B1IHVwZGF0ZXM7IHRoYXQgaXMsDQo+ID4NCj4gPiBDUFUgMCAgICAgICAgICAgICAg ICB8IENQVSAxDQo+ID4gICAgICAgICAgICAgICAgICAgICAgfA0KPiA+IHAtPmIgPSAxICAgICAg ICAgICAgIHwgcC0+YyA9IDINCj4gPiAgICAgICAgICAgICAgICAgICAgICB8DQo+ID4NCj4gPiB3 aWxsIHJlc3VsdCBpbiBwLT5iID09IDEgJiYgcC0+YyA9PSAyIChhc3N1bWUgYm90aCB2YWx1ZXMN Cj4gPiB3ZXJlIDAgYmVmb3JlIHRoZSBjYWxsIHRvIHN0b3JlX2JjKCkpLg0KPiANCj4gV2hhdCBQ ZXRlciBzYWlkLiAgSSB3b3VsZCBhc2sgZm9yIHN1Z2dlc3Rpb25zIGZvciBiZXR0ZXIgd29yZGlu ZywgYnV0DQo+IEkgd291bGQgbXVjaCByYXRoZXIgYmUgYWJsZSB0byBzYXkgdGhhdCBzaW5nbGUt Ynl0ZSByZWFkcyBhbmQgd3JpdGVzDQo+IGFyZSBhdG9taWMgYW5kIHRoYXQgYWxpZ25lZC1zaG9y dCByZWFkcyBhbmQgd3JpdGVzIGFyZSBhbHNvIGF0b21pYy4NCj4gDQo+IFRodXMgZmFyLCBpdCBs b29rcyBsaWtlIHdlIGxvc2Ugb25seSB2ZXJ5IG9sZCBBbHBoYSBzeXN0ZW1zLCBzbyB1bmxlc3MN Cj4gSSBoZWFyIG90aGVyd2lzZSwgSSB1cGRhdGUgbXkgcGF0Y2ggdG8gb3V0bGF3IHRoZXNlIHZl cnkgb2xkIHN5c3RlbXMuDQoNClBlb3BsZSB3aXRoIG9sZCBBbHBoYXMgY2FuIHJ1biBOZXRCU0Qg aW5zdGVhZCwgYWxvbmcgd2l0aCB0aG9zZSB3aG8gaGF2ZSByZWFsIFZBWGVuIDotKQ0KDQpJJ3Zl IHNlZW4gZ2NjIGdlbmVyYXRlIDMyYml0IGFjY2Vzc2VzIGZvciAxNmJpdCBzdHJ1Y3R1cmUgbWVt YmVycyBvbiBhcm0uDQpJdCBkb2VzIHRoaXMgYmVjYXVzZSBvZiB0aGUgbW9yZSBsaW1pdGVkIHJh bmdlIG9mIHRoZSBvZmZzZXRzIGZvciB0aGUgMTZiaXQgYWNjZXNzLg0KT1RPSCBJIGRvbid0IGtu b3cgaWYgaXQgZXZlciBkaWQgdGhpcyBmb3Igd3JpdGVzIC0gc28gaXQgbWF5IGJlIG1vb3QuDQoN CglEYXZpZA0KDQo=