From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Hellstrom Subject: Re: [PATCH 1/2] locking: Implement an algorithm choice for Wound-Wait mutexes Date: Thu, 14 Jun 2018 13:48:39 +0200 Message-ID: References: <20180613074745.14750-1-thellstrom@vmware.com> <20180613074745.14750-2-thellstrom@vmware.com> <20180613095012.GW12198@hirez.programming.kicks-ass.net> <69f3dee9-4782-bc90-3ee2-813ac6835c4a@vmware.com> <20180613131000.GX12198@hirez.programming.kicks-ass.net> <9afd482d-7082-fa17-5e34-179a652376e5@vmware.com> <20180614105151.GY12198@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Return-path: Received: from NAM01-SN1-obe.outbound.protection.outlook.com (mail-sn1nam01on0069.outbound.protection.outlook.com [104.47.32.69]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5DDEB6E744 for ; Thu, 14 Jun 2018 11:49:00 +0000 (UTC) In-Reply-To: <20180614105151.GY12198@hirez.programming.kicks-ass.net> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Peter Zijlstra Cc: Kate Stewart , Davidlohr Bueso , Jonathan Corbet , David Airlie , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Josh Triplett , linaro-mm-sig@lists.linaro.org, Greg Kroah-Hartman , Ingo Molnar , Philippe Ombredanne , Thomas Gleixner , "Paul E. McKenney" , linux-media@vger.kernel.org List-Id: dri-devel@lists.freedesktop.org T24gMDYvMTQvMjAxOCAxMjo1MSBQTSwgUGV0ZXIgWmlqbHN0cmEgd3JvdGU6Cj4gT24gV2VkLCBK dW4gMTMsIDIwMTggYXQgMDQ6MDU6NDNQTSArMDIwMCwgVGhvbWFzIEhlbGxzdHJvbSB3cm90ZToK Pj4gSW4gc2hvcnQsIHdpdGggV2FpdC1EaWUgKGJlZm9yZSB0aGUgcGF0Y2gpIGl0J3MgdGhlIHBy b2Nlc3MgX3Rha2luZ18gdGhlCj4+IGNvbnRlbmRlZCBsb2NrIHRoYXQgYmFja3Mgb2ZmIGlmIG5l Y2Vzc2FyeS4gTm8gcHJlZW1wdGlvbiByZXF1aXJlZC4gV2l0aAo+PiBXb3VuZC1XYWl0LCBpdCdz IHRoZSBwcm9jZXNzIF9ob2xkaW5nXyB0aGUgY29udGVuZGVkIGxvY2sgdGhhdCBnZXRzIHdvdW5k ZWQKPj4gKHByZWVtcHRlZCksIGFuZCBpdCBuZWVkcyB0byBiYWNrIG9mZiBhdCBpdHMgb3duIGRp c2NyZXRpb24gYnV0IG5vIGxhdGVyCj4+IHRoYW4gd2hlbiBpdCdzIGdvaW5nIHRvIHNsZWVwIG9u IGFub3RoZXIgd3cgbXV0ZXguIFRoYXQgcG9pbnQgaXMgd2hlcmUgd2UKPj4gaW50ZXJjZXB0IHRo ZSBwcmVlbXB0aW9uIHJlcXVlc3QuIFdlJ3JlIHByZWVtcHRpbmcgdGhlIHRyYW5zYWN0aW9uIHJh dGhlcgo+PiB0aGFuIHRoZSBwcm9jZXNzLgo+IFRoaXM6Cj4KPiAgICBXYWl0LWRpZToKPiAgICAg IFRoZSBuZXdlciB0cmFuc2FjdGlvbnMgYXJlIGtpbGxlZCB3aGVuOgo+ICAgICAgICBJdCAoPSB0 aGUgbmV3ZXIgdHJhbnNhY3Rpb24pIG1ha2VzIGEgcmVxZXVzdCBmb3IgYSBsb2NrIGJlaW5nIGhl bGQKPiAgICAgICAgYnkgYW4gb2xkZXIgdHJhbnNhY3Rpb25zCj4KPiAgICBXb3VuZC13YWl0Ogo+ ICAgICAgVGhlIG5ld2VyIHRyYW5zYWN0aW9ucyBhcmUga2lsbGVkIHdoZW46Cj4gICAgICAgIEFu IG9sZGVyIHRyYW5zYWN0aW9uIG1ha2VzIGEgcmVxdWVzdCBmb3IgYSBsb2NrIGJlaW5nIGhlbGQg YnkgdGhlCj4gICAgICAgIG5ld2VyIHRyYW5zYWN0aW9ucwo+Cj4gV291bGQgbWFrZSBmb3IgYW4g ZXhjZWxsZW50IGNvbW1lbnQgc29tZXdoZXJlLiBObyB0YWxraW5nIGFib3V0Cj4gcHJlZW1wdGlv biwgYWx0aG91Z2ggSSB0aGluayBJIGtub3cgd2hhdCB5b3UgbWVhbiB3aXRoIGl0LCB0aGF0IGlz IG5vdAo+IGhvdyBwcmVlbXB0aW9uIGlzIG5vcm1hbGx5IHVzZWQuCgpPay4gSSdsbCBpbmNvcnBv cmF0ZSBzb21ldGhpbmcgYWxvbmcgdGhpcyBsaW5lLiBVbmZvcnR1bmF0ZWx5IHRoYXQgbGFzdCAK c3RhdGVtZW50IGlzIG5vdCBmdWxseSB0cnVlLiBJdCBzaG91bGQgcmVhZAoiVGhlIG5ld2VyIHRy YW5zYWN0aW9ucyBhcmUgd291bmRlZCB3aGVuOiIsIG5vdCAia2lsbGVkIiB3aGVuLgoKVGhlIGxp dGVyYXR1cmUgbWFrZXMgYSBkaXN0aW5jdGlvbiBiZXR3ZWVuICJraWxsZWQiIGFuZCAid291bmRl ZCIuIEluIApvdXIgY29udGV4dCwgIktpbGxlZCIgaXMgd2hlbiBhIHRyYW5zYWN0aW9uIGFjdHVh bGx5IHJlY2VpdmVzIGFuIAotRURFQURMSyBhbmQgbmVlZHMgdG8gYmFjayBvZmYuICJXb3VuZGVk IiBpcyB3aGVuIHNvbWVvbmUgKHR5cGljYWxseSAKYW5vdGhlciB0cmFuc2FjdGlvbikgcmVxdWVz dHMgYSB0cmFuc2FjdGlvbiB0byBraWxsIGl0c2VsZi4gQSB3b3VuZCB3aWxsIApvZnRlbiwgYnV0 IG5vdCBhbHdheXMsIGxlYWQgdG8gYSBraWxsLiBJZiB0aGUgd291bmRlZCB0cmFuc2FjdGlvbiBo YXMgCmZpbmlzaGVkIGl0cyBsb2NraW5nIHNlcXVlbmNlLCBvciBoYXMgdGhlIG9wcG9ydHVuaXR5 IHRvIGdyYWIgCnVuY29udGVuZGVkIHd3IG11dGV4ZXMgb3Igc3RlYWwgY29udGVuZGVkIChub24t aGFuZG9mZikgd3cgbXV0ZXhlcyB0byAKZmluaXNoIGl0cyB0cmFuc2FjdGlvbiBpdCB3aWxsIGRv IHNvIGFuZCBuZXZlciBraWxsIGl0c2VsZi4KCgoKPgo+IEluIHNjaGVkdWxpbmcgc3BlYWsgcHJl ZW1wdGlvbiBpcyB3aGVuIHdlIHBpY2sgYSBydW5uYWJsZSAoYnV0ICFydW5uaW5nKQo+IHRhc2sg dG8gcnVuIGluc3RlYWQgb2YgdGhlIGN1cnJlbnQgcnVubmluZyB0YXNrLiAgSW4gdGhpcyBjYXNl IGhvd2V2ZXIsCj4gb3VyIFQyIGlzIGJsb2NrZWQgb24gYSBsb2NrIGFjcXVpc2l0aW9uIChvbmUg b3duZWQgYnkgb3VyIFQxKSBhbmQgVDEgaXMKPiB0aGUgb25seSBydW5uYWJsZSB0YXNrLiBPbmx5 IHdoZW4gVDEncyBwcm9ncmVzcyBpcyBpbmhpYml0ZWQgYnkgVDIgKFQxCj4gd2FudHMgYSBsb2Nr IGhlbGQgYnkgVDIpIGRvIHdlIHdvdW5kL3dha2UgVDIuCgpJbmRlZWQuIFRoZSBwcmVlbXB0aW9u IHNwb2tlbiBhYm91dCBpbiB0aGUgV291bmQtV2FpdCBsaXR0ZXJhdHVyZSBtZWFucyAKdGhhdCBh IHRyYW5zYWN0aW9uIHByZWVtcHRzIGFub3RoZXIgdHJhbnNhY3Rpb24gd2hlbiBpdCB3b3VuZHMg aXQuIEluIApkaXN0cmlidXRlZCBjb21wdXRpbmcgbXkgdW5kZXJzdGFuZGluZyBpcyB0aGF0IHRo ZSBwcmVlbXB0ZWQgdHJhbnNhY3Rpb24gCmlzIGFib3J0ZWQgaW5zdGFudGx5IGFuZCByZXN0YXJ0 ZWQgYWZ0ZXIgYSByYW5kb20gZGVsYXkuIE9mIGNvdXJzZSwgd2UgCmhhdmUgbm8gbWVhbnMgb2Yg bWFwcGluZyB3b3VuZGluZyB0byBwcm9jZXNzIHByZWVtcHRpb24gaW4gdGhlIGxpbnV4IAprZXJu ZWwsIHNvIHRoYXQncyB3aHkgSSByZWZlcnJlZCB0byBpdCBhcyAibGF6eSBwcmVlbXB0aW9uIi4g SW4gcHJvY2VzcyAKYW5hbG9neSAid291bmRlZCIgd291bmQgcm91Z2hseSBjb3JyZXNwb25kIHRv IChuZWVkX3Jlc2NoZWQoKSA9PSB0cnVlKSwgCmFuZCByZXR1cm5pbmcgLUVERUFETEsgd291bGQg Y29ycmVzcG9uZCB0byB2b2x1bnRhcnkgcHJlZW1wdGlvbi4KCgoKPgo+IEluIGFueSBjYXNlLCBJ IGhhZCBhIGxpdHRsZSBsb29rIGF0IHRoZSBjdXJyZW50IHd3X211dGV4IGNvZGUgYW5kIGVuZGVk Cj4gdXAgd2l0aCB0aGUgYmVsb3cgcGF0Y2ggdGhhdCBob3BlZnVsbHkgY2xhcmlmaWVzIHRoaW5n cyBhIGxpdHRsZS4KPgo+IC0tLQo+IGRpZmYgLS1naXQgYS9rZXJuZWwvbG9ja2luZy9tdXRleC5j IGIva2VybmVsL2xvY2tpbmcvbXV0ZXguYwo+IGluZGV4IGY0NGY2NThhZTYyOS4uYTIwYzA0NjE5 YjJhIDEwMDY0NAo+IC0tLSBhL2tlcm5lbC9sb2NraW5nL211dGV4LmMKPiArKysgYi9rZXJuZWwv bG9ja2luZy9tdXRleC5jCj4gQEAgLTI0NCw2ICsyNDQsMTAgQEAgdm9pZCBfX3NjaGVkIG11dGV4 X2xvY2soc3RydWN0IG11dGV4ICpsb2NrKQo+ICAgRVhQT1JUX1NZTUJPTChtdXRleF9sb2NrKTsK PiAgICNlbmRpZgo+ICAgCj4gKy8qCj4gKyAqIEFzc29jaWF0ZSB0aGUgd3dfbXV0ZXggQHd3IHdp dGggdGhlIGNvbnRleHQgQHd3X2N0eCB1bmRlciB3aGljaCB3ZSBhY3F1aXJlZAo+ICsgKiBpdC4K PiArICovCgpJTU8gdXNlIG9mICJhY3F1aXJlX2NvbnRleHQiIG9yICJjb250ZXh0IiBpcyBhIGxp dHRsZSB1bmZvcnR1bmF0ZSB3aGVuIAp0aGUgbGl0ZXJhdHVyZSB1c2VzICJ0cmFuc2FjdGlvbiIs CmJ1dCBvdGhlcndpc2UgZmluZS4KCgo+ICAgc3RhdGljIF9fYWx3YXlzX2lubGluZSB2b2lkCj4g ICB3d19tdXRleF9sb2NrX2FjcXVpcmVkKHN0cnVjdCB3d19tdXRleCAqd3csIHN0cnVjdCB3d19h Y3F1aXJlX2N0eCAqd3dfY3R4KQo+ICAgewo+IEBAIC0yODIsMjYgKzI4NiwzNiBAQCB3d19tdXRl eF9sb2NrX2FjcXVpcmVkKHN0cnVjdCB3d19tdXRleCAqd3csIHN0cnVjdCB3d19hY3F1aXJlX2N0 eCAqd3dfY3R4KQo+ICAgCURFQlVHX0xPQ0tTX1dBUk5fT04od3dfY3R4LT53d19jbGFzcyAhPSB3 dy0+d3dfY2xhc3MpOwo+ICAgI2VuZGlmCj4gICAJd3dfY3R4LT5hY3F1aXJlZCsrOwo+ICsJbG9j ay0+Y3R4ID0gY3R4Owo+ICAgfQo+ICAgCj4gKy8qCj4gKyAqIERldGVybWluZSBpZiBjb250ZXh0 IEBhIGlzICdhZnRlcicgY29udGV4dCBAYi4gSU9XLCBAYSBzaG91bGQgYmUgd291bmRlZCBpbgo+ ICsgKiBmYXZvdXIgb2YgQGIuCj4gKyAqLwoKU28gIndvdW5kZWQiIHNob3VsZCBuZXZlciByZWFs bHkgYmUgdXNlZCB3aXRoIFdhaXQtRGllCiJEZXRlcm1pbmUgd2hldGhlciBjb250ZXh0IEBhIHJl cHJlc2VudHMgYSB5b3VuZ2VyIHRyYW5zYWN0aW9uIHRoYW4gCmNvbnRleHQgQGIiPwoKPiAgIHN0 YXRpYyBpbmxpbmUgYm9vbCBfX3NjaGVkCj4gICBfX3d3X2N0eF9zdGFtcF9hZnRlcihzdHJ1Y3Qg d3dfYWNxdWlyZV9jdHggKmEsIHN0cnVjdCB3d19hY3F1aXJlX2N0eCAqYikKPiAgIHsKPiAtCXJl dHVybiBhLT5zdGFtcCAtIGItPnN0YW1wIDw9IExPTkdfTUFYICYmCj4gLQkgICAgICAgKGEtPnN0 YW1wICE9IGItPnN0YW1wIHx8IGEgPiBiKTsKPiArCj4gKwlyZXR1cm4gKHNpZ25lZCBsb25nKShh LT5zdGFtcCAtIGItPnN0YW1wKSA+IDA7Cj4gICB9Cj4gICAKPiAgIC8qCj4gLSAqIFdha2UgdXAg YW55IHdhaXRlcnMgdGhhdCBtYXkgaGF2ZSB0byBiYWNrIG9mZiB3aGVuIHRoZSBsb2NrIGlzIGhl bGQgYnkgdGhlCj4gLSAqIGdpdmVuIGNvbnRleHQuCj4gKyAqIFdlIGp1c3QgYWNxdWlyZWQgQGxv Y2sgdW5kZXIgQHd3X2N0eCwgaWYgdGhlcmUgYXJlIGxhdGVyIGNvbnRleHRzIHdhaXRpbmcKPiAr ICogYmVoaW5kIHVzIG9uIHRoZSB3YWl0LWxpc3QsIHdha2UgdGhlbSB1cCBzbyB0aGV5IGNhbiB3 b3VuZCB0aGVtc2VsdmVzLgoKQWN0dWFsbHkgZm9yIFdhaXQtRGllLCBCYWNrIG9mZiBvciAiRGll IiBpcyB0aGUgY29ycmVjdCB0ZXJtaW5vbG9neS4KCj4gICAgKgo+IC0gKiBEdWUgdG8gdGhlIGlu dmFyaWFudHMgb24gdGhlIHdhaXQgbGlzdCwgdGhpcyBjYW4gb25seSBhZmZlY3QgdGhlIGZpcnN0 Cj4gLSAqIHdhaXRlciB3aXRoIGEgY29udGV4dC4KPiArICogU2VlIF9fd3dfbXV0ZXhfYWRkX3dh aXRlcigpIGZvciB0aGUgbGlzdC1vcmRlciBjb25zdHJ1Y3Rpb247IGJhc2ljYWxseSB0aGUKPiAr ICogbGlzdCBpcyBvcmRlcmVkIGJ5IHN0YW1wIHNtYWxsZXN0IChvbGRlc3QpIGZpcnN0LCBzbyBp ZiB0aGVyZSBpcyBhIGxhdGVyCj4gKyAqICh5b3VuZ2VyKSBzdGFtcCBvbiB0aGUgbGlzdCBiZWhp bmQgdXMsIHdha2UgaXQgc28gaXQgY2FuIHdvdW5kIGl0c2VsZi4KPiArICoKPiArICogQmVjYXVz ZSBfX3d3X211dGV4X2FkZF93YWl0ZXIoKSBhbmQgX193d19tdXRleF9jaGVja19zdGFtcCgpIHdh a2UgYW55Cj4gKyAqIGJ1dCB0aGUgZWFybGllc3QgY29udGV4dCwgdGhpcyBjYW4gb25seSBhZmZl Y3QgdGhlIGZpcnN0IHdhaXRlciAod2l0aCBhCj4gKyAqIGNvbnRleHQpLgoKVGhlIHdhaXQgbGlz dCBpbnZhcmlhbnRzIGFyZSBzdGF0ZWQgaW4gCkRvY3VtZW50YXRpb24vbG9ja2luZy93dy1tdXRl eC1kZXNpZ24udHh0LgpQZXJoYXBzIHdlIGNvdWxkIGNvcHkgdGhvc2UgaW50byB0aGUgY29kZSB0 byBtYWtlIHRoZSBjb21tZW50IG1vcmUgCnVuZGVyc3RhbmRhYmxlOgoiwqAgV2UgbWFpbnRhaW4g dGhlIGZvbGxvd2luZyBpbnZhcmlhbnRzIGZvciB0aGUgd2FpdCBsaXN0OgogwqAgKDEpIFdhaXRl cnMgd2l0aCBhbiBhY3F1aXJlIGNvbnRleHQgYXJlIHNvcnRlZCBieSBzdGFtcCBvcmRlcjsgd2Fp dGVycwogwqDCoMKgwqDCoCB3aXRob3V0IGFuIGFjcXVpcmUgY29udGV4dCBhcmUgaW50ZXJzcGVy c2VkIGluIEZJRk8gb3JkZXIuCiDCoCAoMikgRm9yIFdhaXQtRGllLCBhbW9uZyB3YWl0ZXJzIHdp dGggY29udGV4dHMsIG9ubHkgdGhlIGZpcnN0IG9uZSBjYW4gCmhhdmUKIMKgwqDCoMKgwqAgb3Ro ZXIgbG9ja3MgYWNxdWlyZWQgYWxyZWFkeSAoY3R4LT5hY3F1aXJlZCA+IDApLiBOb3RlIHRoYXQg dGhpcyAKd2FpdGVyCiDCoMKgwqDCoMKgIG1heSBjb21lIGFmdGVyIG90aGVyIHdhaXRlcnMgd2l0 aG91dCBjb250ZXh0cyBpbiB0aGUgbGlzdC4iCgo+ICAgICoKPiAgICAqIFRoZSBjdXJyZW50IHRh c2sgbXVzdCBub3QgYmUgb24gdGhlIHdhaXQgbGlzdC4KPiAgICAqLwo+ICAgc3RhdGljIHZvaWQg X19zY2hlZAo+IC1fX3d3X211dGV4X3dha2V1cF9mb3JfYmFja29mZihzdHJ1Y3QgbXV0ZXggKmxv Y2ssIHN0cnVjdCB3d19hY3F1aXJlX2N0eCAqd3dfY3R4KQo+ICtfX3d3X211dGV4X3dha2V1cF9m b3Jfd291bmQoc3RydWN0IG11dGV4ICpsb2NrLCBzdHJ1Y3Qgd3dfYWNxdWlyZV9jdHggKnd3X2N0 eCkKCkFnYWluLCAid291bmQiIGlzIHVuc3VpdGFibGUgZm9yIFdhaXQtRGllLiArIG51bWVyb3Vz IGFkZGl0aW9uYWwgcGxhY2VzLgoKVGhhbmtzLApUaG9tYXMKCgoKCl9fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJp LWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9y Zy9tYWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZlbAo=