From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46717) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fyJFA-0000c8-2N for qemu-devel@nongnu.org; Fri, 07 Sep 2018 12:04:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fyJF5-0005bm-Rj for qemu-devel@nongnu.org; Fri, 07 Sep 2018 12:04:23 -0400 Received: from smtp.eu.citrix.com ([185.25.65.24]:42418) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fyJF5-0005Iy-Av for qemu-devel@nongnu.org; Fri, 07 Sep 2018 12:04:19 -0400 From: Paul Durrant Date: Fri, 7 Sep 2018 16:03:38 +0000 Message-ID: References: <153631568068.32214.13361287430751567885.stgit@dhcp-3-135.uk.xensource.com> <153631568573.32214.15572432320859976670.stgit@dhcp-3-135.uk.xensource.com> In-Reply-To: <153631568573.32214.15572432320859976670.stgit@dhcp-3-135.uk.xensource.com> Content-Language: en-US Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 2/3] Improve xen_disk response latency List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Tim Smith , "qemu-devel@nongnu.org" PiAtLS0tLU9yaWdpbmFsIE1lc3NhZ2UtLS0tLQ0KPiBGcm9tOiBRZW11LWRldmVsIFttYWlsdG86 cWVtdS1kZXZlbC0NCj4gYm91bmNlcytwYXVsLmR1cnJhbnQ9Y2l0cml4LmNvbUBub25nbnUub3Jn XSBPbiBCZWhhbGYgT2YgVGltIFNtaXRoDQo+IFNlbnQ6IDA3IFNlcHRlbWJlciAyMDE4IDExOjIx DQo+IFRvOiBxZW11LWRldmVsQG5vbmdudS5vcmcNCj4gU3ViamVjdDogW1FlbXUtZGV2ZWxdIFtQ QVRDSCAyLzNdIEltcHJvdmUgeGVuX2Rpc2sgcmVzcG9uc2UgbGF0ZW5jeQ0KPiANCj4gSWYgdGhl IEkvTyByaW5nIGlzIGZ1bGwsIHRoZSBndWVzdCBjYW5ub3Qgc2VuZCBhbnkgbW9yZSByZXF1ZXN0 cw0KPiB1bnRpbCBzb21lIHJlc3BvbnNlcyBhcmUgc2VudC4gT25seSBzZW5kaW5nIGFsbCBhdmFp bGFibGUgcmVzcG9uc2VzDQo+IGp1c3QgYmVmb3JlIGNoZWNraW5nIGZvciBuZXcgd29yayBkb2Vz IG5vdCBsZWF2ZSBtdWNoIHRpbWUgZm9yIHRoZQ0KPiBndWVzdCB0byBzdXBwbHkgbmV3IHdvcmss IHNvIHRoaXMgd2lsbCBjYXVzZSBzdGFsbHMgaWYgdGhlIHJpbmcgZ2V0cw0KPiBmdWxsLiBBbHNv LCBub3QgY29tcGxldGluZyByZWFkcyBhcyBzb29uIGFzIHBvc3NpYmxlIGFkZHMgbGF0ZW5jeQ0K PiB0byB0aGUgZ3Vlc3QuDQo+IA0KPiBUbyBhbGxldmlhdGUgdGhhdCwgY29tcGxldGUgSU8gcmVx dWVzdHMgYXMgc29vbiBhcyB0aGV5IGNvbWUgYmFjay4NCj4gYmxrX3NlbmRfcmVzcG9uc2UoKSBh bHJlYWR5IHJldHVybnMgYSB2YWx1ZSBpbmRpY2F0aW5nIHdoZXRoZXINCj4gYSBub3RpZnkgc2hv dWxkIGJlIHNlbnQsIHdoaWNoIGlzIGFsbCB0aGUgYmF0Y2hpbmcgd2UgbmVlZC4NCj4gDQo+IFNp Z25lZC1vZmYtYnk6IFRpbSBTbWl0aCA8dGltLnNtaXRoQGNpdHJpeC5jb20+DQoNClJldmlld2Vk LWJ5OiBQYXVsIER1cnJhbnQgPHBhdWwuZHVycmFudEBjaXRyaXguY29tPg0KDQo+IC0tLQ0KPiAg aHcvYmxvY2sveGVuX2Rpc2suYyB8ICAgNDMgKysrKysrKysrKysrLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLQ0KPiAgMSBmaWxlIGNoYW5nZWQsIDEyIGluc2VydGlvbnMoKyksIDMxIGRl bGV0aW9ucygtKQ0KPiANCj4gZGlmZiAtLWdpdCBhL2h3L2Jsb2NrL3hlbl9kaXNrLmMgYi9ody9i bG9jay94ZW5fZGlzay5jDQo+IGluZGV4IDZjYjQwZDY2ZmEuLmMxMWNkMjFkMzcgMTAwNjQ0DQo+ IC0tLSBhL2h3L2Jsb2NrL3hlbl9kaXNrLmMNCj4gKysrIGIvaHcvYmxvY2sveGVuX2Rpc2suYw0K PiBAQCAtODMsMTEgKzgzLDkgQEAgc3RydWN0IFhlbkJsa0RldiB7DQo+IA0KPiAgICAgIC8qIHJl cXVlc3QgbGlzdHMgKi8NCj4gICAgICBRTElTVF9IRUFEKGluZmxpZ2h0X2hlYWQsIGlvcmVxKSBp bmZsaWdodDsNCj4gLSAgICBRTElTVF9IRUFEKGZpbmlzaGVkX2hlYWQsIGlvcmVxKSBmaW5pc2hl ZDsNCj4gICAgICBRTElTVF9IRUFEKGZyZWVsaXN0X2hlYWQsIGlvcmVxKSBmcmVlbGlzdDsNCj4g ICAgICBpbnQgICAgICAgICAgICAgICAgIHJlcXVlc3RzX3RvdGFsOw0KPiAgICAgIGludCAgICAg ICAgICAgICAgICAgcmVxdWVzdHNfaW5mbGlnaHQ7DQo+IC0gICAgaW50ICAgICAgICAgICAgICAg ICByZXF1ZXN0c19maW5pc2hlZDsNCj4gICAgICB1bnNpZ25lZCBpbnQgICAgICAgIG1heF9yZXF1 ZXN0czsNCj4gDQo+ICAgICAgZ2Jvb2xlYW4gICAgICAgICAgICBmZWF0dXJlX2Rpc2NhcmQ7DQo+ IEBAIC0xMDQsNiArMTAyLDkgQEAgc3RydWN0IFhlbkJsa0RldiB7DQo+ICAvKiBUaHJlc2hvbGQg b2YgaW4tZmxpZ2h0IHJlcXVlc3RzIGFib3ZlIHdoaWNoIHdlIHdpbGwgc3RhcnQgdXNpbmcNCj4g ICAqIGJsa19pb19wbHVnKCkvYmxrX2lvX3VucGx1ZygpIHRvIGJhdGNoIHJlcXVlc3RzICovDQo+ ICAjZGVmaW5lIElPX1BMVUdfVEhSRVNIT0xEIDENCj4gKw0KPiArc3RhdGljIGludCBibGtfc2Vu ZF9yZXNwb25zZShzdHJ1Y3QgaW9yZXEgKmlvcmVxKTsNCj4gKw0KPiAgLyogLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLSAqLw0KPiAN Cj4gIHN0YXRpYyB2b2lkIGlvcmVxX3Jlc2V0KHN0cnVjdCBpb3JlcSAqaW9yZXEpDQo+IEBAIC0x NTUsMTIgKzE1NiwxMCBAQCBzdGF0aWMgdm9pZCBpb3JlcV9maW5pc2goc3RydWN0IGlvcmVxICpp b3JlcSkNCj4gICAgICBzdHJ1Y3QgWGVuQmxrRGV2ICpibGtkZXYgPSBpb3JlcS0+YmxrZGV2Ow0K PiANCj4gICAgICBRTElTVF9SRU1PVkUoaW9yZXEsIGxpc3QpOw0KPiAtICAgIFFMSVNUX0lOU0VS VF9IRUFEKCZibGtkZXYtPmZpbmlzaGVkLCBpb3JlcSwgbGlzdCk7DQo+ICAgICAgYmxrZGV2LT5y ZXF1ZXN0c19pbmZsaWdodC0tOw0KPiAtICAgIGJsa2Rldi0+cmVxdWVzdHNfZmluaXNoZWQrKzsN Cj4gIH0NCj4gDQo+IC1zdGF0aWMgdm9pZCBpb3JlcV9yZWxlYXNlKHN0cnVjdCBpb3JlcSAqaW9y ZXEsIGJvb2wgZmluaXNoKQ0KPiArc3RhdGljIHZvaWQgaW9yZXFfcmVsZWFzZShzdHJ1Y3QgaW9y ZXEgKmlvcmVxKQ0KPiAgew0KPiAgICAgIHN0cnVjdCBYZW5CbGtEZXYgKmJsa2RldiA9IGlvcmVx LT5ibGtkZXY7DQo+IA0KPiBAQCAtMTY4LDExICsxNjcsNyBAQCBzdGF0aWMgdm9pZCBpb3JlcV9y ZWxlYXNlKHN0cnVjdCBpb3JlcSAqaW9yZXEsIGJvb2wNCj4gZmluaXNoKQ0KPiAgICAgIGlvcmVx X3Jlc2V0KGlvcmVxKTsNCj4gICAgICBpb3JlcS0+YmxrZGV2ID0gYmxrZGV2Ow0KPiAgICAgIFFM SVNUX0lOU0VSVF9IRUFEKCZibGtkZXYtPmZyZWVsaXN0LCBpb3JlcSwgbGlzdCk7DQo+IC0gICAg aWYgKGZpbmlzaCkgew0KPiAtICAgICAgICBibGtkZXYtPnJlcXVlc3RzX2ZpbmlzaGVkLS07DQo+ IC0gICAgfSBlbHNlIHsNCj4gLSAgICAgICAgYmxrZGV2LT5yZXF1ZXN0c19pbmZsaWdodC0tOw0K PiAtICAgIH0NCj4gKyAgICBibGtkZXYtPnJlcXVlc3RzX2luZmxpZ2h0LS07DQo+ICB9DQo+IA0K PiAgLyoNCj4gQEAgLTM1MSw2ICszNDYsMTAgQEAgc3RhdGljIHZvaWQgcWVtdV9haW9fY29tcGxl dGUodm9pZCAqb3BhcXVlLCBpbnQNCj4gcmV0KQ0KPiAgICAgIGRlZmF1bHQ6DQo+ICAgICAgICAg IGJyZWFrOw0KPiAgICAgIH0NCj4gKyAgICBpZiAoYmxrX3NlbmRfcmVzcG9uc2UoaW9yZXEpKSB7 DQo+ICsgICAgICAgIHhlbl9wdl9zZW5kX25vdGlmeSgmYmxrZGV2LT54ZW5kZXYpOw0KPiArICAg IH0NCj4gKyAgICBpb3JlcV9yZWxlYXNlKGlvcmVxKTsNCj4gICAgICBxZW11X2JoX3NjaGVkdWxl KGJsa2Rldi0+YmgpOw0KPiANCj4gIGRvbmU6DQo+IEBAIC00NTUsNyArNDU0LDcgQEAgZXJyOg0K PiAgICAgIHJldHVybiAtMTsNCj4gIH0NCj4gDQo+IC1zdGF0aWMgaW50IGJsa19zZW5kX3Jlc3Bv bnNlX29uZShzdHJ1Y3QgaW9yZXEgKmlvcmVxKQ0KPiArc3RhdGljIGludCBibGtfc2VuZF9yZXNw b25zZShzdHJ1Y3QgaW9yZXEgKmlvcmVxKQ0KPiAgew0KPiAgICAgIHN0cnVjdCBYZW5CbGtEZXYg ICpibGtkZXYgPSBpb3JlcS0+YmxrZGV2Ow0KPiAgICAgIGludCAgICAgICAgICAgICAgIHNlbmRf bm90aWZ5ICAgPSAwOw0KPiBAQCAtNTA0LDIyICs1MDMsNiBAQCBzdGF0aWMgaW50IGJsa19zZW5k X3Jlc3BvbnNlX29uZShzdHJ1Y3QgaW9yZXENCj4gKmlvcmVxKQ0KPiAgICAgIHJldHVybiBzZW5k X25vdGlmeTsNCj4gIH0NCj4gDQo+IC0vKiB3YWxrIGZpbmlzaGVkIGxpc3QsIHNlbmQgb3V0c3Rh bmRpbmcgcmVzcG9uc2VzLCBmcmVlIHJlcXVlc3RzICovDQo+IC1zdGF0aWMgdm9pZCBibGtfc2Vu ZF9yZXNwb25zZV9hbGwoc3RydWN0IFhlbkJsa0RldiAqYmxrZGV2KQ0KPiAtew0KPiAtICAgIHN0 cnVjdCBpb3JlcSAqaW9yZXE7DQo+IC0gICAgaW50IHNlbmRfbm90aWZ5ID0gMDsNCj4gLQ0KPiAt ICAgIHdoaWxlICghUUxJU1RfRU1QVFkoJmJsa2Rldi0+ZmluaXNoZWQpKSB7DQo+IC0gICAgICAg IGlvcmVxID0gUUxJU1RfRklSU1QoJmJsa2Rldi0+ZmluaXNoZWQpOw0KPiAtICAgICAgICBzZW5k X25vdGlmeSArPSBibGtfc2VuZF9yZXNwb25zZV9vbmUoaW9yZXEpOw0KPiAtICAgICAgICBpb3Jl cV9yZWxlYXNlKGlvcmVxLCB0cnVlKTsNCj4gLSAgICB9DQo+IC0gICAgaWYgKHNlbmRfbm90aWZ5 KSB7DQo+IC0gICAgICAgIHhlbl9wdl9zZW5kX25vdGlmeSgmYmxrZGV2LT54ZW5kZXYpOw0KPiAt ICAgIH0NCj4gLX0NCj4gLQ0KPiAgc3RhdGljIGludCBibGtfZ2V0X3JlcXVlc3Qoc3RydWN0IFhl bkJsa0RldiAqYmxrZGV2LCBzdHJ1Y3QgaW9yZXEgKmlvcmVxLA0KPiBSSU5HX0lEWCByYykNCj4g IHsNCj4gICAgICBzd2l0Y2ggKGJsa2Rldi0+cHJvdG9jb2wpIHsNCj4gQEAgLTU1NCw3ICs1Mzcs NiBAQCBzdGF0aWMgdm9pZCBibGtfaGFuZGxlX3JlcXVlc3RzKHN0cnVjdCBYZW5CbGtEZXYNCj4g KmJsa2RldikNCj4gICAgICBycCA9IGJsa2Rldi0+cmluZ3MuY29tbW9uLnNyaW5nLT5yZXFfcHJv ZDsNCj4gICAgICB4ZW5fcm1iKCk7IC8qIEVuc3VyZSB3ZSBzZWUgcXVldWVkIHJlcXVlc3RzIHVw IHRvICdycCcuICovDQo+IA0KPiAtICAgIGJsa19zZW5kX3Jlc3BvbnNlX2FsbChibGtkZXYpOw0K PiAgICAgIC8qIElmIHRoZXJlIHdhcyBtb3JlIHRoYW4gSU9fUExVR19USFJFU0hPTEQgaW9yZXFz IGluIGZsaWdodA0KPiAgICAgICAqIHdoZW4gd2UgZ290IGhlcmUsIHRoaXMgaXMgYW4gaW5kaWNh dGlvbiB0aGF0IHRoZXJlIHRoZSBib3R0bGVuZWNrDQo+ICAgICAgICogaXMgYmVsb3cgdXMsIHNv IGl0J3Mgd29ydGggYmVnaW5uaW5nIHRvIGJhdGNoIHVwIEkvTyByZXF1ZXN0cw0KPiBAQCAtNTk3 LDEwICs1NzksMTAgQEAgc3RhdGljIHZvaWQgYmxrX2hhbmRsZV9yZXF1ZXN0cyhzdHJ1Y3QgWGVu QmxrRGV2DQo+ICpibGtkZXYpDQo+ICAgICAgICAgICAgICAgICAgYnJlYWs7DQo+ICAgICAgICAg ICAgICB9Ow0KPiANCj4gLSAgICAgICAgICAgIGlmIChibGtfc2VuZF9yZXNwb25zZV9vbmUoaW9y ZXEpKSB7DQo+ICsgICAgICAgICAgICBpZiAoYmxrX3NlbmRfcmVzcG9uc2UoaW9yZXEpKSB7DQo+ ICAgICAgICAgICAgICAgICAgeGVuX3B2X3NlbmRfbm90aWZ5KCZibGtkZXYtPnhlbmRldik7DQo+ ICAgICAgICAgICAgICB9DQo+IC0gICAgICAgICAgICBpb3JlcV9yZWxlYXNlKGlvcmVxLCBmYWxz ZSk7DQo+ICsgICAgICAgICAgICBpb3JlcV9yZWxlYXNlKGlvcmVxKTsNCj4gICAgICAgICAgICAg IGNvbnRpbnVlOw0KPiAgICAgICAgICB9DQo+IA0KPiBAQCAtNjQ1LDcgKzYyNyw2IEBAIHN0YXRp YyB2b2lkIGJsa19hbGxvYyhzdHJ1Y3QgWGVuRGV2aWNlICp4ZW5kZXYpDQo+ICAgICAgdHJhY2Vf eGVuX2Rpc2tfYWxsb2MoeGVuZGV2LT5uYW1lKTsNCj4gDQo+ICAgICAgUUxJU1RfSU5JVCgmYmxr ZGV2LT5pbmZsaWdodCk7DQo+IC0gICAgUUxJU1RfSU5JVCgmYmxrZGV2LT5maW5pc2hlZCk7DQo+ ICAgICAgUUxJU1RfSU5JVCgmYmxrZGV2LT5mcmVlbGlzdCk7DQo+IA0KPiAgICAgIGJsa2Rldi0+ aW90aHJlYWQgPSBpb3RocmVhZF9jcmVhdGUoeGVuZGV2LT5uYW1lLCAmZXJyKTsNCj4gDQoNCg==