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Mon, 03 Feb 2020 09:59:18 -0500 X-MC-Unique: AQ28BhP9OMiZy0cL1mIydQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 81DD71800D41; Mon, 3 Feb 2020 14:59:15 +0000 (UTC) Received: from llong.remote.csb (dhcp-17-59.bos.redhat.com [10.18.17.59]) by smtp.corp.redhat.com (Postfix) with ESMTP id E429219C58; Mon, 3 Feb 2020 14:59:12 +0000 (UTC) Subject: Re: [PATCH v8 4/5] locking/qspinlock: Introduce starvation avoidance into CNA To: Peter Zijlstra , Alex Kogan References: <3862F8A1-FF9B-40AD-A88E-2C0BA7AF6F58@oracle.com> <20200124075235.GX14914@hirez.programming.kicks-ass.net> <2c6741c5-d89d-4b2c-cebe-a7c7f6eed884@redhat.com> <48ce49e5-98a7-23cd-09f4-8290a65abbb5@redhat.com> <8D3AFB47-B595-418C-9568-08780DDC58FF@oracle.com> <714892cd-d96f-4d41-ae8b-d7b7642a6e3c@redhat.com> <1669BFDE-A1A5-4ED8-B586-035460BBF68A@oracle.com> <20200125111931.GW11457@worktop.programming.kicks-ass.net> <20200203134540.GA14879@hirez.programming.kicks-ass.net> From: Waiman Long Organization: Red Hat Message-ID: <6d11b22b-2fb5-7dea-f88b-b32f1576a5e0@redhat.com> Date: Mon, 3 Feb 2020 09:59:12 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20200203134540.GA14879@hirez.programming.kicks-ass.net> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200203_065926_093795_C9FF418F X-CRM114-Status: GOOD ( 16.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Hanjun Guo , Arnd Bergmann , dave.dice@oracle.com, Jan Glauber , x86@kernel.org, Will Deacon , linux@armlinux.org.uk, linux-kernel@vger.kernel.org, Ingo Molnar , Borislav Petkov , hpa@zytor.com, Steven Sistare , Thomas Gleixner , Daniel Jordan , linux-arm-kernel Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gMi8zLzIwIDg6NDUgQU0sIFBldGVyIFppamxzdHJhIHdyb3RlOgo+IE9uIFRodSwgSmFuIDMw LCAyMDIwIGF0IDA1OjA1OjI4UE0gLTA1MDAsIEFsZXggS29nYW4gd3JvdGU6Cj4+PiBPbiBKYW4g MjUsIDIwMjAsIGF0IDY6MTkgQU0sIFBldGVyIFppamxzdHJhIDxwZXRlcnpAaW5mcmFkZWFkLm9y Zz4gd3JvdGU6Cj4+Pgo+Pj4gT24gRnJpLCBKYW4gMjQsIDIwMjAgYXQgMDE6MTk6MDVQTSAtMDUw MCwgQWxleCBLb2dhbiB3cm90ZToKPj4+Cj4+Pj4gSXMgdGhlcmUgYSBsaWdodHdlaWdodCB3YXkg dG8gaWRlbnRpZnkgc3VjaCBhIOKAnHByaW9yaXRpemVk4oCdIHRocmVhZD8KPj4+IE5vOyBwZW9w bGUgbWlnaHQgZm9yIGluc3RhbmNlIGNhcmUgYWJvdXQgdGFpbCBsYXRlbmNpZXMgYmV0d2VlbiB0 aGVpcgo+Pj4gaWRlbnRpY2FsbHkgc3BlYydlZCB3b3JrZXIgdGFza3MuCj4+IEkgd291bGQgYXJn dWUgdGhhdCB0aG9zZSB1c2VycyBuZWVkIHRvIHR1bmUvcmVkdWNlIHRoZSBpbnRyYS1ub2RlIGhh bmRvZmYKPj4gdGhyZXNob2xkIGZvciB0aGVpciBuZWVkcy4gT3IgZGlzYWJsZSBDTkEgYWx0b2dl dGhlci4KPiBJIHJlYWxseSBkb24ndCBsaWtlIGJvb3QgdGltZSBhcmd1bWVudHMgKG9yIHR1bmFi bGVzIGluIGdlbmVyaWMpIGZvciBhCj4gbWFjaGluZSB0byB3b3JrIGFzIGl0IHNob3VsZC4KPgo+ IFRoZSBkZWZhdWx0IHJlYWxseSBzaG91bGQgJ2p1c3Qgd29yaycuClRoYXQgd2lsbCBiZSB0aGUg aWRlYWwgY2FzZS4gSW4gcmVhbGl0eSwgaXQgdXN1YWxseSB0YWtlcyBhIHdoaWxlIGZvcgp0aGUg Y29kZSB0byBtYXR1cmUgZW5vdWdoIHRvIGRvIHNvbWUga2luZCBvZiBzZWxmIHR1bmluZy4gSW4g dGhlIG1lYW4KdGltZSwgaGF2aW5nIHNvbWUgY29uZmlndXJhdGlvbiBvcHRpb25zIGF2YWlsYWJs ZSBhbGxvd3MgdXMgdG8gaGF2ZSBtb3JlCnRpbWUgdG8gZmlndXJlIHdoYXQgdGhlIGJlc3QgY29u ZmlndXJhdGlvbiBvcHRpb25zIHRvIGJlLgo+PiBJbiBnZW5lcmFsLCBQZXRlciwgc2VlbXMgbGlr ZSB5b3UgYXJlIG5vdCBvbiBib2FyZCB3aXRoIHRoZSB3YXkgTG9uZ21hbgo+PiBzdWdnZXN0ZWQg dG8gaGFuZGxlIHByaW9yaXRpemVkIHRocmVhZHMuIEFtIEkgcmlnaHQ/Cj4gUmlnaHQuCj4KPiBQ cmVzdW1hYmx5IHlvdSBoYXZlIGEgd29ya2xvYWQgd2hlcmUgQ05BIGlzIGFjdHVhbGx5IGEgd2lu PyBUaGF0IGlzLAo+IHdoYXQgaW5zcGlyZWQgeW91IHRvIGdvIGRvd24gdGhpcyByb2FkPyBXaGlj aCBhY3R1YWwga2VybmVsIGxvY2sgaXMgc28KPiBjb250ZW5kZWQgb24gTlVNQSBtYWNoaW5lcyB0 aGF0IHdlIG5lZWQgdG8gZG8gdGhpcz8KClRvZGF5LCBhIDItc29ja2V0IFJvbWUgc2VydmVyIGNh biBoYXZlIDEyOCBjb3JlcyBhbmQgMjU2IHRocmVhZHMuIElmIHdlCnNjYWxlIHVwIG1vcmUsIHdl IGNvdWxkIGVhc2lseSBoYXZlIG1vcmUgdGhhbiAxMDAwIHRocmVhZHMgaW4gYSBzeXN0ZW0uCldp dGggdGhhdCBtYW55IGxvZ2ljYWwgY3B1cyBhdmFpbGFibGUsIGl0IGlzIGVhc3kgdG8gZW52aXNp b24gc29tZSBoZWF2eQpzcGlubG9jayBjb250ZW50aW9uIGNhbiBoYXBwZW4gZmFpcmx5IHJlZ3Vs YXJseS4gVGhpcyBwYXRjaCBjYW4KYWxsZXZpYXRlIHRoZSBjb25nZXN0aW9uIGFuZCBpbXByb3Zl IHBlcmZvcm1hbmNlIHVuZGVyIHRoYXQKY2lyY3Vtc3RhbmNlLiBPZiBjb3Vyc2UsIHRoZSBzcGVj aWZpYyBsb2NrcyB0aGF0IGFyZSBjb250ZW5kZWQgd2lsbApkZXBlbmQgb24gdGhlIHdvcmtsb2Fk cy4KCkNoZWVycywKTG9uZ21hbgoKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4LWFybS1rZXJu ZWxAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFu L2xpc3RpbmZvL2xpbnV4LWFybS1rZXJuZWwK