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spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=U964neMZhxoxuuFBznxEHxWQ6+P2GQESGgaXXBJMY2s=; b=Zkib9vzqfKsR7N 774p+WJJ9IXH3F4OsR6O+r20U0oxzR3vXHxzBu+GY7QjY+9FCr+iy/IipOTpkwu9qrvMJ3TymCuhW DPN1K+FHHRqmJzNRdZMNSZQAL8L2K2X8son8BnyqjapBVrvQZ/ecmUvc6S+6QQhBj1eEw+rk7g5KU z26WtP7MwcelucHMrkhfuAmOEz5PL1O6aEjwwhjPgYSMNQjUBuKWVzqfKwK+Qtkp/YdTholDyW8Z9 YjEagWBpt62mM4CstSiYVHYXws73WALeKYKLr6l0VRjzii5nPU7/KM+nIcuNawuGMzoL0mDWFHpZN 3pEdCo+L6oIdQ6HZftyg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m0mRP-00C5Ch-J7; Tue, 06 Jul 2021 14:52:51 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m0mRM-00C5CI-Pr for linux-arm-kernel@lists.infradead.org; Tue, 06 Jul 2021 14:52:50 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 90D40613B2; Tue, 6 Jul 2021 14:52:48 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1m0mRK-00BkmS-Ha; Tue, 06 Jul 2021 15:52:46 +0100 Date: Tue, 06 Jul 2021 15:52:46 +0100 Message-ID: <87y2aj7av5.wl-maz@kernel.org> From: Marc Zyngier To: Alexandre Chartre Cc: will@kernel.org, catalin.marinas@arm.com, alexandru.elisei@arm.com, james.morse@arm.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, konrad.wilk@oracle.com Subject: Re: [PATCH] KVM: arm64: Disabling disabled PMU counters wastes a lot of time In-Reply-To: References: <20210628161925.401343-1-alexandre.chartre@oracle.com> <878s2tavks.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: alexandre.chartre@oracle.com, will@kernel.org, catalin.marinas@arm.com, alexandru.elisei@arm.com, james.morse@arm.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, konrad.wilk@oracle.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210706_075248_909187_5F68BC7F X-CRM114-Status: GOOD ( 20.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gVHVlLCAwNiBKdWwgMjAyMSAxNDo1MDozNSArMDEwMCwKQWxleGFuZHJlIENoYXJ0cmUgPGFs ZXhhbmRyZS5jaGFydHJlQG9yYWNsZS5jb20+IHdyb3RlOgo+IAo+IAo+IEhpIE1hcmMsCj4gCj4g T24gNi8yOS8yMSAzOjE2IFBNLCBBbGV4YW5kcmUgQ2hhcnRyZSB3cm90ZToKPiA+IE9uIDYvMjkv MjEgMTE6MDYgQU0sIE1hcmMgWnluZ2llciB3cm90ZQo+ID4gWy4uLl0KPiA+PiBTb8KgdGhlwqBz eXNyZWfCoGlzwqB0aGXCoG9ubHnCoHRoaW5nwqB3ZcKgc2hvdWxkwqBjb25zaWRlcizCoGFuZMKg ScKgdGhpbmvCoHdlCj4gPj4gc2hvdWxkwqBkcm9wwqB0aGXCoHVzZWxlc3PCoG1hc2tpbmcuwqBU aGVyZcKgaXPCoGF0wqBsZWFzdMKgYW5vdGhlcsKgaW5zdGFuY2XCoG9mCj4gPj4gdGhpc8KgaW7C oHRoZcKgUE1VwqBjb2RlwqAoa3ZtX3BtdV9vdmVyZmxvd19zdGF0dXMoKSkswqBhbmTCoGFwYXJ0 wqBmcm9tCj4gPj4ga3ZtX3BtdV92Y3B1X3Jlc2V0KCkswqBvbmx5wqB0aGXCoHN5c3JlZ8KgYWNj ZXNzb3JzwqBzaG91bGTCoGNhcmXCoGFib3V0wqB0aGUKPiA+PiBtYXNraW5nwqB0b8Kgc2FuaXRp c2XCoGFjY2Vzc2VzLgo+ID4+IAo+ID4+IFdoYXTCoGRvwqB5b3XCoHRoaW5rPwo+ID4+IAo+ID4g Cj4gPiBJwqB0aGlua8KgeW91wqBhcmXCoHJpZ2h0LsKgUE1DTlRFTlNFVF9FTDDCoGlzwqBhbHJl YWR5wqBtYXNrZWTCoHdpdGjCoGt2bV9wbXVfdmFsaWRfY291bnRlcl9tYXNrKCkKPiA+IHNvwqB0 aGVyZSdzwqBlZmZlY3RpdmVsecKgbm/CoG5lZWTCoHRvwqBtYXNrwqBpdMKgYWdhaW7CoHdoZW7C oHdlwqB1c2XCoGl0LsKgScKgd2lsbMKgc2VuZMKgYW7CoGFkZGl0aW9uYWwKPiA+IHBhdGNowqAo b27CoHRvcMKgb2bCoHRoaXPCoG9uZSnCoHRvwqByZW1vdmXCoHVzZWxlc3PCoG1hc2tpbmcuwqBC YXNpY2FsbHkswqBjaGFuZ2VzwqB3b3VsZMKgYmU6Cj4gCj4gSSBoYWQgYSBjbG9zZXIgbG9vayBh bmQgd2UgY2FuJ3QgcmVtb3ZlIHRoZSBtYXNrLiBUaGUgYWNjZXNzCj4gZnVuY3Rpb25zIChmb3Ig cG1jbnRlbiwgcG1pbnRlbiwgcG1vdnMpLCBjbGVhciBvciBzZXQgb25seSB0aGUKPiBzcGVjaWZp ZWQgdmFsaWQgY291bnRlciBiaXRzLiBUaGlzIG1lYW5zIHRoYXQgYml0cyBvdGhlciB0aGFuIHRo ZQo+IHZhbGlkIGNvdW50ZXIgYml0cyBuZXZlciBjaGFuZ2UgaW4gX192Y3B1X3N5c19yZWcoKSwg YW5kIHRob3NlIGJpdHMKPiBhcmUgbm90IG5lY2Vzc2FyaWx5IHplcm8gYmVjYXVzZSB0aGUgaW5p dGlhbCB2YWx1ZSBpcwo+IDB4MWRlN2VjN2VkYmFkYzBkZVVMTCAoc2V0IGJ5IHJlc2V0X3Vua25v d24oKSkuCgpUaGF0J3MgYSBidWcgdGhhdCBzaG91bGQgYmUgZml4ZWQgb24gaXRzIG93bi4gQml0 cyB0aGF0IGFyZSBSQVovV0kgaW4KdGhlIGFyY2hpdGVjdHVyZSBzaG91bGRuJ3QgYmUga2VwdCBp biB0aGUgc2hhZG93IHJlZ2lzdGVycyB0aGUgZmlyc3QKcGxhY2UuIEknbGwgaGF2ZSBhIGxvb2su Cgo+IFNvIEkgd2lsbCByZXN1Ym1pdCBpbml0aWFsIHBhdGNoLCB3aXRoIGp1c3QgdGhlIGNvbW1p dCBtZXNzYWdlCj4gY2hhbmdlcy4KClBsZWFzZSBkb24ndC4gSSdtIG5vdCBwYXBlcmluZyBvdmVy IHRoaXMga2luZCBvZiBidWcuCgpUaGFua3MsCgoJTS4KCi0tIApXaXRob3V0IGRldmlhdGlvbiBm cm9tIHRoZSBub3JtLCBwcm9ncmVzcyBpcyBub3QgcG9zc2libGUuCgpfX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1haWxpbmcg bGlzdApsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmlu ZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg==