From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CEB1C373C12; Wed, 20 May 2026 23:56:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779321422; cv=none; b=gWzEz3PbGWIYE5Hi0EayrNYCoSEwdLZg4iTxlFd7eGKt6utb9fp7xIYv6nCOIJCgvb2qz4FuvuwkOVaVjfbcUgMu6A7Q1UKi26kISTPuUSDESZiyWs4eSEeHY6alEo/LyONP6tl7RgpYNLuwSKrCuAETMyOKpOH9fI4muvnlhGs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779321422; c=relaxed/simple; bh=jTiku2mluObpXzBa1NiYoGfbUZnqEbOOqXCo232N2ic=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=U5xgvZqGxjg8AizWjGEtd6CP8Wi2w7IiwYl/tsTAq1iO6HahdU5EGpAT8zmUex5S9E76Fpc/oabLC1bjV7HNd/4ipRIuSwmYfrUmksf5pOI7pzOFtYQAh5LSxbfli5XEp4+/riNIrJsiZFJe2pLeycClb3m7aOanuFLar+omVfc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=casper.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=OmqFRRZQ; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=casper.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="OmqFRRZQ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=MIME-Version:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=jTiku2mluObpXzBa1NiYoGfbUZnqEbOOqXCo232N2ic=; b=OmqFRRZQxWH9gzIjOn8pJhyobz C/mp6rFHZg1NTyyb93fxGkowyb/YRrFZpHytaXexnnLEveykpofuINlf4eX5iNcrxif81LIQ/Ytl6 fSQI40Xtuxn0JO9omehm7eJkFr4rPrezzqu+ZupbtcgD8FEsmxD5ui4dK84+jabLaD6vKUfa1Mlrh P+X8Xc1jWuK9mAT5dnoungd3495qh8Y/++RA5MYy7/g//9h3PDg2Pxm5RjR97sdBmIQCnFuNizGs8 KvUCOyXar9Ui6dq+fLstukIZuFA0BiRM//wvGhJxNz3sTH+uXPnNX/m6uqXkPP1phSwk796LOWE8r 09QEtjJQ==; Received: from 54-240-197-235.amazon.com ([54.240.197.235] helo=freeip.amazon.com) by casper.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPqmO-00000007lg2-1peW; Wed, 20 May 2026 23:56:48 +0000 Message-ID: <715e3b725b87e96d9733c5565cb00f97b03e6485.camel@infradead.org> Subject: Re: [PATCH v3 37/41] x86/kvmclock: Use TSC for sched_clock if it's constant and non-stop From: David Woodhouse To: Sean Christopherson , Kiryl Shutsemau , Paolo Bonzini , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Ajay Kaher , Alexey Makhalov , Jan Kiszka , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Juergen Gross , Daniel Lezcano , Thomas Gleixner , John Stultz Cc: Rick Edgecombe , Vitaly Kuznetsov , Broadcom internal kernel review list , Boris Ostrovsky , Stephen Boyd , x86@kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, Michael Kelley , Tom Lendacky , Nikunj A Dadhania , Thomas Gleixner Date: Thu, 21 May 2026 00:56:46 +0100 In-Reply-To: <20260515191942.1892718-38-seanjc@google.com> References: <20260515191942.1892718-1-seanjc@google.com> <20260515191942.1892718-38-seanjc@google.com> Content-Type: multipart/signed; micalg="sha-256"; protocol="application/pkcs7-signature"; boundary="=-kKUdfWK5Ck2wirAYsNEp" User-Agent: Evolution 3.52.3-0ubuntu1.1 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html --=-kKUdfWK5Ck2wirAYsNEp Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2026-05-15 at 12:19 -0700, Sean Christopherson wrote: > Prefer the TSC over kvmclock for sched_clock if the TSC is constant, > nonstop, and not marked unstable via command line.=C2=A0 I.e. use the sam= e > criteria as tweaking the clocksource rating so that TSC is preferred over > kvmclock.=C2=A0 Per the below comment from native_sched_clock(), sched_cl= ock > is more tolerant of slop than clocksource; using TSC for clocksource but > not sched_clock makes little to no sense, especially now that KVM CoCo > guests with a trusted TSC use TSC, not kvmclock. >=20 > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * Fall back to jiffies i= f there's no TSC available: > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * ( But note that we sti= ll use it if the TSC is marked > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *=C2=A0=C2=A0 unstable. = We do this because unlike Time Of Day, > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *=C2=A0=C2=A0 the schedu= ler clock tolerates small errors and it's > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *=C2=A0=C2=A0 very impor= tant for it to be as fast as the platform > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *=C2=A0=C2=A0 can achiev= e it. ) > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 */ >=20 > The only advantage of using kvmclock is that doing so allows for early > and common detection of PVCLOCK_GUEST_STOPPED, but that code has been > broken for over two years with nary a complaint, i.e. it can't be > _that_ valuable.=C2=A0 And as above, certain types of KVM guests are losi= ng > the functionality regardless, i.e. acknowledging PVCLOCK_GUEST_STOPPED > needs to be decoupled from sched_clock() no matter what. >=20 > Link: https://lore.kernel.org/all/Z4hDK27OV7wK572A@google.com > Signed-off-by: Sean Christopherson Yay! (Albeit only for sched_clock, and we should do Xen too) Reviewed-by: David Woodhouse --=-kKUdfWK5Ck2wirAYsNEp Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCD9Aw ggSOMIIDdqADAgECAhAOmiw0ECVD4cWj5DqVrT9PMA0GCSqGSIb3DQEBCwUAMGUxCzAJBgNVBAYT AlVTMRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxGTAXBgNVBAsTEHd3dy5kaWdpY2VydC5jb20xJDAi BgNVBAMTG0RpZ2lDZXJ0IEFzc3VyZWQgSUQgUm9vdCBDQTAeFw0yNDAxMzAwMDAwMDBaFw0zMTEx MDkyMzU5NTlaMEExCzAJBgNVBAYTAkFVMRAwDgYDVQQKEwdWZXJva2V5MSAwHgYDVQQDExdWZXJv a2V5IFNlY3VyZSBFbWFpbCBHMjCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMjvgLKj jfhCFqxYyRiW8g3cNFAvltDbK5AzcOaR7yVzVGadr4YcCVxjKrEJOgi7WEOH8rUgCNB5cTD8N/Et GfZI+LGqSv0YtNa54T9D1AWJy08ZKkWvfGGIXN9UFAPMJ6OLLH/UUEgFa+7KlrEvMUupDFGnnR06 aDJAwtycb8yXtILj+TvfhLFhafxroXrflspavejQkEiHjNjtHnwbZ+o43g0/yxjwnarGI3kgcak7 nnI9/8Lqpq79tLHYwLajotwLiGTB71AGN5xK+tzB+D4eN9lXayrjcszgbOv2ZCgzExQUAIt98mre 8EggKs9mwtEuKAhYBIP/0K6WsoMnQCcCAwEAAaOCAVwwggFYMBIGA1UdEwEB/wQIMAYBAf8CAQAw HQYDVR0OBBYEFIlICOogTndrhuWByNfhjWSEf/xwMB8GA1UdIwQYMBaAFEXroq/0ksuCMS1Ri6en IZ3zbcgPMA4GA1UdDwEB/wQEAwIBhjAdBgNVHSUEFjAUBggrBgEFBQcDBAYIKwYBBQUHAwIweQYI KwYBBQUHAQEEbTBrMCQGCCsGAQUFBzABhhhodHRwOi8vb2NzcC5kaWdpY2VydC5jb20wQwYIKwYB BQUHMAKGN2h0dHA6Ly9jYWNlcnRzLmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEFzc3VyZWRJRFJvb3RD QS5jcnQwRQYDVR0fBD4wPDA6oDigNoY0aHR0cDovL2NybDMuZGlnaWNlcnQuY29tL0RpZ2lDZXJ0 QXNzdXJlZElEUm9vdENBLmNybDARBgNVHSAECjAIMAYGBFUdIAAwDQYJKoZIhvcNAQELBQADggEB ACiagCqvNVxOfSd0uYfJMiZsOEBXAKIR/kpqRp2YCfrP4Tz7fJogYN4fxNAw7iy/bPZcvpVCfe/H /CCcp3alXL0I8M/rnEnRlv8ItY4MEF+2T/MkdXI3u1vHy3ua8SxBM8eT9LBQokHZxGUX51cE0kwa uEOZ+PonVIOnMjuLp29kcNOVnzf8DGKiek+cT51FvGRjV6LbaxXOm2P47/aiaXrDD5O0RF5SiPo6 xD1/ClkCETyyEAE5LRJlXtx288R598koyFcwCSXijeVcRvBB1cNOLEbg7RMSw1AGq14fNe2cH1HG W7xyduY/ydQt6gv5r21mDOQ5SaZSWC/ZRfLDuEYwggWbMIIEg6ADAgECAhAH5JEPagNRXYDiRPdl c1vgMA0GCSqGSIb3DQEBCwUAMEExCzAJBgNVBAYTAkFVMRAwDgYDVQQKEwdWZXJva2V5MSAwHgYD VQQDExdWZXJva2V5IFNlY3VyZSBFbWFpbCBHMjAeFw0yNDEyMzAwMDAwMDBaFw0yODAxMDQyMzU5 NTlaMB4xHDAaBgNVBAMME2R3bXcyQGluZnJhZGVhZC5vcmcwggIiMA0GCSqGSIb3DQEBAQUAA4IC DwAwggIKAoICAQDali7HveR1thexYXx/W7oMk/3Wpyppl62zJ8+RmTQH4yZeYAS/SRV6zmfXlXaZ sNOE6emg8WXLRS6BA70liot+u0O0oPnIvnx+CsMH0PD4tCKSCsdp+XphIJ2zkC9S7/yHDYnqegqt w4smkqUqf0WX/ggH1Dckh0vHlpoS1OoxqUg+ocU6WCsnuz5q5rzFsHxhD1qGpgFdZEk2/c//ZvUN i12vPWipk8TcJwHw9zoZ/ZrVNybpMCC0THsJ/UEVyuyszPtNYeYZAhOJ41vav1RhZJzYan4a1gU0 kKBPQklcpQEhq48woEu15isvwWh9/+5jjh0L+YNaN0I//nHSp6U9COUG9Z0cvnO8FM6PTqsnSbcc 0j+GchwOHRC7aP2t5v2stVx3KbptaYEzi4MQHxm/0+HQpMEVLLUiizJqS4PWPU6zfQTOMZ9uLQRR ci+c5xhtMEBszlQDOvEQcyEG+hc++fH47K+MmZz21bFNfoBxLP6bjR6xtPXtREF5lLXxp+CJ6KKS blPKeVRg/UtyJHeFKAZXO8Zeco7TZUMVHmK0ZZ1EpnZbnAhKE19Z+FJrQPQrlR0gO3lBzuyPPArV hvWxjlO7S4DmaEhLzarWi/ze7EGwWSuI2eEa/8zU0INUsGI4ywe7vepQz7IqaAovAX0d+f1YjbmC VsAwjhLmveFjNwIDAQABo4IBsDCCAawwHwYDVR0jBBgwFoAUiUgI6iBOd2uG5YHI1+GNZIR//HAw HQYDVR0OBBYEFFxiGptwbOfWOtMk5loHw7uqWUOnMDAGA1UdEQQpMCeBE2R3bXcyQGluZnJhZGVh ZC5vcmeBEGRhdmlkQHdvb2Rob3Uuc2UwFAYDVR0gBA0wCzAJBgdngQwBBQEBMA4GA1UdDwEB/wQE AwIF4DAdBgNVHSUEFjAUBggrBgEFBQcDAgYIKwYBBQUHAwQwewYDVR0fBHQwcjA3oDWgM4YxaHR0 cDovL2NybDMuZGlnaWNlcnQuY29tL1Zlcm9rZXlTZWN1cmVFbWFpbEcyLmNybDA3oDWgM4YxaHR0 cDovL2NybDQuZGlnaWNlcnQuY29tL1Zlcm9rZXlTZWN1cmVFbWFpbEcyLmNybDB2BggrBgEFBQcB AQRqMGgwJAYIKwYBBQUHMAGGGGh0dHA6Ly9vY3NwLmRpZ2ljZXJ0LmNvbTBABggrBgEFBQcwAoY0 aHR0cDovL2NhY2VydHMuZGlnaWNlcnQuY29tL1Zlcm9rZXlTZWN1cmVFbWFpbEcyLmNydDANBgkq hkiG9w0BAQsFAAOCAQEAQXc4FPiPLRnTDvmOABEzkIumojfZAe5SlnuQoeFUfi+LsWCKiB8Uextv iBAvboKhLuN6eG/NC6WOzOCppn4mkQxRkOdLNThwMHW0d19jrZFEKtEG/epZ/hw/DdScTuZ2m7im 8ppItAT6GXD3aPhXkXnJpC/zTs85uNSQR64cEcBFjjoQDuSsTeJ5DAWf8EMyhMuD8pcbqx5kRvyt JPsWBQzv1Dsdv2LDPLNd/JUKhHSgr7nbUr4+aAP2PHTXGcEBh8lTeYea9p4d5k969pe0OHYMV5aL xERqTagmSetuIwolkAuBCzA9vulg8Y49Nz2zrpUGfKGOD0FMqenYxdJHgDCCBZswggSDoAMCAQIC EAfkkQ9qA1FdgOJE92VzW+AwDQYJKoZIhvcNAQELBQAwQTELMAkGA1UEBhMCQVUxEDAOBgNVBAoT B1Zlcm9rZXkxIDAeBgNVBAMTF1Zlcm9rZXkgU2VjdXJlIEVtYWlsIEcyMB4XDTI0MTIzMDAwMDAw MFoXDTI4MDEwNDIzNTk1OVowHjEcMBoGA1UEAwwTZHdtdzJAaW5mcmFkZWFkLm9yZzCCAiIwDQYJ KoZIhvcNAQEBBQADggIPADCCAgoCggIBANqWLse95HW2F7FhfH9bugyT/danKmmXrbMnz5GZNAfj Jl5gBL9JFXrOZ9eVdpmw04Tp6aDxZctFLoEDvSWKi367Q7Sg+ci+fH4KwwfQ8Pi0IpIKx2n5emEg nbOQL1Lv/IcNiep6Cq3DiyaSpSp/RZf+CAfUNySHS8eWmhLU6jGpSD6hxTpYKye7PmrmvMWwfGEP WoamAV1kSTb9z/9m9Q2LXa89aKmTxNwnAfD3Ohn9mtU3JukwILRMewn9QRXK7KzM+01h5hkCE4nj W9q/VGFknNhqfhrWBTSQoE9CSVylASGrjzCgS7XmKy/BaH3/7mOOHQv5g1o3Qj/+cdKnpT0I5Qb1 nRy+c7wUzo9OqydJtxzSP4ZyHA4dELto/a3m/ay1XHcpum1pgTOLgxAfGb/T4dCkwRUstSKLMmpL g9Y9TrN9BM4xn24tBFFyL5znGG0wQGzOVAM68RBzIQb6Fz758fjsr4yZnPbVsU1+gHEs/puNHrG0 9e1EQXmUtfGn4InoopJuU8p5VGD9S3Ikd4UoBlc7xl5yjtNlQxUeYrRlnUSmdlucCEoTX1n4UmtA 9CuVHSA7eUHO7I88CtWG9bGOU7tLgOZoSEvNqtaL/N7sQbBZK4jZ4Rr/zNTQg1SwYjjLB7u96lDP sipoCi8BfR35/ViNuYJWwDCOEua94WM3AgMBAAGjggGwMIIBrDAfBgNVHSMEGDAWgBSJSAjqIE53 a4blgcjX4Y1khH/8cDAdBgNVHQ4EFgQUXGIam3Bs59Y60yTmWgfDu6pZQ6cwMAYDVR0RBCkwJ4ET ZHdtdzJAaW5mcmFkZWFkLm9yZ4EQZGF2aWRAd29vZGhvdS5zZTAUBgNVHSAEDTALMAkGB2eBDAEF AQEwDgYDVR0PAQH/BAQDAgXgMB0GA1UdJQQWMBQGCCsGAQUFBwMCBggrBgEFBQcDBDB7BgNVHR8E dDByMDegNaAzhjFodHRwOi8vY3JsMy5kaWdpY2VydC5jb20vVmVyb2tleVNlY3VyZUVtYWlsRzIu Y3JsMDegNaAzhjFodHRwOi8vY3JsNC5kaWdpY2VydC5jb20vVmVyb2tleVNlY3VyZUVtYWlsRzIu Y3JsMHYGCCsGAQUFBwEBBGowaDAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AuZGlnaWNlcnQuY29t MEAGCCsGAQUFBzAChjRodHRwOi8vY2FjZXJ0cy5kaWdpY2VydC5jb20vVmVyb2tleVNlY3VyZUVt YWlsRzIuY3J0MA0GCSqGSIb3DQEBCwUAA4IBAQBBdzgU+I8tGdMO+Y4AETOQi6aiN9kB7lKWe5Ch 4VR+L4uxYIqIHxR7G2+IEC9ugqEu43p4b80LpY7M4KmmfiaRDFGQ50s1OHAwdbR3X2OtkUQq0Qb9 6ln+HD8N1JxO5nabuKbymki0BPoZcPdo+FeRecmkL/NOzzm41JBHrhwRwEWOOhAO5KxN4nkMBZ/w QzKEy4PylxurHmRG/K0k+xYFDO/UOx2/YsM8s138lQqEdKCvudtSvj5oA/Y8dNcZwQGHyVN5h5r2 nh3mT3r2l7Q4dgxXlovERGpNqCZJ624jCiWQC4ELMD2+6WDxjj03PbOulQZ8oY4PQUyp6djF0keA MYIDuzCCA7cCAQEwVTBBMQswCQYDVQQGEwJBVTEQMA4GA1UEChMHVmVyb2tleTEgMB4GA1UEAxMX VmVyb2tleSBTZWN1cmUgRW1haWwgRzICEAfkkQ9qA1FdgOJE92VzW+AwDQYJYIZIAWUDBAIBBQCg ggE3MBgGCSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTI2MDUyMDIzNTY0 NlowLwYJKoZIhvcNAQkEMSIEIM9loCje2QWEUjYKijElvo8yzcwgkPQMdL24rVbDPC0gMGQGCSsG AQQBgjcQBDFXMFUwQTELMAkGA1UEBhMCQVUxEDAOBgNVBAoTB1Zlcm9rZXkxIDAeBgNVBAMTF1Zl cm9rZXkgU2VjdXJlIEVtYWlsIEcyAhAH5JEPagNRXYDiRPdlc1vgMGYGCyqGSIb3DQEJEAILMVeg VTBBMQswCQYDVQQGEwJBVTEQMA4GA1UEChMHVmVyb2tleTEgMB4GA1UEAxMXVmVyb2tleSBTZWN1 cmUgRW1haWwgRzICEAfkkQ9qA1FdgOJE92VzW+AwDQYJKoZIhvcNAQEBBQAEggIAe9sYCjW1zvtz Qy+0v2MMDFUQg9QthxzyiIbxtO2k7JykRo4PmqeYd07vZsbSXmFXktKKx8OXA59HGw0gbGEi+ck8 wqBCTzmPq1NucwNPGWTPLk3FrNCq9VVV+SRtFeC285PsWOy1WM9GfBiG7zxp/WJffdyO/poXeQ4S 2VPU9jXqi338Boi8NnMk5qHd3zXjmMAuTqyQgZIUDTGYPjmHmX7TWsNI9wj9Q/n6oPbbZhWfBNUj ocaiyj1vruL08SlV5Z8lVrDiPNAUrS9qpMbcXM27HvbhH5Lhk/b2WUneKzQmeqGpCdM50CUquBxN w9uOv2mkce2QQlOFocdjTJGvvVsrXtw4Csr3CnZCVqF5UhNZ9lnLLqHq0J94EGG+2Q//BkYAhNmR gQCGyWRohkbePfpGbCytEHEjgyJ4FTXCpRhysCSOcGgTUn2IzKcHdevSu1jsYBcRTQlE2fH1LKib bRB+9EAVW1f/aSN1MreqZa6I2vN6gG3cvVrwK8N0l8f7CGMf5V9a9gQdFTQwbLuzI0CZR0lk0IQl 63ZcVQYQul/UKtU/S0wr8YSaK7v+w9R+5+vpRzyQJsn7lnMK+JCKj5afD4NHCV/FCu9KMLeV0/pF FlTtDIOL7ivwaN73b9LT3eh5qY6uGu5gC56G+wAPZV+BngTUmNQccjVacSEIFOIAAAAAAAA= --=-kKUdfWK5Ck2wirAYsNEp--