From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 19B3F1DB125 for ; Fri, 14 Feb 2025 21:07:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739567280; cv=none; b=nKEioNm0U3KTysen28c2JJEQF3FUZa3vxZuSgdzpcFBxb3FJNr0FwKDYrTAkNE4j33ewjfgzNOYQNzeDKxjoGUVqisECYq2J/AuI+wPRI06A89FZhD/+Cr4wZjSoyrAEXljCVP/8bfkpucafIDAS3qor6df3Vwcywizid7xJZlM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739567280; c=relaxed/simple; bh=cTD0YGxM7C/r8VmscZOvQcLrBnZIJ/Bl8PiAHhMhK5s=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=DI46sG/VLaip52S9tWTGAn1+rOxQRSekPPztme1u8CS83zGTJ2D8g/ej0Zw0HubU/BNHIvDQQb4uujJP4JjHf9I5z9gxFkTp7/ldVYVWLk6MvOynVt3Tfrk8x8L9aKY7/SH8Pd4vUL0hLRuJTnUzUdE+dbGCu7dqJtM3Q7tVL7Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=CfkFnYqS; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CfkFnYqS" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-220ee2e7746so23260785ad.2 for ; Fri, 14 Feb 2025 13:07:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1739567278; x=1740172078; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=fK9Grk2+mxUxJmbNSyLNP4j/EN3bbR5J+pxd4ldMHvY=; b=CfkFnYqSuxjoUgaDCgJA2MIXe+8G9DbmV7yG8Jsu4YXkiJVTBCkObzvBjJYf6fRu0o 9ow4ZgkFRLH8JaGTytYkb9a1Zc52JSB8Zxrs/byGBGO7GJFg4kjcI7QlUoDttbySGUrX jvgW98GeozYwa8671Ks1yTb6PGihFZsltsg0lVArp6W+OXDGtLZaBI9YZ3eXfGvlV2ow azFsljwdQdJJc2kot0GXCF4jv8fX5A5mACffAZlDtNTs/auVJ3oZnDuPBcDWUzg1+9IP LfsEFrHcDx788Tv8gcxkbKePH05kSIVbgcXuC1u/X5mpqsHdmOHBG5rf0PcuLyhM1OsO +zAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739567278; x=1740172078; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=fK9Grk2+mxUxJmbNSyLNP4j/EN3bbR5J+pxd4ldMHvY=; b=LUpdf+mZ+W60pWhJQcsVALGNhrIMvJQLFUxDN+SL5ycOZLSNnTY3GeaQgG2l2hqE/R 9PwG2CY6NQXPvXFUBtr8JvN66UtXM8jaYkTAWO8UxhDn+KvMmEq0FP6eB9Lna3jjHEjA bPd2E/loaXO59X8Gxpx/j7qwky8dujUmp72zwqbntfFJKmjtKyXZa7aON8RD6SI4u/N5 Qx2xD+/lbib4fGImNy0ULgfIn5WiNkwVedQwBR9/T0ErOA3tnxkRc5Zz+njJpMyCHb0J +7jwXNfqLu5PhVz13kEAK3LRgzagUqTSKExohhZZVgjAILBiPg9PX/v88ySBCWsbURP/ G/KQ== X-Forwarded-Encrypted: i=1; AJvYcCVf+L02BDP3Q2Oa3AnuEgDPG4h5/VaCR9CVKyHkQbShcRcKdkhhN4hSAT6t83065NRQ0DRv+J2hNgdye1M=@vger.kernel.org X-Gm-Message-State: AOJu0YyklpHIujXZboe3uOGDw86WuW7JOu/yWC4Oc+CPORrnUxTFiMo+ S7xljKL66clnioihm8LApisCQpPpxH99rDDCJufkw2w9g4DX9fagPPE38+KcB0MpxfHZxdxjTG/ j0w== X-Google-Smtp-Source: AGHT+IEB9kfMbLqDRiIWrvbRpSDJvL2ukP7ELBGl34NRPGn22tun5wCq6W7V3vW6ase9xSQ5LQ5KsjA0YD0= X-Received: from pfbga8.prod.google.com ([2002:a05:6a00:6208:b0:725:e4b6:901f]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:394b:b0:1ee:1af5:86a9 with SMTP id adf61e73a8af0-1ee8cb17bbcmr2046257637.22.1739567278334; Fri, 14 Feb 2025 13:07:58 -0800 (PST) Date: Fri, 14 Feb 2025 13:07:57 -0800 In-Reply-To: <20240914101728.33148-9-dapeng1.mi@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240914101728.33148-1-dapeng1.mi@linux.intel.com> <20240914101728.33148-9-dapeng1.mi@linux.intel.com> Message-ID: Subject: Re: [kvm-unit-tests patch v6 08/18] x86: pmu: Fix cycles event validation failure From: Sean Christopherson To: Dapeng Mi Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Jim Mattson , Mingwei Zhang , Xiong Zhang , Zhenyu Wang , Like Xu , Jinrong Liang , Yongwei Ma , Dapeng Mi Content-Type: text/plain; charset="us-ascii" On Sat, Sep 14, 2024, Dapeng Mi wrote: > +static void warm_up(void) > +{ > + int i = 8; > + > + /* > + * Since cycles event is always run as the first event, there would be > + * a warm-up state to warm up the cache, it leads to the measured cycles > + * value may exceed the pre-defined cycles upper boundary and cause > + * false positive. To avoid this, introduce an warm-up state before > + * the real verification. > + */ > + while (i--) > + loop(); Use a for-loop. > +} > + > static void check_counters(void) > { > if (is_fep_available()) > check_emulated_instr(); > > + warm_up(); > check_gp_counters(); > check_fixed_counters(); > check_rdpmc(); > -- > 2.40.1 >