From patchwork Mon Aug 2 16:56:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jing Zhang X-Patchwork-Id: 12414431 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62E74C4338F for ; Mon, 2 Aug 2021 16:56:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44ED7610FF for ; Mon, 2 Aug 2021 16:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230214AbhHBQ4v (ORCPT ); Mon, 2 Aug 2021 12:56:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229879AbhHBQ4u (ORCPT ); Mon, 2 Aug 2021 12:56:50 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B079C061760 for ; Mon, 2 Aug 2021 09:56:40 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id p1-20020a17090a3481b029017757e8c762so539224pjb.1 for ; Mon, 02 Aug 2021 09:56:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=n7kvyUwvmN2lWlXICtvoUP2GwE5hnziRhEMEYcR9kvU=; b=Zc72S8MgPQ6tqfASIqWQtoZnFmBJaUhfzOCzTiZpGvzciT1q4orsWxy53rNUX1+lDc Ub82uoOX1yR3ES1G5uwHdK0O2uy3yzUEkQC+35W/8YuvK/QaJmtn2/4kLzURnFVgySFr zJl5uReeaL8XAddh5HspCI7nuX4Ahs4DRREEDpHanIhjtUAYtM/5rgpzmLJF3SPSeWHR kVMfdfJwDDPnTg3OnRObEDKE2ShQZaLDb2I5XADdhnb5O/SAcqpn6OP3v5SulsxLoiCj vx2Xqr9NxmK6+A2BwGpYXD2ITaRVdT7dwF5M7jlIR7wugacn0krGjHPy+nr4kT+whSHW EFpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=n7kvyUwvmN2lWlXICtvoUP2GwE5hnziRhEMEYcR9kvU=; b=i16xorfXSMIdc5uxbCpJj504Slc4d7pR1fWqS+gQvh/C94e7JMQ87PFKTrwRKkWLyM mvNhHVwh+uChiLmlNjzMl3uQ8Xfvwhi6xLU4sxkSdiMCC+wzlx7a10xpOPUa3iVyeCJC jj8vSpmg0I2OnBwgO5fbJRiKxdRIJF9q3kI1QZX3ABXdX4NpgJ2MyCcB/RX6dqTkBf17 6Zqf62P2jfloJPODypTethe+6WA1lHRW9153/bdWcBNB6T5mUOk7wjiJVgC58VzZtPgs tcLd/bGlO1ZT6KdjTX0fOWnXsgV62G6yMAhBUX0UtVUscJCGWexjy/m+r5RmdzuuRBdz v+7Q== X-Gm-Message-State: AOAM5326wfHyj0lu7HinWLghOW0lZtBbDCmI5gJYvwUuIbnuf3JJf92e IbdlcXdAFk/J913Yh8wnuuLadiMovYZbAh06sTg7H58Ffqc99huBLSd5ot5Uyb+qBtfSW+SuqqJ ME75Mgl2cpCjMExVQnxH8g1g2wkFYPmIDBhDR78CyFJgcuHgiK0BEiWfx8fNYhLAAYhEYaes= X-Google-Smtp-Source: ABdhPJwE3IZTCnHS7M6tPiGGDshf1eVqEiN0WFQv+g3f61Q+ROt5ht6ZfF3loZzdCm1wGVlE878ZbfVA+10kRckunA== X-Received: from jgzg.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:1acf]) (user=jingzhangos job=sendgmr) by 2002:a63:25c7:: with SMTP id l190mr2972782pgl.165.1627923399710; Mon, 02 Aug 2021 09:56:39 -0700 (PDT) Date: Mon, 2 Aug 2021 16:56:30 +0000 In-Reply-To: <20210802165633.1866976-1-jingzhangos@google.com> Message-Id: <20210802165633.1866976-3-jingzhangos@google.com> Mime-Version: 1.0 References: <20210802165633.1866976-1-jingzhangos@google.com> X-Mailer: git-send-email 2.32.0.554.ge1b32706d8-goog Subject: [PATCH v3 2/5] KVM: stats: Update doc for histogram statistics From: Jing Zhang To: KVM , KVMPPC , Paolo Bonzini , Sean Christopherson , Jim Mattson , Peter Shier , Oliver Upton , David Rientjes , David Matlack Cc: Jing Zhang Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add documentations for linear and logarithmic histogram statistics. Signed-off-by: Jing Zhang --- Documentation/virt/kvm/api.rst | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index dae68e68ca23..095a32f968c6 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -5207,6 +5207,9 @@ by a string of size ``name_size``. #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT) #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT) #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT) + #define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT) + #define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT) + #define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST #define KVM_STATS_UNIT_SHIFT 4 #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT) @@ -5214,18 +5217,20 @@ by a string of size ``name_size``. #define KVM_STATS_UNIT_BYTES (0x1 << KVM_STATS_UNIT_SHIFT) #define KVM_STATS_UNIT_SECONDS (0x2 << KVM_STATS_UNIT_SHIFT) #define KVM_STATS_UNIT_CYCLES (0x3 << KVM_STATS_UNIT_SHIFT) + #define KVM_STATS_UNIT_MAX KVM_STATS_UNIT_CYCLES #define KVM_STATS_BASE_SHIFT 8 #define KVM_STATS_BASE_MASK (0xF << KVM_STATS_BASE_SHIFT) #define KVM_STATS_BASE_POW10 (0x0 << KVM_STATS_BASE_SHIFT) #define KVM_STATS_BASE_POW2 (0x1 << KVM_STATS_BASE_SHIFT) + #define KVM_STATS_BASE_MAX KVM_STATS_BASE_POW2 struct kvm_stats_desc { __u32 flags; __s16 exponent; __u16 size; __u32 offset; - __u32 unused; + __u32 bucket_size; char name[]; }; @@ -5250,6 +5255,21 @@ Bits 0-3 of ``flags`` encode the type: represents a peak value for a measurement, for example the maximum number of items in a hash table bucket, the longest time waited and so on. The corresponding ``size`` field for this type is always 1. + * ``KVM_STATS_TYPE_LINEAR_HIST`` + The statistics data is in the form of linear histogram. The number of + buckets is specified by the ``size`` field. The size of buckets is specified + by the ``hist_param`` field. The range of the Nth bucket (1 <= N < ``size``) + is [``hist_param``*(N-1), ``hist_param``*N), while the range of the last + bucket is [``hist_param``*(``size``-1), +INF). (+INF means positive infinity + value.) The bucket value indicates how many times the statistics data is in + the bucket's range. + * ``KVM_STATS_TYPE_LOG_HIST`` + The statistics data is in the form of logarithmic histogram. The number of + buckets is specified by the ``size`` field. The range of the first bucket is + [0, 1), while the range of the last bucket is [pow(2, ``size``-2), +INF). + Otherwise, The Nth bucket (1 < N < ``size``) covers + [pow(2, N-2), pow(2, N-1)). The bucket value indicates how many times the + statistics data is in the bucket's range. Bits 4-7 of ``flags`` encode the unit: * ``KVM_STATS_UNIT_NONE`` @@ -5282,9 +5302,9 @@ unsigned 64bit data. The ``offset`` field is the offset from the start of Data Block to the start of the corresponding statistics data. -The ``unused`` field is reserved for future support for other types of -statistics data, like log/linear histogram. Its value is always 0 for the types -defined above. +The ``bucket_size`` field is used as a parameter for histogram statistics data. +It is only used by linear histogram statistics data, specifying the size of a +bucket. The ``name`` field is the name string of the statistics data. The name string starts at the end of ``struct kvm_stats_desc``. The maximum length including