From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 3E59DC433DB for ; Thu, 4 Feb 2021 17:06:08 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DCBFC64F3C for ; Thu, 4 Feb 2021 17:06:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DCBFC64F3C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42764 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l7i50-0005qH-P2 for qemu-devel@archiver.kernel.org; Thu, 04 Feb 2021 12:06:06 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41060) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l7hgf-0001Wr-Ml for qemu-devel@nongnu.org; Thu, 04 Feb 2021 11:40:58 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:40557) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l7hgd-000515-TV for qemu-devel@nongnu.org; Thu, 04 Feb 2021 11:40:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612456855; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Se5PgBvmj/igHU2KtSDhk45/M6qHCrQMbFcqOM72qf0=; b=H50tWOV4b2yvRt81D5pHKm/WfP/ECMzDCFKcdRGbISzW9qJI34Wl/minge3ZGuNYf4cUJZ vMTU2WdcfnlV9TciTYRsBcT6S6R2ooAE76LylxLWCey5Pg3tBS0EAzeh6ZOoMeop+xEONm MGK3WSIrBfbMEHu0DGoR6+txPynjUSM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-376-yo2veudPNyO7C1FyLyqDBw-1; Thu, 04 Feb 2021 11:40:53 -0500 X-MC-Unique: yo2veudPNyO7C1FyLyqDBw-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 12505100C611; Thu, 4 Feb 2021 16:40:52 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-114-21.ams2.redhat.com [10.36.114.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D5871A38C; Thu, 4 Feb 2021 16:40:46 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, andrey.gruzdev@virtuozzo.com, berrange@redhat.com, gaojinhao@huawei.com, armbru@redhat.com, mst@redhat.com, philmd@redhat.com, wainersm@redhat.com Subject: [PULL 09/27] migration: introduce 'userfaultfd-wrlat.py' script Date: Thu, 4 Feb 2021 16:39:41 +0000 Message-Id: <20210204163959.377618-10-dgilbert@redhat.com> In-Reply-To: <20210204163959.377618-1-dgilbert@redhat.com> References: <20210204163959.377618-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=63.128.21.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.351, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Andrey Gruzdev Add BCC/eBPF script to analyze userfaultfd write fault latency distribution. Signed-off-by: Andrey Gruzdev Reviewed-by: Peter Xu Message-Id: <20210129101407.103458-6-andrey.gruzdev@virtuozzo.com> Signed-off-by: Dr. David Alan Gilbert --- scripts/userfaultfd-wrlat.py | 122 +++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100755 scripts/userfaultfd-wrlat.py diff --git a/scripts/userfaultfd-wrlat.py b/scripts/userfaultfd-wrlat.py new file mode 100755 index 0000000000..0684be4e04 --- /dev/null +++ b/scripts/userfaultfd-wrlat.py @@ -0,0 +1,122 @@ +#!/usr/bin/python3 +# +# userfaultfd-wrlat Summarize userfaultfd write fault latencies. +# Events are continuously accumulated for the +# run, while latency distribution histogram is +# dumped each 'interval' seconds. +# +# For Linux, uses BCC, eBPF. +# +# USAGE: userfaultfd-lat [interval [count]] +# +# Copyright Virtuozzo GmbH, 2020 +# +# Authors: +# Andrey Gruzdev +# +# This work is licensed under the terms of the GNU GPL, version 2 or +# later. See the COPYING file in the top-level directory. + +from __future__ import print_function +from bcc import BPF +from ctypes import c_ushort, c_int, c_ulonglong +from time import sleep +from sys import argv + +def usage(): + print("USAGE: %s [interval [count]]" % argv[0]) + exit() + +# define BPF program +bpf_text = """ +#include +#include + +BPF_HASH(ev_start, u32, u64); +BPF_HISTOGRAM(ev_delta_hist, u64); + +/* Trace UFFD page fault start event. */ +static void do_event_start() +{ + /* Using "(u32)" to drop group ID which is upper 32 bits */ + u32 tid = (u32) bpf_get_current_pid_tgid(); + u64 ts = bpf_ktime_get_ns(); + + ev_start.update(&tid, &ts); +} + +/* Trace UFFD page fault end event. */ +static void do_event_end() +{ + /* Using "(u32)" to drop group ID which is upper 32 bits */ + u32 tid = (u32) bpf_get_current_pid_tgid(); + u64 ts = bpf_ktime_get_ns(); + u64 *tsp; + + tsp = ev_start.lookup(&tid); + if (tsp) { + u64 delta = ts - (*tsp); + /* Transform time delta to milliseconds */ + ev_delta_hist.increment(bpf_log2l(delta / 1000000)); + ev_start.delete(&tid); + } +} + +/* KPROBE for handle_userfault(). */ +int probe_handle_userfault(struct pt_regs *ctx, struct vm_fault *vmf, + unsigned long reason) +{ + /* Trace only UFFD write faults. */ + if (reason & VM_UFFD_WP) { + do_event_start(); + } + return 0; +} + +/* KRETPROBE for handle_userfault(). */ +int retprobe_handle_userfault(struct pt_regs *ctx) +{ + do_event_end(); + return 0; +} +""" + +# arguments +interval = 10 +count = -1 +if len(argv) > 1: + try: + interval = int(argv[1]) + if interval == 0: + raise + if len(argv) > 2: + count = int(argv[2]) + except: # also catches -h, --help + usage() + +# load BPF program +b = BPF(text=bpf_text) +# attach KRPOBEs +b.attach_kprobe(event="handle_userfault", fn_name="probe_handle_userfault") +b.attach_kretprobe(event="handle_userfault", fn_name="retprobe_handle_userfault") + +# header +print("Tracing UFFD-WP write fault latency... Hit Ctrl-C to end.") + +# output +loop = 0 +do_exit = 0 +while (1): + if count > 0: + loop += 1 + if loop > count: + exit() + try: + sleep(interval) + except KeyboardInterrupt: + pass; do_exit = 1 + + print() + b["ev_delta_hist"].print_log2_hist("msecs") + if do_exit: + exit() -- 2.29.2