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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7E53C433FE for ; Thu, 3 Nov 2022 06:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229531AbiKCGGu (ORCPT ); Thu, 3 Nov 2022 02:06:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230231AbiKCGGs (ORCPT ); Thu, 3 Nov 2022 02:06:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F19A419C23 for ; Wed, 2 Nov 2022 23:06:46 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 678CC61D43 for ; Thu, 3 Nov 2022 06:06:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91C28C433C1; Thu, 3 Nov 2022 06:06:45 +0000 (UTC) Date: Thu, 3 Nov 2022 02:06:43 -0400 From: Steven Rostedt To: Dave Jiang Cc: linux-cxl@vger.kernel.org, dan.j.williams@intel.com, ira.weiny@intel.com, vishal.l.verma@intel.com, alison.schofield@intel.com Subject: Re: [PATCH v3 05/10] cxl: add monitor function for event trace events Message-ID: <20221103020643.6ac71b93@rorschach.local.home> In-Reply-To: <166742403256.2654617.15551316837123337120.stgit@djiang5-desk3.ch.intel.com> References: <166742389426.2654617.4404053893427481848.stgit@djiang5-desk3.ch.intel.com> <166742403256.2654617.15551316837123337120.stgit@djiang5-desk3.ch.intel.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Wed, 02 Nov 2022 14:20:32 -0700 Dave Jiang wrote: > --- > cxl/meson.build | 1 > cxl/monitor.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 141 insertions(+) > create mode 100644 cxl/monitor.c > > diff --git a/cxl/meson.build b/cxl/meson.build > index c59876262e76..eb8b2b1070ed 100644 > --- a/cxl/meson.build > +++ b/cxl/meson.build > @@ -8,6 +8,7 @@ cxl_src = [ > 'json.c', > 'filter.c', > 'event_trace.c', > + 'monitor.c', > ] > > cxl_tool = executable('cxl', > diff --git a/cxl/monitor.c b/cxl/monitor.c > new file mode 100644 > index 000000000000..85559d9a4b94 > --- /dev/null > +++ b/cxl/monitor.c > @@ -0,0 +1,140 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright (C) 2022, Intel Corp. All rights reserved. > +/* Some bits copied from ndctl monitor code */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* reuse the core log helpers for the monitor logger */ > +#ifndef ENABLE_LOGGING > +#define ENABLE_LOGGING > +#endif > +#ifndef ENABLE_DEBUG > +#define ENABLE_DEBUG > +#endif > +#include > + > +#include "event_trace.h" > + > +static const char *cxl_system = "cxl"; > + > +static struct monitor { > + struct log_ctx ctx; > + FILE *log_file; > + bool human; > +} monitor; > + > +static int monitor_event(struct cxl_ctx *ctx) > +{ > + int fd, epollfd, rc = 0, timeout = -1; > + struct epoll_event ev, *events; > + struct tracefs_instance *inst; > + struct event_ctx ectx; > + int jflag; > + > + events = calloc(1, sizeof(struct epoll_event)); > + if (!events) { > + err(&monitor, "alloc for events error\n"); > + return -ENOMEM; > + } > + > + epollfd = epoll_create1(0); > + if (epollfd == -1) { > + rc = -errno; > + err(&monitor, "epoll_create1() error: %d\n", rc); > + goto epoll_err; > + } > + > + inst = tracefs_instance_create("cxl_monitor"); > + if (!inst) { > + rc = -errno; > + err(&monitor, "tracefs_instance_crate( failed: %d\n", rc); "crate"? Been coding a bit too much Rust lately? > + goto inst_err; > + } > + > + fd = tracefs_instance_file_open(inst, "trace_pipe", -1); I'm curious to why you are opening trace_pipe? > + if (fd < 0) { > + rc = fd; > + err(&monitor, "tracefs_instance_file_open() err: %d\n", rc); > + goto inst_file_err; > + } > + > + memset(&ev, 0, sizeof(ev)); > + ev.events = EPOLLIN; > + ev.data.fd = fd; Is it a way to know if there's something to read? -- Steve > + > + if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) != 0) { > + rc = -errno; > + err(&monitor, "epoll_ctl() error: %d\n", rc); > + goto epoll_ctl_err; > + } > + > + rc = cxl_event_tracing_enable(inst, cxl_system); > + if (rc < 0) { > + err(&monitor, "cxl_trace_event_enable() failed: %d\n", rc); > + goto event_en_err; > + } > + > + memset(&ectx, 0, sizeof(ectx)); > + ectx.system = cxl_system; > + if (monitor.human) > + jflag = JSON_C_TO_STRING_PRETTY; > + else > + jflag = JSON_C_TO_STRING_PLAIN; > + > + while (1) { > + struct jlist_node *jnode, *next; > + > + rc = epoll_wait(epollfd, events, 1, timeout); > + if (rc < 0) { > + rc = -errno; > + if (errno != EINTR) > + err(&monitor, "epoll_wait error: %d\n", -errno); > + break; > + } > + > + list_head_init(&ectx.jlist_head); > + rc = cxl_parse_events(inst, &ectx); > + if (rc < 0) > + goto parse_err; > + > + if (list_empty(&ectx.jlist_head)) > + continue; > + > + list_for_each_safe(&ectx.jlist_head, jnode, next, list) { > + notice(&monitor, "%s\n", > + json_object_to_json_string_ext(jnode->jobj, jflag)); > + list_del(&jnode->list); > + json_object_put(jnode->jobj); > + free(jnode); > + } > + } > + > +parse_err: > + rc = cxl_event_tracing_disable(inst); > +event_en_err: > +epoll_ctl_err: > + close(fd); > +inst_file_err: > + tracefs_instance_free(inst); > +inst_err: > + close(epollfd); > +epoll_err: > + free(events); > + return rc; > +} >