Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755489Ab2HVInz (ORCPT ); Wed, 22 Aug 2012 04:43:55 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:60326 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755084Ab2HVIng (ORCPT ); Wed, 22 Aug 2012 04:43:36 -0400 X-AuditID: b753bd60-8f6bfba0000047ca-56-50349bb5207e X-AuditID: b753bd60-8f6bfba0000047ca-56-50349bb5207e From: Yoshihiro YUNOMAE Subject: [PATCH 3/5] trace-cmd: Support trace-agent of virtio-trace To: Steven Rostedt Cc: Amit Shah , Anthony Liguori , Arnd Bergmann , Borislav Petkov , "Franch Ch. Eigler" , Frederic Weisbecker , Greg Kroah-Hartman , Herbert Xu , Ingo Molnar , Masami Hiramatsu , Mathieu Desnoyers , Rusty Russell , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org, yrl.pp-manager.tt@hitachi.com, Yoshihiro YUNOMAE Date: Wed, 22 Aug 2012 17:43:22 +0900 Message-ID: <20120822084322.17293.70186.stgit@ltc189.sdl.hitachi.co.jp> In-Reply-To: <20120822084251.17293.69086.stgit@ltc189.sdl.hitachi.co.jp> References: <20120822084251.17293.69086.stgit@ltc189.sdl.hitachi.co.jp> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5002 Lines: 186 Add read path and control path to use trace-agent of virtio-trace. When we use trace-agent, trace-cmd will be used as follows: # AGENT_READ_DIR=/tmp/virtio-trace/tracing \ AGENT_CTL=/tmp/virtio-trace/agent-ctl-path.in \ TRACING_DIR=/tmp/virtio-trace/debugfs/tracing \ trace-cmd record -e "sched:*" Here, AGENT_READ_DIR is the path for a reading directory of virtio-trace, AGENT_CTL is a control path of trace-agent, and TRACING_DIR is a debugfs path of a guest. Signed-off-by: Yoshihiro YUNOMAE --- trace-cmd.h | 1 + trace-recorder.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++- trace-util.c | 18 +++++++++++++++++ 3 files changed, 75 insertions(+), 1 deletions(-) diff --git a/trace-cmd.h b/trace-cmd.h index f904dc5..75506ed 100644 --- a/trace-cmd.h +++ b/trace-cmd.h @@ -72,6 +72,7 @@ static inline int tracecmd_host_bigendian(void) } char *tracecmd_find_tracing_dir(void); +char *guest_agent_tracing_read_dir(void); /* --- Opening and Reading the trace.dat file --- */ diff --git a/trace-recorder.c b/trace-recorder.c index 215affc..3b750e9 100644 --- a/trace-recorder.c +++ b/trace-recorder.c @@ -33,6 +33,7 @@ #include #include #include +#include #include "trace-cmd.h" @@ -43,6 +44,8 @@ struct tracecmd_recorder { int page_size; int cpu; int stop; + int ctl_fd; + bool agent_existing; }; void tracecmd_free_recorder(struct tracecmd_recorder *recorder) @@ -59,11 +62,29 @@ void tracecmd_free_recorder(struct tracecmd_recorder *recorder) free(recorder); } +static char *use_trace_agent_dir(char *ctl_path, + struct tracecmd_recorder *recorder) +{ + ctl_path = strdup(ctl_path); + if (!ctl_path) + die("malloc"); + warning("Use environmental control path: %s\n", ctl_path); + + recorder->ctl_fd = open(ctl_path, O_WRONLY); + if (recorder->ctl_fd < 0) + return NULL; + + recorder->agent_existing = true; + + return guest_agent_tracing_read_dir(); +} + struct tracecmd_recorder *tracecmd_create_recorder_fd(int fd, int cpu) { struct tracecmd_recorder *recorder; char *tracing = NULL; char *path = NULL; + char *ctl_path = NULL; int ret; recorder = malloc_or_die(sizeof(*recorder)); @@ -76,12 +97,23 @@ struct tracecmd_recorder *tracecmd_create_recorder_fd(int fd, int cpu) recorder->trace_fd = -1; recorder->brass[0] = -1; recorder->brass[1] = -1; + recorder->ctl_fd = -1; + recorder->agent_existing = false; recorder->page_size = getpagesize(); recorder->fd = fd; - tracing = tracecmd_find_tracing_dir(); + /* + * The trace-agent on a guest is controlled to run or stop by a host, + * so we need to assign the control path of the trace-agent to use + * virtio-trace. + */ + ctl_path = getenv("AGENT_CTL"); + if (ctl_path) + tracing = use_trace_agent_dir(ctl_path, recorder); + else + tracing = tracecmd_find_tracing_dir(); if (!tracing) { errno = ENODEV; goto out_free; @@ -182,6 +214,24 @@ long tracecmd_flush_recording(struct tracecmd_recorder *recorder) return total; } +static void operation_to_trace_agent(int ctl_fd, bool run_agent) +{ + if (run_agent == true) + write(ctl_fd, "1", 2); + else + write(ctl_fd, "0", 2); +} + +static void run_operation_to_trace_agent(int ctl_fd) +{ + operation_to_trace_agent(ctl_fd, true); +} + +static void stop_operation_to_trace_agent(int ctl_fd) +{ + operation_to_trace_agent(ctl_fd, false); +} + int tracecmd_start_recording(struct tracecmd_recorder *recorder, unsigned long sleep) { struct timespec req; @@ -189,6 +239,9 @@ int tracecmd_start_recording(struct tracecmd_recorder *recorder, unsigned long s recorder->stop = 0; + if (recorder->agent_existing) + run_operation_to_trace_agent(recorder->ctl_fd); + do { if (sleep) { req.tv_sec = sleep / 1000000; @@ -214,6 +267,8 @@ void tracecmd_stop_recording(struct tracecmd_recorder *recorder) if (!recorder) return; + if (recorder->agent_existing) + stop_operation_to_trace_agent(recorder->ctl_fd); recorder->stop = 1; } diff --git a/trace-util.c b/trace-util.c index d5a3eb4..ff639be 100644 --- a/trace-util.c +++ b/trace-util.c @@ -304,6 +304,24 @@ static int mount_debugfs(void) return ret; } +char *guest_agent_tracing_read_dir(void) +{ + char *tracing_read_dir; + + tracing_read_dir = getenv("AGENT_READ_DIR"); + if (tracing_read_dir) { + tracing_read_dir = strdup(tracing_read_dir); + if (!tracing_read_dir) + die("malloc"); + warning("Use environmental read directory of trace-agent: %s\n", + tracing_read_dir); + return tracing_read_dir; + } + + warning("AGENT_READ_DIR was not declared"); + return NULL; +} + char *tracecmd_find_tracing_dir(void) { char debugfs[MAX_PATH+1]; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/