From patchwork Fri Oct 28 00:27:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13022943 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 40CD4FA3743 for ; Fri, 28 Oct 2022 00:27:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233187AbiJ1A1u (ORCPT ); Thu, 27 Oct 2022 20:27:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234665AbiJ1A1t (ORCPT ); Thu, 27 Oct 2022 20:27:49 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE693A232A for ; Thu, 27 Oct 2022 17:27:47 -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 ams.source.kernel.org (Postfix) with ESMTPS id A01C9B82840 for ; Fri, 28 Oct 2022 00:27:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CF64C43470; Fri, 28 Oct 2022 00:27:45 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1ooDE9-00DoYt-05; Thu, 27 Oct 2022 20:28:01 -0400 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: "Steven Rostedt (Google)" Subject: [PATCH 2/3] libtracefs: Add man pages for tracefs_cpu_alloc_fd() and tracefs_cpu_free_fd() Date: Thu, 27 Oct 2022 20:27:57 -0400 Message-Id: <20221028002758.3285764-3-rostedt@goodmis.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221028002758.3285764-1-rostedt@goodmis.org> References: <20221028002758.3285764-1-rostedt@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Steven Rostedt (Google)" Update the man pages to describe the tracefs_cpu_alloc_fd() and tracefs_cpu_free_fd(). Signed-off-by: Steven Rostedt (Google) --- Documentation/libtracefs-cpu-open.txt | 24 +++++++++++++++++++++++- Documentation/libtracefs.txt | 2 ++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/Documentation/libtracefs-cpu-open.txt b/Documentation/libtracefs-cpu-open.txt index 58dde508290d..c5a900a06e8e 100644 --- a/Documentation/libtracefs-cpu-open.txt +++ b/Documentation/libtracefs-cpu-open.txt @@ -3,7 +3,7 @@ libtracefs(3) NAME ---- -tracefs_cpu_open, tracefs_cpu_close - Opening trace_pipe_raw data for reading +tracefs_cpu_open, tracefs_cpu_close, tracefs_cpu_alloc_fd, tracefs_cpu_free_fd - Opening trace_pipe_raw data for reading SYNOPSIS -------- @@ -14,6 +14,9 @@ SYNOPSIS struct tracefs_cpu pass:[*]*tracefs_cpu_open*(struct tracefs_instance pass:[*]_instance_, int _cpu_, bool _nonblock_); void *tracefs_cpu_close*(struct tracefs_cpu pass:[*]_tcpu_); + +struct tracefs_cpu pass:[*]*tracefs_cpu_alloc_fd*(int _fd_, int _subbuf_size_, bool _nonblock_); +void *tracefs_cpu_free_fd*(struct tracefs_cpu pass:[*]_tcpu_); -- DESCRIPTION @@ -29,11 +32,30 @@ NULL than the toplevel trace_pipe_raw file is used. The *tracefs_cpu_close()* closes all the file descriptors associated to the trace_pipe_raw opened by *tracefs_cpu_open()*. +The *tracefs_cpu_alloc_fd()* will create a tracefs_cpu descriptor from an existing +file descriptor _fd_. This is useful to use when connecting to a socket or pipe where +the other end is feeding raw tracing data in the same format as the trace_pipe_raw +file would (like in guest to host tracing). The caller is responsible for determining +the _subbuf_size_ that will be used to break up the sub-buffers being read by the +file descriptor. The _nonblock_ is treated the same as the same parameter in +*tracefs_cpu_open()*. + +The *tracefs_cpu_free_fd()* is used to free the descriptor returned by *tracefs_cpu_alloc_fd()*. +It does all the clean up that *tracefs_cpu_close()* performs, and that could also be +used to free up the descriptor created by *tracefs_cpu_alloc_fd()* but will also close +the file descriptor passed in. Note that *tracefs_cpu_free_fd()* should not be used +on the descriptor returned by *tracefs_cpu_open()* as it will not close the file descriptor +created by it. + RETURN VALUE ------------ The *tracefs_cpu_open()* returns a struct tracefs_cpu descriptor that can be used by the other functions or NULL on error. +The *tracefs_cpu_alloc_fd()* returns a struct tracefs_cpu descriptor that can +be used by the *tracefs_cpu_read*(3) related functions, where the descriptor +will be reading the passed in _fd_ file descriptor. + EXAMPLE ------- See *tracefs_cpu_read*(3) for an example. diff --git a/Documentation/libtracefs.txt b/Documentation/libtracefs.txt index d41c7ab382ee..50af23e33026 100644 --- a/Documentation/libtracefs.txt +++ b/Documentation/libtracefs.txt @@ -270,7 +270,9 @@ Histograms: Recording of trace_pipe_raw files: struct tracefs_cpu pass:[*]*tracefs_cpu_open*(struct tracefs_instance pass:[*]_instance_, int _cpu_, bool _nonblock_); + struct tracefs_cpu pass:[*]*tracefs_cpu_alloc_fd*(int _fd_, int _subbuf_size_, bool _nonblock_); void *tracefs_cpu_close*(struct tracefs_cpu pass:[*]_tcpu_); + void *tracefs_cpu_free_fd*(struct tracefs_cpu pass:[*]_tcpu_); int *tracefs_cpu_read_size*(struct tracefs_cpu pass:[*]_tcpu_); int *tracefs_cpu_read*(struct tracefs_cpu pass:[*]_tcpu_, void pass:[*]_buffer_, bool _nonblock_); int *tracefs_cpu_buffered_read*(struct tracefs_cpu pass:[*]_tcpu_, void pass:[*]_buffer_, bool _nonblock_);