From mboxrd@z Thu Jan 1 00:00:00 1970 From: Karim Yaghmour Subject: Re: [RFC PATCH lttng-modules] LTTng logger ABI Date: Mon, 17 Feb 2014 10:09:37 -0500 Message-ID: <53022631.90209__30644.3808753558$1392649852$gmane$org@opersys.com> References: <1392502096-1900-1-git-send-email-mathieu.desnoyers@efficios.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qc0-f180.google.com ([209.85.216.180]) by ltt.polymtl.ca with esmtp (Exim 4.72) (envelope-from ) id 1WFPpI-0002nb-Gu for lttng-dev@lists.lttng.org; Mon, 17 Feb 2014 10:09:50 -0500 Received: by mail-qc0-f180.google.com with SMTP id i17so24320555qcy.11 for ; Mon, 17 Feb 2014 07:09:39 -0800 (PST) In-Reply-To: <1392502096-1900-1-git-send-email-mathieu.desnoyers@efficios.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: lttng-dev-bounces@lists.lttng.org To: Mathieu Desnoyers Cc: lttng-dev@lists.lttng.org List-Id: lttng-dev@lists.lttng.org That was quick :) On 14-02-15 05:08 PM, Mathieu Desnoyers wrote: > Add a user-space ABI (new file /proc/lttng-logger) to lttng-modules > which can be written into by any user on the system. The content is > saved into the kernel trace stream into the "lttng_logger" kernel event. Nice. I think this would do for the use-case we discussed (i.e. feedback Android's "ATRACE" events into lttng instead of ftrace's "trace_marker" file.) > The content of a single write is written into an lttng_logger event, > provided the packet size is large enough to store the content. If it is > not large enough, it won't be logged. However we cannot return any error > to the caller, since there may be more than one trace session listening > to this event. Can we just truncate instead of dropping if the event is too large? -- Karim Yaghmour CEO - Opersys inc. / www.opersys.com http://twitter.com/karimyaghmour