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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A419FC433EF for ; Fri, 1 Oct 2021 15:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8831A61ACF for ; Fri, 1 Oct 2021 15:57:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231794AbhJAP7g (ORCPT ); Fri, 1 Oct 2021 11:59:36 -0400 Received: from linux.microsoft.com ([13.77.154.182]:37122 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231434AbhJAP7f (ORCPT ); Fri, 1 Oct 2021 11:59:35 -0400 Received: from kbox (unknown [24.17.193.74]) by linux.microsoft.com (Postfix) with ESMTPSA id 04A8B20B8008; Fri, 1 Oct 2021 08:57:51 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 04A8B20B8008 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1633103871; bh=L+hTirf2j5Nmu4ftJs5tmkbZpphyA9Gv2h6o4DaLNCw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YOOIg2G2JUKz8vunSF/eCpzCgpiMQwZBTcgaCBNm7+3Q2MF+6XH2kFr2mj/Bb0R4e CgOCFHQngtMbE9LEvoUMQt+k6+tpJGYDMBg4R+/dyaU66Mib6pn4rpTq/BaBuhHXKI quDH+rLcQ2NPT5ywcijiYomn8gVEY85IyUFWV2Qk= Date: Fri, 1 Oct 2021 08:57:46 -0700 From: Beau Belgrave To: Masami Hiramatsu Cc: linux-trace-devel@VGER.KERNEL.ORG, rostedt@goodmis.org, zanussi@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] synth_events: Do not block other dyn_event systems during create Message-ID: <20211001155746.GA16348@kbox> References: <20210930223821.11025-1-beaub@linux.microsoft.com> <20211001125513.cf40fa1a3188416582666f66@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211001125513.cf40fa1a3188416582666f66@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org > Thanks for clean up the synthetic event! > This looks good to me. > > Reviewed-by: Masami Hiramatsu No problem, thanks for the review! > So now are you trying to reuse synth event for user event? > Then I think you need to register a new dyn_event ops so > that histogram will not submit the event. A user events patch will get sent out soon, I'm finalizing some testing. User events will register it's own dyn_event ops and allow users the option to create, delete and view status of user events via the dynamic_events tracefs file (in addition to the user mode IOCTL/ABI). As probes attach to the user events the status of this is reflected in dynamic_events, which makes it easy for admins to see why one is busy, etc. It also makes it easy to verifying the system is working as expected with just a terminal. > BTW, how do you filter an event written by a user process? > Will you add an array of event id for the file data structure? The filtering would happen at the trace_event level, the only filtering at the user event level is if a probe has been enabled on the underlying trace_event or not. That is done via the shared page bits being cleared or set. Bits are updated as probe un/registrations occur. Users can advertise field values, offsets, etc as well as the print_fmt in the newer ABI/patch based on the feedback from LPC2021. These land in the trace_event fields and are viewable via tracefs like any other evnet. I hope that is enough to light up the history feature of trace_event. I am not familiar with it as much as you all. Thanks, -Beau