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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 647AEC433EF for ; Tue, 19 Jun 2018 16:33:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0429E20661 for ; Tue, 19 Jun 2018 16:33:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0429E20661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967082AbeFSQdo (ORCPT ); Tue, 19 Jun 2018 12:33:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:52032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966692AbeFSQdc (ORCPT ); Tue, 19 Jun 2018 12:33:32 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 34DFB20020; Tue, 19 Jun 2018 16:33:31 +0000 (UTC) Date: Tue, 19 Jun 2018 12:33:29 -0400 From: Steven Rostedt To: "Matwey V. Kornilov" Cc: hverkuil@xs4all.nl, mchehab@kernel.org, mingo@redhat.com, Mike Isely , Bhumika Goyal , Colin King , linux-media@vger.kernel.org, open list Subject: Re: [PATCH 1/2] Add TRACE_EVENTs in pwc_isoc_handler() Message-ID: <20180619123329.52bf6216@gandalf.local.home> In-Reply-To: References: <20180617143625.32133-1-matwey@sai.msu.ru> <20180618145854.2092c6e0@gandalf.local.home> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 19 Jun 2018 19:23:04 +0300 "Matwey V. Kornilov" wrote: > Hi Steven, > > Thank you for valuable comments. > > This is for measuring performance of URB completion callback inside PWC driver. > What do you think about moving events to __usb_hcd_giveback_urb() in > order to make this more generic? Like the following: > > local_irq_save(flags); > // trace urb complete enter > urb->complete(urb); > // trace urb complete exit > local_irq_restore(flags); > > If that can work for you, I'm fine with that. Trace events may be cheap, but they do come with some cost. I'd like to have all trace events be as valuable as possible, and limit the "special case" ones. -- Steve