From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752629AbdJ3Ip0 (ORCPT ); Mon, 30 Oct 2017 04:45:26 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39658 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752138AbdJ3IpY (ORCPT ); Mon, 30 Oct 2017 04:45:24 -0400 Date: Mon, 30 Oct 2017 09:45:37 +0100 From: Greg KH To: Vitaly Kuznetsov Cc: kys@microsoft.com, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, leann.ogasawara@canonical.com, marcelo.cerri@canonical.com, sthemmin@microsoft.com Subject: Re: [PATCH 10/17] hyper-v: trace vmbus_open() Message-ID: <20171030084537.GA14865@kroah.com> References: <20171029192030.12356-1-kys@exchange.microsoft.com> <20171029192116.12466-1-kys@exchange.microsoft.com> <20171029192116.12466-10-kys@exchange.microsoft.com> <20171029205958.GA30187@kroah.com> <877evdyrsc.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <877evdyrsc.fsf@vitty.brq.redhat.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 30, 2017 at 09:16:19AM +0100, Vitaly Kuznetsov wrote: > Greg KH writes: > > > On Sun, Oct 29, 2017 at 12:21:09PM -0700, kys@exchange.microsoft.com wrote: > >> From: Vitaly Kuznetsov > >> > >> Add tracepoint to CHANNELMSG_OPENCHANNEL sender. > >> > >> Signed-off-by: Vitaly Kuznetsov > >> Signed-off-by: K. Y. Srinivasan > >> --- > >> drivers/hv/channel.c | 2 ++ > >> drivers/hv/hv_trace.h | 27 +++++++++++++++++++++++++++ > >> 2 files changed, 29 insertions(+) > >> > >> diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c > >> index a406beb10dd0..739b3fe1e0fb 100644 > >> --- a/drivers/hv/channel.c > >> +++ b/drivers/hv/channel.c > >> @@ -185,6 +185,8 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, > >> ret = vmbus_post_msg(open_msg, > >> sizeof(struct vmbus_channel_open_channel), true); > >> > >> + trace_vmbus_open(open_msg, ret); > > > > Why add tracepoints for things that ftrace can handle automatically? > > This series adds pretty prints for structures printing what is needed > and in the right format significantly simplifying debugging. And it > wouldn't make sense to add tracepoints to *some* messages-related > functions and skip others where parsing is more trivial. Tracepoints add memory usage and take up real space. If you don't need them for something, as there are other ways to already get the information needed, why add new ones that you now need to drag around for all time? thanks greg k-h