From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A0E6F49636 for ; Wed, 3 Jul 2024 21:41:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720042892; cv=none; b=tF4eS4nV5GmHQaLVjgrDvxALU86fKzkOL2QcvOj7p/ydBZrpDymWAm8Ch0tXXshEtvYayCZLZGkYY3D2Fi7wItG6IfXkaAN7uR/1VLtoQnUwB1r1BL+Vlr7CrFSihDF8RxdnbOn3QudteDWTD1p/BYCyYhI+5gc5VgsJoBUSsz0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720042892; c=relaxed/simple; bh=1AOIWxxOBWX5vh1jRAP/DmyIESd9L2fe3ew2irm+bHE=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=swhdXRBWua0A61UvjBbygYI07BA7GZhp1RpwRZ7WvpccOSaEBDaBRnR5sEm8vvmWj4mponogdMjn26tYdjCdbdjdWs3YixLS+R6hTdt598WN6PT6+QwY++R/E2daz/xCzu9Mh9awbALWb8nw9TiwDk2AkVfMTVq2+5YNF4Ecwac= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D106C2BD10; Wed, 3 Jul 2024 21:41:31 +0000 (UTC) Date: Wed, 3 Jul 2024 17:41:29 -0400 From: Steven Rostedt To: Yang Jialong =?UTF-8?B?5p2o5L2z6b6Z?= Cc: mhiramat@kernel.org, Karol Herbst , Pekka Paalanen , mathieu.desnoyers@efficios.com, Michael Ellerman , linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 1/2] powerpc/mmiotrace: Add MMIO Tracing tool for PowerPC Message-ID: <20240703174129.7e19a9a6@rorschach.local.home> In-Reply-To: <5F5B4CCA07D939BE+1a8b7985-b0c6-4b03-8c31-d1281f7b56e4@shingroup.cn> References: <2CCFA0BD64E5F2E0+e4c7fc43-47b1-4788-a7d2-44f6a33cff66@shingroup.cn> <5F5B4CCA07D939BE+1a8b7985-b0c6-4b03-8c31-d1281f7b56e4@shingroup.cn> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Wed, 3 Jul 2024 15:39:09 +0800 Yang Jialong =E6=9D=A8=E4=BD=B3=E9=BE=99 wrote: > Hello, mmiotrace maintainers. >=20 > Here is a first version patch used to support mmiotrace function on=20 > powerpc platform. When I copy mmiotrace to powerpc archtecture, we found= =20 > that there are many code are general, such as code in kmmio.c and=20 > mmio-mod.c in arch/x86/mm/.=C2=A0 But we have file trace_mmiotrace.c as a= low=20 > layer to finish the function. Whether we can abstract out one layer=20 > again or not? >=20 The mmiotracer is at a minimal maintenance level. I constantly test it and make sure it works (on x86) for every pull request I do. But I haven't done much more than that. If I ever got the time, I was going to make it work for SMP machines, as it currently still requires running in UP (does a CPU hotplug to shutdown all CPUs but one when enabled). But that's just because there was no effort to make it multiprocessor safe. It is definitely doable. But it is very low priority in my TODO list. I have no problem if you want to clean it up and pull out the more generic parts. Hey, if you have time, make it SMP safe if you can ;-) Although that may remove one of my biggest bug finders. You'd be amazed at what breaks when you aggressively disable all but one CPU and then enable all of them back up again. -- Steve