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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B54B1C83F16 for ; Sat, 26 Aug 2023 08:13:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231408AbjHZIMg (ORCPT ); Sat, 26 Aug 2023 04:12:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229764AbjHZIMP (ORCPT ); Sat, 26 Aug 2023 04:12:15 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8501C1FD7; Sat, 26 Aug 2023 01:12:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1693037530; x=1693642330; i=deller@gmx.de; bh=hm1F3N09SJ+WGgO0vYyvNvla2f7QTLVFBvCg3MxxSCo=; h=X-UI-Sender-Class:Date:Subject:To:Cc:References:From:In-Reply-To; b=oYiYBoZFErgc1j45ACFKyinCnwtftKkPXzUuXZNsQ3GEtEjdoZfe3NiqzS3eeDFzwHhCjB+ pJyV4eWZIdl1aN08SNVtba/gULQwsP0q6HtAUoyeWP1D2K4IP4FmJkFIH2rpesjjC34sXUdO1 sjjmqx0Piw+llAJQ19kjHS5+DcDGviiBIXXdEcTDnWUBjk1Uo9/DYIZ4JHgsUvMdDH4EbKWJy 27duX+7gACT+4ypLiJ178xMcLmOiWw84GEpWpseyln9ReKTIrlUGJ1wXvmRUHoqoWXtPvbDx8 hrpIJAhDQM0JsiS8mkb+It3va7U/91U5IR92J6GmcC0OW0T876ww== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [192.168.20.60] ([94.134.144.244]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1Md6R1-1q0kQr0s6t-00aF3g; Sat, 26 Aug 2023 10:12:10 +0200 Message-ID: Date: Sat, 26 Aug 2023 10:12:09 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH 1/3] parisc: led: Reduce CPU overhead for disk & lan LED computation Content-Language: en-US To: Greg KH Cc: linux-parisc@vger.kernel.org, stable@vger.kernel.org References: <20230825180928.205499-1-deller@kernel.org> <2023082636-refreeze-plot-9f6e@gregkh> <15c20ace-62c9-a986-cb68-f74953bef624@gmx.de> <2023082605-vista-probably-faac@gregkh> From: Helge Deller In-Reply-To: <2023082605-vista-probably-faac@gregkh> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:iGoVkgBijaEutkD1CRFkxYCy7VLZgWn3iBSeaxdIJomcYNDkaey c1+D4EohHsQPulUzHTDiwCEhu4erorhktfGd275dHBXQwtS8GF+GYj/gUZylBkT8djnf2Eq 87nIhU8hl8uKbLRuJKiHoFXDDmGAE1GZ0PzlCskvWq7ewu82Rf+o5czDi0aILEithZYP9Ys vSmRDBHpl36Z3BMlqYniw== UI-OutboundReport: notjunk:1;M01:P0:olqhuQ1V458=;sF5dNz4EvTLEvk6WwSSfUrbLEEA n8M+RpZETPhF/Ii9Z1etHW753xgieEriXGzuwELxVm/wXIGBsrGWB6f4g/zsVd3GkBrZQYtT1 yU8q3ELM/OKwudRcgAhLH7U/EH1pdWiE0Nqzm1lp89EQOuVv89Labq49o69PqNe4cotpEFfGP uKRRJwRUu3HU3zIkA+28R4Bqq47I1Gis8crt2soHPOQOh8ykVzjgXud6wMbOdNk9KyKM62Nu+ VKRXYtxrRNO0JHKqSVX8Ih9b7Ey/dP4ouoGUQIxdCHkUGSYWz1wW/sq+ij607Z5pcyWlKxCNO kt4936+ZojfVxSxSttdB6r8AGCYmRYJ4719/Z7ndZ2vZo2pUsRf3dwsTDu95BlpdIlm1FQr4m aCFq3JRMRwu5A2n1+AYsa/8GUJpHqVT+aHDAzpcn4hVWi5BNoNNRqEKbiWgdYg4d2pOcCZ2cz XoU+1F2gDOWRX6Tcnfpw76dA0kdDzpJp1F4IQ+X/NRnW6poHaVgF07a5FtCKdhxBPjvEI1lD7 F2wtvbzLgDu2tDzgq5w8ri1GBYf4oWuB0etHHSoXnq7aRLmmHCHbBV3ycDfbyGooGfHQnhg3V 00gw1cJ1ZzcmHSvvk5AnRGjo0WdC+aG+D1UUt8Sx8Wl/zg42C6jyT9SXoN3mOXDCBP2n46a3t rJjGT5VYNDqETNy8QshZgJn0nDozNRWrQh/xjKFxvpbbSs0EKYwdn/xCmwyKJGPKhbQTORQR6 OK4vgNLucKsDHdSP7gXa9Ssq4+YZj9/B0r9HzjlcQcQvObICnlgLShL6l8y19YUGVnW+A73iA 9tnGR/f0Hc/qaDDrstjVKgN7rtsmt+peVv4sKhDKjNgDwDhADzQSsjVSW0RGFAtY0VZVtYOaM EzLxpezWDJ+NR67C518dnvSFjYidkPg1zGGRxUil3mbfJ8p5l0Rz8iNf+zvVpMWXb9LdUHfqk nvvOk8OwaUd1B2/BsMDe8P4LB3w= Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On 8/26/23 09:58, Greg KH wrote: > On Sat, Aug 26, 2023 at 09:54:55AM +0200, Helge Deller wrote: >> On 8/26/23 09:34, Greg KH wrote: >>> On Fri, Aug 25, 2023 at 08:09:26PM +0200, deller@kernel.org wrote: >>>> From: Helge Deller >>>> >>>> Older PA-RISC machines have LEDs which show the disk- and LAN-activit= y. >>>> The computation is done in software and takes quite some time, e.g. o= n a >>>> J6500 this may take up to 60% time of one CPU if the machine is loade= d >>>> via network traffic. >>>> >>>> Since most people don't care about the LEDs, start with LEDs disabled= and >>>> just show a CPU heartbeat LED. The disk and LAN LEDs can be turned on >>>> manually via /proc/pdc/led. >>>> >>>> Signed-off-by: Helge Deller >>>> Cc: >>>> --- >>>> drivers/parisc/led.c | 7 +++++-- >>>> 1 file changed, 5 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c >>>> index 8bdc5e043831..765f19608f60 100644 >>>> --- a/drivers/parisc/led.c >>>> +++ b/drivers/parisc/led.c >>>> @@ -56,8 +56,8 @@ >>>> static int led_type __read_mostly =3D -1; >>>> static unsigned char lastleds; /* LED state from most recent updat= e */ >>>> static unsigned int led_heartbeat __read_mostly =3D 1; >>>> -static unsigned int led_diskio __read_mostly =3D 1; >>>> -static unsigned int led_lanrxtx __read_mostly =3D 1; >>>> +static unsigned int led_diskio __read_mostly; >>>> +static unsigned int led_lanrxtx __read_mostly; >>>> static char lcd_text[32] __read_mostly; >>>> static char lcd_text_default[32] __read_mostly; >>>> static int lcd_no_led_support __read_mostly =3D 0; /* KittyHaw= k doesn't support LED on its LCD */ >>>> @@ -589,6 +589,9 @@ int __init register_led_driver(int model, unsigne= d long cmd_reg, unsigned long d >>>> return 1; >>>> } >>>> >>>> + pr_info("LED: Enable disk and LAN activity LEDs " >>>> + "via /proc/pdc/led\n"); >>> >>> When drivers are working properly, they should be quiet. Who is going >>> to see this message? >> >> That patch shouldn't have gone to stable@ yet... git-send-patch just >> pulled the CC in and I didn't noticed. >> So, please don't apply it yet. > > I will not, and it's fine to cc: stable@ on stuff that is still making > it's way into the kernel tree. It gives us a heads-up on stuff, AND > sometimes it gives you an additional free review :) Yes, thanks! :-) >>> I don't even understand it, are you saying that you now need to go >>> enable the led through proc? And why are leds in proc, I thought they >>> had a real class for them? Why not use that instead? >> >> This is an old driver from the very beginning, and I don't want to chan= ge >> much in it for old kernels other than to reduce the CPU overhead it gen= erates. > > Ah, makes sense, that is a crazy amount of cpu time for a blinking led. > > How about just default to it off (like the first chunk you have here), > which will go to stable trees, Yes, that was the idea of this patch. I'll drop the pr_info() next time. > and then a rewrite to use the proper LED api? Yes. Helge