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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 80B8EC3A5A2 for ; Mon, 19 Aug 2019 14:38:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60527206C1 for ; Mon, 19 Aug 2019 14:38:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726820AbfHSOip (ORCPT ); Mon, 19 Aug 2019 10:38:45 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:49710 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbfHSOip (ORCPT ); Mon, 19 Aug 2019 10:38:45 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id D573480BA7; Mon, 19 Aug 2019 16:38:29 +0200 (CEST) Date: Mon, 19 Aug 2019 16:38:42 +0200 From: Pavel Machek To: Jacek Anaszewski Cc: Akinobu Mita , linux-block@vger.kernel.org, linux-leds@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, Frank Steiner , Dan Murphy , Jens Axboe , "James E.J. Bottomley" , "Martin K. Petersen" , Hannes Reinecke Subject: Re: [PATCH v4 4/5] block: introduce LED block device activity trigger Message-ID: <20190819143842.GA25401@amd> References: <1565888399-21550-1-git-send-email-akinobu.mita@gmail.com> <1565888399-21550-5-git-send-email-akinobu.mita@gmail.com> <20190817145509.GA18381@amd> <925633c4-a459-5e84-9c9a-502a504fdc82@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="d6Gm4EdcadzBjdND" Content-Disposition: inline In-Reply-To: <925633c4-a459-5e84-9c9a-502a504fdc82@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org --d6Gm4EdcadzBjdND Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat 2019-08-17 22:07:43, Jacek Anaszewski wrote: > On 8/17/19 4:55 PM, Pavel Machek wrote: > > On Fri 2019-08-16 01:59:58, Akinobu Mita wrote: > >> This allows LEDs to be controlled by block device activity. > >> > >> We already have ledtrig-disk (LED disk activity trigger), but the lower > >> level disk drivers need to utilize ledtrig_disk_activity() to make the > >> LED blink. > >> > >> The LED block device trigger doesn't require the lower level drivers to > >> have any instrumentation. The activity is collected by polling the disk > >> stats. > >> > >> Example: > >> > >> echo block-nvme0n1 > /sys/class/leds/diy/trigger > >=20 > > Lets use one trigger "block" and have the device as a parameter, > > please. > >=20 > > We already have 1000 cpu triggers on 1000 cpu machines, and yes, its a > > disaster we'll need to fix. Lets not repeat the same mistake here. > >=20 > > I guess it may be slightly more work. Sorry about that. >=20 > We should be able to list available block devices to set, > so the problem would be not avoided anyway. Should we? We need to list triggers, but we may not list all the devices... > And Greg already proposed > a solution for trigger file PAGE_SIZE overflow, so this should not pose > a big problem in the future once that is implemented. Which still leaves us with pretty big/ugly triggers file... and we do not have the fix in the tree yet. Best regards, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --d6Gm4EdcadzBjdND Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl1atHIACgkQMOfwapXb+vJUHgCgkeT3UaFwfpz7+MSgycx3Oc4s Oc8An3rmb4OVTm//ScEzJqndWpDtv96c =dfr0 -----END PGP SIGNATURE----- --d6Gm4EdcadzBjdND--