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=-4.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 68690C4338F for ; Mon, 9 Aug 2021 19:54:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 398816101D for ; Mon, 9 Aug 2021 19:54:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229812AbhHITyu (ORCPT ); Mon, 9 Aug 2021 15:54:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229516AbhHITyt (ORCPT ); Mon, 9 Aug 2021 15:54:49 -0400 Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC479C0613D3; Mon, 9 Aug 2021 12:54:28 -0700 (PDT) Received: by mail-oi1-x234.google.com with SMTP id bi32so1407674oib.2; Mon, 09 Aug 2021 12:54:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=eF/17oHdLHVi0xJUwmBxYd83d4UXKACoh9Nvbc+lX38=; b=Qx5ivI6cU6P2mhct69DR4Od968CCXsxwhHooCmsn7ViDPJWdv9wmba5Gv9GMRa4zXq j+3HVdFPZ2DHm0LP/70RPOToE5OSiVBeeon02jnXZB0j1y+ErkmMcpVrWQkpHxI6t+J+ 8u6l8jfRNo4eJbn1iZSDIGd+5ShRt88O3SP+dqMQEe0ijMnFX/ZR4WqP+h3r13TUVFk9 hilvR8LexDb5R9Smon34lsaACVKFy7SEYMlUwrczgNv52naDtmJiOSOyCJk1wIam7WhS LPv/Uq2rWaFcuHKBSN6qIh8YpWFH71T6rVKVdxiG5yhIWJc10Yw1IwHxLBZr31r60Crk zF5Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=eF/17oHdLHVi0xJUwmBxYd83d4UXKACoh9Nvbc+lX38=; b=L26fDr1aBSXuEVlOGPobo1sl3scYUdELH1xbFHF1Q2C2mpEKQVD9J0f64fmphTjTgC N5/43wcDxQpWyyN6Ic4cDd29BRbOR9d105XqEsmdFLO5BZLJKKUqqhgVXhAOn5SdznzR S+0lxHT+YuVbNynX6Rf+l1c9+nXm0p5lxHrSBXEJ28fGwhfMoKn2rMUNX5AHZIyyrGtQ 3KNkP3Ct//MUpr2Do1/0YXe8Hl/5eBRpSlJ5jEV4zXwSYZ3z9K5EapcYr5+0I0ofosop 7JpBA7etjo+zin15ajJS3tR9NCoA18vYNEQ4ZDat/cCMv9ZQzgAMO4upDBzkGcc/ChTD A48g== X-Gm-Message-State: AOAM5319qK/Jmzp3Q5w3CHcj2BuIb4mq4OYc3uLvIWTUaxStBu3gc4Ou YwWaTzlPEODecnys4vxO38oFknstrCQlQB6Y X-Google-Smtp-Source: ABdhPJyV0R3ALmj8cS21Wn76ApwuWuRO83XWXFzpzft+z2CK5Lf2m0xrYJAy2LgcTSHv279o8yQV6w== X-Received: by 2002:aca:31d5:: with SMTP id x204mr674161oix.136.1628538868132; Mon, 09 Aug 2021 12:54:28 -0700 (PDT) Received: from ian.penurio.us ([47.184.51.90]) by smtp.gmail.com with ESMTPSA id n5sm541958oij.56.2021.08.09.12.54.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 Aug 2021 12:54:27 -0700 (PDT) Subject: Re: [RFC PATCH v2 00/10] Add configurable block device LED triggers To: =?UTF-8?Q?Marek_Beh=c3=ban?= , pali@kernel.org Cc: linux-block@vger.kernel.org, linux-leds@vger.kernel.org, axboe@kernel.dk, pavel@ucw.cz, linux-kernel@vger.kernel.org, kernelnewbies@kernelnewbies.org References: <20210809033217.1113444-1-arequipeno@gmail.com> <20210809205633.4300bbea@thinkpad> From: Ian Pilcher Message-ID: <81c128a1-c1b8-0f1e-a77b-6704bade26c0@gmail.com> Date: Mon, 9 Aug 2021 14:54:26 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210809205633.4300bbea@thinkpad> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org Marek - Thanks for taking the time to look at this. On 8/9/21 1:56 PM, Marek Behún wrote: > It may be simpler, but it is in contrast to how the netdev trigger > works, which already is in upstream for many years. I really think we > should try to have similar sysfs ABIs here. (I understand that the > netdev trigger is currently unable to handle multiple network > interfaces - but it is possible to extend it so.) I'm not unalterably opposed to the idea, but I don't currently see a way to do that without resolving block devices (struct gendisk) by name, and that seems to be a no-no. If you (or anyone else) has a suggestion on how to get around this obstacle, I'd be willing to give it a shot. > I think it is reasonable to be able to set something like this: > led0 : blink on activity on any of [sda, sdb, sdc] > led1 : blink on activity on sda > led2 : blink on activity on sdb > led3 : blink on activity on sdc > > If I am reading your code correctly, it looks that only one LED can be > configured for a block device. Is this true? If so, then the above > configuration cannot be set. You're correct that it's not possible with the current code. Multiple devices can be associated to with a single LED, but there's not currently a way to drive more than 1 LED from a single device. This is something that could be changed. > Also you are blinking the LED on any request to the block device. I > would rather expect to be able to set the LED to blink on read and on > write. (And possibly on other functions, like discard, or critical > temperature, or error, ...) I would like to know what other people > think about this. I wanted to keep things as simple as possible for now. I don't think that there's any particular reason that separated LEDs couldn't be configured for read and write requests. (It looks like it should be pretty easy to distinguish reads vs writes in a struct request.) My feeling is that things like temperature, errors, etc. are better monitored from user space, as they tend to require actively querying the drive. Like you, I'm interested in knowing if there is actually hardware out there that has separate read/write LEDs. All in all, I feel like I should be able to implement almost everything that you've suggested, *if* I can figure out the block device lookup issue, but I really don't have any ideas on that. Thanks for your patience and feedback! -- ======================================================================== In Soviet Russia, Google searches you! ======================================================================== 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=-2.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 64FE6C4338F for ; Mon, 9 Aug 2021 19:54:58 +0000 (UTC) Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0D9CC60C51 for ; 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charset="utf-8"; Format="flowed" Errors-To: kernelnewbies-bounces@kernelnewbies.org TWFyZWsgLQoKVGhhbmtzIGZvciB0YWtpbmcgdGhlIHRpbWUgdG8gbG9vayBhdCB0aGlzLgoKT24g OC85LzIxIDE6NTYgUE0sIE1hcmVrIEJlaMO6biB3cm90ZToKPiBJdCBtYXkgYmUgc2ltcGxlciwg YnV0IGl0IGlzIGluIGNvbnRyYXN0IHRvIGhvdyB0aGUgbmV0ZGV2IHRyaWdnZXIKPiB3b3Jrcywg d2hpY2ggYWxyZWFkeSBpcyBpbiB1cHN0cmVhbSBmb3IgbWFueSB5ZWFycy4gSSByZWFsbHkgdGhp bmsgd2UKPiBzaG91bGQgdHJ5IHRvIGhhdmUgc2ltaWxhciBzeXNmcyBBQklzIGhlcmUuIChJIHVu ZGVyc3RhbmQgdGhhdCB0aGUKPiBuZXRkZXYgdHJpZ2dlciBpcyBjdXJyZW50bHkgdW5hYmxlIHRv IGhhbmRsZSBtdWx0aXBsZSBuZXR3b3JrCj4gaW50ZXJmYWNlcyAtIGJ1dCBpdCBpcyBwb3NzaWJs ZSB0byBleHRlbmQgaXQgc28uKQoKSSdtIG5vdCB1bmFsdGVyYWJseSBvcHBvc2VkIHRvIHRoZSBp ZGVhLCBidXQgSSBkb24ndCBjdXJyZW50bHkgc2VlIGEgd2F5CnRvIGRvIHRoYXQgd2l0aG91dCBy ZXNvbHZpbmcgYmxvY2sgZGV2aWNlcyAoc3RydWN0IGdlbmRpc2spIGJ5IG5hbWUsIGFuZAp0aGF0 IHNlZW1zIHRvIGJlIGEgbm8tbm8uCgpJZiB5b3UgKG9yIGFueW9uZSBlbHNlKSBoYXMgYSBzdWdn ZXN0aW9uIG9uIGhvdyB0byBnZXQgYXJvdW5kIHRoaXMKb2JzdGFjbGUsIEknZCBiZSB3aWxsaW5n IHRvIGdpdmUgaXQgYSBzaG90LgoKPiBJIHRoaW5rIGl0IGlzIHJlYXNvbmFibGUgdG8gYmUgYWJs ZSB0byBzZXQgc29tZXRoaW5nIGxpa2UgdGhpczoKPiAgICBsZWQwIDogYmxpbmsgb24gYWN0aXZp dHkgb24gYW55IG9mIFtzZGEsIHNkYiwgc2RjXQo+ICAgIGxlZDEgOiBibGluayBvbiBhY3Rpdml0 eSBvbiBzZGEKPiAgICBsZWQyIDogYmxpbmsgb24gYWN0aXZpdHkgb24gc2RiCj4gICAgbGVkMyA6 IGJsaW5rIG9uIGFjdGl2aXR5IG9uIHNkYwo+IAo+IElmIEkgYW0gcmVhZGluZyB5b3VyIGNvZGUg Y29ycmVjdGx5LCBpdCBsb29rcyB0aGF0IG9ubHkgb25lIExFRCBjYW4gYmUKPiBjb25maWd1cmVk IGZvciBhIGJsb2NrIGRldmljZS4gSXMgdGhpcyB0cnVlPyBJZiBzbywgdGhlbiB0aGUgYWJvdmUK PiBjb25maWd1cmF0aW9uIGNhbm5vdCBiZSBzZXQuCgpZb3UncmUgY29ycmVjdCB0aGF0IGl0J3Mg bm90IHBvc3NpYmxlIHdpdGggdGhlIGN1cnJlbnQgY29kZS4gIE11bHRpcGxlCmRldmljZXMgY2Fu IGJlIGFzc29jaWF0ZWQgdG8gd2l0aCBhIHNpbmdsZSBMRUQsIGJ1dCB0aGVyZSdzIG5vdApjdXJy ZW50bHkgYSB3YXkgdG8gZHJpdmUgbW9yZSB0aGFuIDEgTEVEIGZyb20gYSBzaW5nbGUgZGV2aWNl LiAgVGhpcwppcyBzb21ldGhpbmcgdGhhdCBjb3VsZCBiZSBjaGFuZ2VkLgoKPiBBbHNvIHlvdSBh cmUgYmxpbmtpbmcgdGhlIExFRCBvbiBhbnkgcmVxdWVzdCB0byB0aGUgYmxvY2sgZGV2aWNlLiBJ Cj4gd291bGQgcmF0aGVyIGV4cGVjdCB0byBiZSBhYmxlIHRvIHNldCB0aGUgTEVEIHRvIGJsaW5r IG9uIHJlYWQgYW5kIG9uCj4gd3JpdGUuIChBbmQgcG9zc2libHkgb24gb3RoZXIgZnVuY3Rpb25z LCBsaWtlIGRpc2NhcmQsIG9yIGNyaXRpY2FsCj4gdGVtcGVyYXR1cmUsIG9yIGVycm9yLCAuLi4p IEkgd291bGQgbGlrZSB0byBrbm93IHdoYXQgb3RoZXIgcGVvcGxlCj4gdGhpbmsgYWJvdXQgdGhp cy4KCkkgd2FudGVkIHRvIGtlZXAgdGhpbmdzIGFzIHNpbXBsZSBhcyBwb3NzaWJsZSBmb3Igbm93 LiAgSSBkb24ndCB0aGluawp0aGF0IHRoZXJlJ3MgYW55IHBhcnRpY3VsYXIgcmVhc29uIHRoYXQg c2VwYXJhdGVkIExFRHMgY291bGRuJ3QgYmUKY29uZmlndXJlZCBmb3IgcmVhZCBhbmQgd3JpdGUg cmVxdWVzdHMuICAoSXQgbG9va3MgbGlrZSBpdCBzaG91bGQgYmUKcHJldHR5IGVhc3kgdG8gZGlz dGluZ3Vpc2ggcmVhZHMgdnMgd3JpdGVzIGluIGEgc3RydWN0IHJlcXVlc3QuKQoKTXkgZmVlbGlu ZyBpcyB0aGF0IHRoaW5ncyBsaWtlIHRlbXBlcmF0dXJlLCBlcnJvcnMsIGV0Yy4gYXJlIGJldHRl cgptb25pdG9yZWQgZnJvbSB1c2VyIHNwYWNlLCBhcyB0aGV5IHRlbmQgdG8gcmVxdWlyZSBhY3Rp dmVseSBxdWVyeWluZwp0aGUgZHJpdmUuCgpMaWtlIHlvdSwgSSdtIGludGVyZXN0ZWQgaW4ga25v d2luZyBpZiB0aGVyZSBpcyBhY3R1YWxseSBoYXJkd2FyZSBvdXQKdGhlcmUgdGhhdCBoYXMgc2Vw YXJhdGUgcmVhZC93cml0ZSBMRURzLgoKQWxsIGluIGFsbCwgSSBmZWVsIGxpa2UgSSBzaG91bGQg YmUgYWJsZSB0byBpbXBsZW1lbnQgYWxtb3N0IGV2ZXJ5dGhpbmcKdGhhdCB5b3UndmUgc3VnZ2Vz dGVkLCAqaWYqIEkgY2FuIGZpZ3VyZSBvdXQgdGhlIGJsb2NrIGRldmljZSBsb29rdXAKaXNzdWUs IGJ1dCBJIHJlYWxseSBkb24ndCBoYXZlIGFueSBpZGVhcyBvbiB0aGF0LgoKVGhhbmtzIGZvciB5 b3VyIHBhdGllbmNlIGFuZCBmZWVkYmFjayEKCi0tIAo9PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KICAgICAgICAg ICAgICAgICAgSW4gU292aWV0IFJ1c3NpYSwgR29vZ2xlIHNlYXJjaGVzIHlvdSEKPT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09CgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpL ZXJuZWxuZXdiaWVzIG1haWxpbmcgbGlzdApLZXJuZWxuZXdiaWVzQGtlcm5lbG5ld2JpZXMub3Jn Cmh0dHBzOi8vbGlzdHMua2VybmVsbmV3Ymllcy5vcmcvbWFpbG1hbi9saXN0aW5mby9rZXJuZWxu ZXdiaWVzCg==