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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 77301C433E0 for ; Tue, 16 Feb 2021 16:48:47 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 39C9964E10 for ; Tue, 16 Feb 2021 16:48:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 39C9964E10 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 11FD3100EB348; Tue, 16 Feb 2021 08:48:47 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2a00:1450:4864:20::62b; helo=mail-ej1-x62b.google.com; envelope-from=dan.j.williams@intel.com; receiver= Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 7A400100EB345 for ; Tue, 16 Feb 2021 08:48:44 -0800 (PST) Received: by mail-ej1-x62b.google.com with SMTP id y26so17540096eju.13 for ; Tue, 16 Feb 2021 08:48:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+ecI3AnraXxD8s3/KbtK83ACA5HZ+x4/w5NBzKVHXCM=; b=Wm4E81qbjZm4Ote4+krHtLMT/Sg47muTNtm9HAKUxuG6Ynbpz/zx9MMwTAxRVTsgVJ /dzzWYIWuocSvGpYzRWHIensXSKdcLuR4nL7RXCE+p8DgFHIcvSeX0wcN5u7/JmCK0qp acnyO5VrRzp2jteOXYfH01EwKQRMekKGfugDte/4je+KFj4VmoylnLVz45G4U+t/SrpB iZWqFLwHhLLKfGymiYFRCCxGZPBfX3wrdFNwaXAyieuKeokwaE98+EHOUIK5WC+f3xUs 9De32myHYjeq1IRoGAK7DkzalOxPCkwfTVMLHCtzioAjkOxq3Tp1syboSAYFWZtlM49Y /hvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+ecI3AnraXxD8s3/KbtK83ACA5HZ+x4/w5NBzKVHXCM=; b=S44yT/6LfEJMQLb8xypiEpuPOG85FU0Hp95UZlJG/oUHOvPJDiwxGuO1tFauY5xCk0 E9hkNA1STFBSnvshCg6kC8XpmSj2PIUl3P7K/Slw9VNIsQRiwoQASIFXJ4axfo9sgXkU iVvU6ehlO0DmykMNJK4PMmsiU3ayyuk0l7jU3NmBopHKifde3E0Q2D+CPKs4Ehzh72Ij tDNKsWv+TIiqq0R8l2hNAIU5kXKLqF4ASCxXtDuxOSWnZOE2KFIcBaUWopuMXOk/JDkL acBr85p35Xo4FZNCBu5bzcgODNORL/AU4Ro2kStO+KLL4xUDNuNFYKQRjW4grnXwHoI5 9BsQ== X-Gm-Message-State: AOAM533/LrPdeR/rEQwfGsW7qLNaG6cGlQDFweQJgAsc2r9q+8hIAjDT rOqsHFlnDJ8kS2sbAFsj55+lNJEmhTprAS7c8VGcLw== X-Google-Smtp-Source: ABdhPJw7/a6RtFAeh/ix7sMWO3UbzMvUPTqfzkV9KVjhDzFN7lG80bkPRoVGizFBbZxeH5ml2XKSfBwSVxENdDqxJEM= X-Received: by 2002:a17:906:5655:: with SMTP id v21mr3112272ejr.264.1613494122365; Tue, 16 Feb 2021 08:48:42 -0800 (PST) MIME-Version: 1.0 References: <20210216014538.268106-1-ben.widawsky@intel.com> <20210216014538.268106-10-ben.widawsky@intel.com> <20210216154857.0000261d@Huawei.com> In-Reply-To: <20210216154857.0000261d@Huawei.com> From: Dan Williams Date: Tue, 16 Feb 2021 08:48:32 -0800 Message-ID: Subject: Re: [PATCH v4 9/9] cxl/mem: Add payload dumping for debug To: Jonathan Cameron Message-ID-Hash: 5V72HLYHI7FTE7IBIXBV5ZCIVPPN5CX2 X-Message-ID-Hash: 5V72HLYHI7FTE7IBIXBV5ZCIVPPN5CX2 X-MailFrom: dan.j.williams@intel.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: Ben Widawsky , linux-cxl@vger.kernel.org, Linux ACPI , Linux Kernel Mailing List , linux-nvdimm , Linux PCI , Bjorn Helgaas , Chris Browy , Christoph Hellwig , David Hildenbrand , David Rientjes , Jon Masters , Rafael Wysocki , Randy Dunlap , "John Groves (jgroves)" , "Kelley, Sean V" X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, Feb 16, 2021 at 7:50 AM Jonathan Cameron wrote: > > On Mon, 15 Feb 2021 17:45:38 -0800 > Ben Widawsky wrote: > > > It's often useful in debug scenarios to see what the hardware has dumped > > out. As it stands today, any device error will result in the payload not > > being copied out, so there is no way to triage commands which weren't > > expected to fail (and sometimes the payload may have that information). > > > > The functionality is protected by normal kernel security mechanisms as > > well as a CONFIG option in the CXL driver. > > > > This was extracted from the original version of the CXL enabling patch > > series. > > > > Signed-off-by: Ben Widawsky > > My gut feeling here is use a tracepoint rather than spamming the kernel > log. Alternatively just don't bother merging this patch - it's on the list > now anyway so trivial for anyone doing such debug to pick it up. > I've long wanted to make dev_dbg() a way to declare trace-points. With that, enabling it as a log message, or a trace-point is user policy. The value of this is having it readily available, not digging up a patch off the list for a debug session. _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org 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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 0B3EBC433E6 for ; Tue, 16 Feb 2021 16:49:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5D6364E09 for ; Tue, 16 Feb 2021 16:49:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230166AbhBPQt0 (ORCPT ); Tue, 16 Feb 2021 11:49:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230006AbhBPQtZ (ORCPT ); Tue, 16 Feb 2021 11:49:25 -0500 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35D51C061756 for ; Tue, 16 Feb 2021 08:48:45 -0800 (PST) Received: by mail-ej1-x62c.google.com with SMTP id lu16so2771973ejb.9 for ; Tue, 16 Feb 2021 08:48:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+ecI3AnraXxD8s3/KbtK83ACA5HZ+x4/w5NBzKVHXCM=; b=Wm4E81qbjZm4Ote4+krHtLMT/Sg47muTNtm9HAKUxuG6Ynbpz/zx9MMwTAxRVTsgVJ /dzzWYIWuocSvGpYzRWHIensXSKdcLuR4nL7RXCE+p8DgFHIcvSeX0wcN5u7/JmCK0qp acnyO5VrRzp2jteOXYfH01EwKQRMekKGfugDte/4je+KFj4VmoylnLVz45G4U+t/SrpB iZWqFLwHhLLKfGymiYFRCCxGZPBfX3wrdFNwaXAyieuKeokwaE98+EHOUIK5WC+f3xUs 9De32myHYjeq1IRoGAK7DkzalOxPCkwfTVMLHCtzioAjkOxq3Tp1syboSAYFWZtlM49Y /hvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+ecI3AnraXxD8s3/KbtK83ACA5HZ+x4/w5NBzKVHXCM=; b=Uw0QBr6/c17wZ/HQcaoUKZSY6oAt+8XD8kNn3EEWjv7WjIkXGIPf3s7iyoJ82hj2Nq fB3oMZJNT1hdVGXUT1rYfM+Xe+RObp85FZ9+w9IS2tzULe0LhGkrEVUubGwHYtMoCgpg IBou4nZm3XQOUwWs6VHRdq80PHvKctC/NECuFE8jQNfr/gaSF1Jq2gbG+BwR4GhEwylp leuTsloSZsKnl+VXkIqlGS6fisnPoV862zSZN/PrEJi6Qw/VhTbVReI+cHgqZuhfxSnu BFcMJ4xG+O50cTWW7DeTf4G6eb7+TYrBCWsyU5y4xdCVftHgAGhIkJcBOxgCUnguu5ip d2Ew== X-Gm-Message-State: AOAM532NKM6lyU/EjK47NNNFt7Ie8hUn0D38sP657mwfmU8aTJJw27Qj QPo7aQR+PkT2CG35tSbQKyHXPB3bbCRrnl31kLLo52LeQA8= X-Google-Smtp-Source: ABdhPJw7/a6RtFAeh/ix7sMWO3UbzMvUPTqfzkV9KVjhDzFN7lG80bkPRoVGizFBbZxeH5ml2XKSfBwSVxENdDqxJEM= X-Received: by 2002:a17:906:5655:: with SMTP id v21mr3112272ejr.264.1613494122365; Tue, 16 Feb 2021 08:48:42 -0800 (PST) MIME-Version: 1.0 References: <20210216014538.268106-1-ben.widawsky@intel.com> <20210216014538.268106-10-ben.widawsky@intel.com> <20210216154857.0000261d@Huawei.com> In-Reply-To: <20210216154857.0000261d@Huawei.com> From: Dan Williams Date: Tue, 16 Feb 2021 08:48:32 -0800 Message-ID: Subject: Re: [PATCH v4 9/9] cxl/mem: Add payload dumping for debug To: Jonathan Cameron Cc: Ben Widawsky , linux-cxl@vger.kernel.org, Linux ACPI , Linux Kernel Mailing List , linux-nvdimm , Linux PCI , Bjorn Helgaas , Chris Browy , Christoph Hellwig , David Hildenbrand , David Rientjes , Ira Weiny , Jon Masters , Rafael Wysocki , Randy Dunlap , Vishal Verma , "John Groves (jgroves)" , "Kelley, Sean V" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Tue, Feb 16, 2021 at 7:50 AM Jonathan Cameron wrote: > > On Mon, 15 Feb 2021 17:45:38 -0800 > Ben Widawsky wrote: > > > It's often useful in debug scenarios to see what the hardware has dumped > > out. As it stands today, any device error will result in the payload not > > being copied out, so there is no way to triage commands which weren't > > expected to fail (and sometimes the payload may have that information). > > > > The functionality is protected by normal kernel security mechanisms as > > well as a CONFIG option in the CXL driver. > > > > This was extracted from the original version of the CXL enabling patch > > series. > > > > Signed-off-by: Ben Widawsky > > My gut feeling here is use a tracepoint rather than spamming the kernel > log. Alternatively just don't bother merging this patch - it's on the list > now anyway so trivial for anyone doing such debug to pick it up. > I've long wanted to make dev_dbg() a way to declare trace-points. With that, enabling it as a log message, or a trace-point is user policy. The value of this is having it readily available, not digging up a patch off the list for a debug session.