From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 D359330C618 for ; Tue, 15 Sep 2026 07:50:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789458656; cv=none; b=nqgB2loJadk1aBClIFO8WLnKgmv2MmEavF38bGZB1NWJlSUPx94Mc4ThEfBaEdRbXpBvlxAOWvCmvnxZE6DyXLA0Tq1P4I90zZUUWPSiRCpHOniTsyDIuyGQm2UhiGuXDSNidSuikpy+68cqxyEVQcNUmykgE1/k59vbk5/WXLk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789458656; c=relaxed/simple; bh=U+1lMvM7Kq/7Oc1lqazrAL/weMJVKlM7jTb492fFhpI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KJHoCzHjiqivfs/ACesJ7MWCCXNhuvo1OBaHViLqfeBp6Jn54dQcMe/lxwVvm2lZVVLbkDmZnZK33bp/zoUnESWNq/lfWv42KKol2/JxfEy3ldGnQUvx3I2SAq4kpV0FrvkFYeCx3egzktqqt6eeIJv2KkkEtLdiO+IoDFR9gDM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lgHiq6iJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lgHiq6iJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCA7E1F000FF; Tue, 15 Sep 2026 07:50:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789458655; bh=xOZZTAMqyxT0SJ9hM2Vwc5oJ2q8QNjstQzoWrhFGVXw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=lgHiq6iJBBcBBN4TCTKx9M/ztzio1omV9XLe1ZazKh2UdpDlXmpodJTM2fbZOoOzk iF0bmRwQtRhRtSCG2klQL9meoGD3bAJ4o+xYALJEKPJ+2tbV6yf45iBMgtUqbgmzoH a+36ZOanL2eKBI/35u1fS36sv6U7uC1KimU+2N48sBlIUxLpsFrxqglNp8kdGRRoxj 0tDVP3xa2mpA2hOPwyLZNLb+ezp9951Nt+g6+8Hduee3BgjsfzsY4hsgSLwIXhsTUV CeprwFXd0wXh0E8J0OOFWdB8eFwdMW5mUaRoYOHVpGFUbvyLtUkkqbkHtX1UlPxhbd 8j5rrY4K4PMGA== Date: Tue, 15 Sep 2026 07:50:51 +0000 From: Tzung-Bi Shih To: Petr Mladek Cc: Kees Cook , Greg Kroah-Hartman , Tony Luck , "Guilherme G. Piccoli" , Steven Rostedt , John Ogness , Sergey Senozhatsky , tfiga@chromium.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] printk: Introduce loglevel bypass for pstore console Message-ID: References: <20260831070346.3490745-1-tzungbi@kernel.org> 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=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Sep 09, 2026 at 11:28:33AM +0200, Petr Mladek wrote: > On Mon 2026-08-31 07:03:44, Tzung-Bi Shih wrote: > > Currently, offline consoles (e.g., pstore_console backed by ramoops) > > inherit the system's global console_loglevel. > > > > In production environments, physical serial consoles (UARTs) are often > > heavily rate-limited to prevent verbose messages from causing severe > > execution bottlenecks. Unfortunately, this identically silences the > > pstore console. When a kernel panic or lockup occurs, engineers are > > left inspecting a crash dump that has been stripped of the verbose logs > > that could have identified the root cause. > > > > This series introduces CON_BYPASS_LOGLEVEL, a simple flag that allows > > specialized offline consoles to request unsuppressed logs directly. > > > > Patch 1 introduces the CON_BYPASS_LOGLEVEL flag. > > Patch 2 adopts the flag in pstore_console. > > I believe that a better solution for this problem would be adding > the per-console loglevel feature, see > https://lore.kernel.org/all/cover.1764272407.git.chris@chrisdown.name/ > > It is currently blocked by a cleanup of the console registration code, > see https://lore.kernel.org/all/20260604101459.393162-1-pmladek@suse.com/ > > I am going to send v5 of the console registration code cleanup soon, > hopefully later this week or the following week. It would be nice > when it gets some more review. Thanks for the context. I completely agree that the per-console loglevel is the proper long-term solution, and I understand that console registration cleanup and the larger printk reworks are massive and complex efforts. Because those foundational changes naturally take time, I was wondering if we could consider my approach as a narrow and localized exception just for offline consoles like pstore. Given that we already use LOG_FORCE_CON to bypass loglevels on a per-message basis, introducing a symmetric per-console flag like CON_BYPASS_LOGLEVEL might be an acceptable short-term solution. Would you be open to a localized flag like this in the interim, or do you strongly prefer to hold off until the full per-console loglevel architecture lands?