From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3914DC8C7 for ; Mon, 22 Jul 2024 14:47:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721659639; cv=none; b=cHGbe0tG6GaBSIsl5vUvRf9iK2hAHXOj26qS7WaIpmbaHsFQgAtIbn+376GxL9bATGU/P5qOt6YMks0tHzCzDrg1ihXAcB0TRNspTqGIAskX76AdQRXB1JRaq6V9T4wgx6auZbwvzH03hS/+/yDzA2zK4A/gK++Dxi2dsoyAekk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721659639; c=relaxed/simple; bh=OUMNNCR39NfCOHTmzz2B3xu9QZ2bD3hDkBbPR+hwUSE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ExxZgqxK8rQ6wuxtb+D5CqQvLY+sJowsHimgjHQCCJXzCS1BSuMnVrttUFCnlkpwVsrry3xkdeDAqPk2qdrFHx3xaRW5pj6LMqCMgc8XNqC3LLxkTRGD1Z6W9c92qnt/fA+5MfJvMR5uCI5co6e8FRvzYWmQfrutgOBoBp05Iq0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=XOYweopR; arc=none smtp.client-ip=209.85.218.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="XOYweopR" Received: by mail-ej1-f53.google.com with SMTP id a640c23a62f3a-a7a843bef98so31686466b.2 for ; Mon, 22 Jul 2024 07:47:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1721659635; x=1722264435; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=gfDTHBCuRohEK0ncm3xzBbUnv8j4LdhEVL2pu4g/bkQ=; b=XOYweopRECfWN7exCnq9GDUKjut7L6w/6TJBx46y9VJcz3XYr8xExd1NBxef8jV5IG 2jx3JzdDrse3fDitWCcZSb3XSI7fiZhQ/8vOdjy37H8rVQ3gwnRDL0L2CARxvOrKGSs7 9OpTzTTi9a0aSq4f1oKFerV637WHYI68UzkSBaOB4lXlQMmI6jJUB5UWB9dnHb+j/7N/ aEIF0Zb5pXbcqc/AHC8QFFfd2C60YCMPr8SBabpgZRFoChQLJa5bkxql9H4uWuLDmkXP U6tyF1iqlNS+nzAJeLpIyE/kuJx/9EdcFGVN2X4e4werBwubqIQPEzdOhozNXsmlrMYd ROoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721659635; x=1722264435; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=gfDTHBCuRohEK0ncm3xzBbUnv8j4LdhEVL2pu4g/bkQ=; b=qi3Q7sRnz9DeAypRf2+eiyPv1EFVUJgcRXvdyLahPHox8TM3bJ/jMpWwsyjk1xE/Fo JRlddEMXiCUOOfdqsuV0UZMMoD/C+FvPbrGw/Cx8KH9e9FWMdbEt8wvNcLu5SE4+eSQE 9G/Ril3qitBtfg6oKn4uEQ6vbrAYxq/iUwZwdaeY5Ex5C+csYdpxsT8joeP/8bG+FxQY PAjjqLkITl3+hEShOZgBtgOxo4nxbBScby+UjoXhOiJZeaOkNFtPmUgJDWyTSrDPWE0J C1OirD8rDOnr3MpDDev0SEsKmMF4MdZNSvTWatkxi5m9NDzfMBt/rYiuic43T3VmYpHH JQ4g== X-Forwarded-Encrypted: i=1; AJvYcCVGAj9qey021LR110b/CbyiTD/NFzOnqT9AjgCzTpEehWgthdsXnuYZ+d8aB1xG3Mi0hu0iPgnqLDgxAZkml9LEl7MSsThNif5issJ2 X-Gm-Message-State: AOJu0YwEXbHY2SMiGYm2jBZRk1I/e/CL983PhMnbXkOielq/7TvkHNBW VZ13lbcRTkNorlj9pGKLhJ9j2lnj7Vp3EJsWkQEjckwZtJalMgzKg0GMpfThLg4= X-Google-Smtp-Source: AGHT+IE/V1ysK9/7OluPGIkN0XxqlvLcHiyifibp3AqEmHQQVIDrvMt+Q9jhUgW5HQKnT40KciPX5w== X-Received: by 2002:a17:907:7209:b0:a75:3627:fccc with SMTP id a640c23a62f3a-a7a4c446614mr523305966b.51.1721659635495; Mon, 22 Jul 2024 07:47:15 -0700 (PDT) Received: from pathway.suse.cz ([176.114.240.50]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7a3c922cb5sm431561366b.162.2024.07.22.07.47.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jul 2024 07:47:15 -0700 (PDT) Date: Mon, 22 Jul 2024 16:47:13 +0200 From: Petr Mladek To: John Ogness Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Juri Lelli Subject: Re: [PATCH printk 0/1] alternate fix for nbcon_cpu_emergency_flush() Message-ID: References: <20240719134818.3311665-1-john.ogness@linutronix.de> 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: <20240719134818.3311665-1-john.ogness@linutronix.de> On Fri 2024-07-19 15:54:17, John Ogness wrote: > Hi Petr, > > Currently in linux-next we have commit b955f0eead54 ("printk: nbcon: > Fix nbcon_cpu_emergency_flush() when preemptible"). But as you > pointed out [0], there is no need to disable preemption at all if > we only need to know if the current CPU is in emergency state. > > Here is an alternative patch that correctly addresses the issue by > avoiding the migration checks. > > Since the previous patch is not yet mainline, perhaps you want to > use this one instead in order to avoid a revert. Up to you. Makes sense. I have replaced the commit b955f0eead54 ("printk: nbcon: Fix nbcon_cpu_emergency_flush() when preemptible") with this new patch in printk/linux.git, branch rework/write-atomic. > [0] https://lore.kernel.org/lkml/Zn7b8g1HtuTIAwyi@pathway.suse.cz > > John Ogness (1): > printk: nbcon: do not require migration disabled for > nbcon_get_cpu_emergency_nesting() > > kernel/printk/nbcon.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) Best Regards, Petr