From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 D92CA31352F for ; Fri, 24 Oct 2025 11:01:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761303693; cv=none; b=eXb9lMj+doSGSd8Rwt6vj/+p8/jIhIZNqhMpKxaJoKwaPdq40vGWNuI9v71wUnWUdUVQEiyGmtEsL2Aq2QNNK7qny3cSwAu9aTdNdoL3uMYNtHooRQahiFooEhmW5FOgdfzhEC+pVZWLPOFu5wJ31oKhCKirwU5GojW7KVMV8I8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761303693; c=relaxed/simple; bh=mCAe9ncMYt9xNubzh6i4PNc5V9nSnsjSFZkvBPHzR2M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tYacUsVCsMYbxZMAzFrLLKeehx1WvJYvpdI26SthGfuOMzxgc/niIrZWPHGiG8Vnw7jgBSd0Bt0X6DFYFP0y/xPI10txXb9jxHQRi8otjNXAWG4wrCuJFnu+vkU030u0d5tZeqOtwxgIUii5H9idNoTlZawa8GPiQgom/EGkIlI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=IhkEPRBY; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IhkEPRBY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1761303690; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=mCAe9ncMYt9xNubzh6i4PNc5V9nSnsjSFZkvBPHzR2M=; b=IhkEPRBYfkwJkZFlSsMxvEySeuNaoNFNJVUiJbc04myswbIFkyQ2Cigosb7yu+c1+O1oCN eORufb4gxrP0dni8Dka3CW2sWenmFMUp3J7jT9Gvzv2tKPmyHb+nC480/5CAipdMATH767 gzWz3Xg0Lz0OFnIitJWaubxHJY7b5m0= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-527-n6R1ZRgFOhCL1_-48qj73g-1; Fri, 24 Oct 2025 07:01:27 -0400 X-MC-Unique: n6R1ZRgFOhCL1_-48qj73g-1 X-Mimecast-MFC-AGG-ID: n6R1ZRgFOhCL1_-48qj73g_1761303686 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3169618001D1; Fri, 24 Oct 2025 11:01:26 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.19]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 5715D180057D; Fri, 24 Oct 2025 11:01:24 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 24 Oct 2025 13:00:07 +0200 (CEST) Date: Fri, 24 Oct 2025 13:00:04 +0200 From: Oleg Nesterov To: Sebastian Andrzej Siewior Cc: Petr Mladek , John Ogness , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] printk_legacy_map: use LD_WAIT_CONFIG instead of LD_WAIT_SLEEP Message-ID: <20251024110004.GF771@redhat.com> References: <20251022154115.GA22400@redhat.com> <20251023103234.GA27415@redhat.com> <20251023142655.FvZkeSa-@linutronix.de> <20251024104055.GE771@redhat.com> <20251024105222.RZPI5xWT@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: <20251024105222.RZPI5xWT@linutronix.de> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 10/24, Sebastian Andrzej Siewior wrote: > > On 2025-10-24 12:40:56 [+0200], Oleg Nesterov wrote: > > On 10/23, Sebastian Andrzej Siewior wrote: > > > > > > On 2025-10-23 12:32:34 [+0200], Oleg Nesterov wrote: > > > > printk_legacy_map is used on !PREEMPT_RT to avoid false positives from > > > > CONFIG_PROVE_RAW_LOCK_NESTING about raw_spinlock/spinlock nesting. > > > > > > Could we please get rid of CONFIG_PROVE_RAW_LOCK_NESTING here? This is > > > lockdep internal implementation and has nothing to do with printk or > > > anything. > > > > OK, but let me ensure I didn't miss something (again ;). > > > > I mentioned CONFIG_PROVE_RAW_LOCK_NESTING in the changelog because if > > CONFIG_PROVE_RAW_LOCK_NESTING=n, then LD_WAIT_CONFIG == LD_WAIT_SPIN > > and lockdep will not complain if spinlock_t nests inside raw_spinlock_t. > > > > IOW, without CONFIG_PROVE_RAW_LOCK_NESTING printk_legacy_map is not > > really needed. > > This is correct but CONFIG_PROVE_RAW_LOCK_NESTING is kind of a must and > should not be an option. Yes, I see your point. Just wanted to ensure I fully understand it. Thanks, Oleg.