From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f175.google.com (mail-qk1-f175.google.com [209.85.222.175]) (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 9340B2836A6 for ; Tue, 6 May 2025 17:29:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746552585; cv=none; b=dodaeEoDFwrFqtvVVGRaV2L4tkcXrm3fj7X6dAxVrnrImzd6wJKxsUii8z9ugyiUoPvhQyCOZfBqHktKYeqADJR0qTRIRqvNlyyN+dHi/gPRChtyT5AwYS4mWAJfbjMDB219RMjDTCzLrr2tqCpFApHjrPdh8NjwSe6LgxuSfBc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746552585; c=relaxed/simple; bh=P5P11usWkDjq0CdPX0+FsxN/e9x+8gnH+2D4IK1ObN0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WKcijxKGhgs1H+hl3of3dcX3HDnJHMNPXaS7EGOWA+Ki1IY65F9HveQ0EcVqanVwFiOppJcT5xKlc2MHjcuVVq+BAIi1KhHG5EXdirmR86h2ri1Ns3FDR4LPFw9+wpw0NUASLde9MLKRPDyErchpPy9f0TlkOP+g+xWj+8Jb+qI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b=LQ4zi+Bj; arc=none smtp.client-ip=209.85.222.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="LQ4zi+Bj" Received: by mail-qk1-f175.google.com with SMTP id af79cd13be357-7c5e39d1e0eso649494085a.1 for ; Tue, 06 May 2025 10:29:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1746552582; x=1747157382; 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=OaMyDCrAoG//6LMBGGysI9lA09I32hvxiR+VhJh6OEo=; b=LQ4zi+BjTVywfI5t+zUIG0xEqebQNrD+v78GSMWl8BA4Z+fWIl4mnqf9/kdueqE+oD KkDqEU3CJyieWe1azVLYv6QKkXxsr0T68gaeLpoqU1Isfk/XHF2jmabHSPP8CZTS36c3 41+Ylp5ALAHFm5D5aM9FJz0GShBVjczfatWvV4ffIfpBjeayqWY7NEbEBiQOntSw0QhV 4hfoIyLZotiGktafNQm1fw2RVFvaSBbaI+lL2vNpSE/pILHxlt+aFGrCEs1f6Yiyjqui Ag7FOOXkwePX4ywpvtRiFuI1z/LgSM1P97WG+63XJALqvpwDtysdSPvIE8dx7fHk9fkt oDLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746552582; x=1747157382; 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=OaMyDCrAoG//6LMBGGysI9lA09I32hvxiR+VhJh6OEo=; b=G5mkfwsnY5Lvf/adfe1LyazppXgm2RDq2vTZeqfvrp6BifohfPav5m0XzN3QxEQTjs TrONNtPM1vjYG8L73rssl4orIdvohD7qK6PSOf7buGaIlH42UkmJe942KFuPQ9QFdYPy nLSzDvttEy6i/NQTJvvFYX6KeALAKRglNuSnNdk0q3ZudIQveQZWeGfOGpdGOGyej092 6pmYYHC0QmKNuk9m9TD+xcdYCi6SG+jgKgmKH7yG1mVJdiuA7iCIu7nfV1gzf7UYSnBv qwZNnv6d7ozR8rG6I52jz8tQZwEVVuWZxTvpJ0eP+lIPeON+BDCBFP/tuVMEF+tU8U1d D4Dw== X-Forwarded-Encrypted: i=1; AJvYcCV5fJXjbP3QQ9A9F6OUIcfE4pfO5oLPfs/ngfLm5UYPRDn8fYB31kEdHuW4uX+Ah0dtEl8Cdq8cLJatEDk=@vger.kernel.org X-Gm-Message-State: AOJu0Yx1eXv9+8ZIlStfkKYhSOiOQmiRH10u/4ZSRmiuDSuuJCd1HFUs URXxYiHefTPEXozJW32y9Dx+fn0wFWcnW38N7lysLI7TNm2lcpRQxnvqU0JqKFo= X-Gm-Gg: ASbGnct346IQ53kB5G/H9UrrBVrMrBPdmECNnRZriMDrW48gDwc+j5sK1/yKSjfczXS E8WtOZiSJH5Czlxtn6opJFJXOz3FlQ40745llHBi2jkCaSzs/Tlw8zfcQUQTeDIJuol75xzQs// t802dWbWMFGRClS28H4yJFlfbsoWsEaPs9IBfvfjLrTjPr0GnbbWBsEH5KT0taJLKLbaKZTrj07 +cDKBl5ygNmgVOD+7YnZMP3pjy32OPD0A6ZKcedYli4ubUSO1mjTtC1oa7C6LPCz35CImCoATaf QbsqKMzrTujCZBUMiBIEPcN8JAyPzpOx8jyFnaz9/hTjzWC4RzQ6YYLD8t6pCCsPD9wyzaO645G HGI3O3O0F5zTqmYKYaXw= X-Google-Smtp-Source: AGHT+IFMZ5fIINTPeKhkWdgeEHlC4vrkCQlZ8NYfWErLZxx+U/X8plflWy2yROICiyb87lWzQQaofQ== X-Received: by 2002:a05:620a:46aa:b0:7ca:e989:23fd with SMTP id af79cd13be357-7caf73a1866mr28024085a.24.1746552582447; Tue, 06 May 2025 10:29:42 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-167-219-86.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.167.219.86]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7caf75b5334sm3266885a.80.2025.05.06.10.29.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 May 2025 10:29:42 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1uCM6v-00000000LGb-2K8I; Tue, 06 May 2025 14:29:41 -0300 Date: Tue, 6 May 2025 14:29:41 -0300 From: Jason Gunthorpe To: Lu Baolu Cc: Joerg Roedel , Will Deacon , Robin Murphy , Kevin Tian , iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/2] iommu/vt-d: Replace spin_lock with mutex to protect domain ida Message-ID: <20250506172941.GB33739@ziepe.ca> References: <20250430021135.2370244-1-baolu.lu@linux.intel.com> <20250430021135.2370244-3-baolu.lu@linux.intel.com> 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: <20250430021135.2370244-3-baolu.lu@linux.intel.com> On Wed, Apr 30, 2025 at 10:11:35AM +0800, Lu Baolu wrote: > The domain ID allocator is currently protected by a spin_lock. However, > ida_alloc_range can potentially block if it needs to allocate memory to > grow its internal structures. > > Replace the spin_lock with a mutex which allows sleep on block. Thus, > the memory allocation flags can be updated from GFP_ATOMIC to GFP_KERNEL > to allow blocking memory allocations if necessary. > > Introduce a new mutex, did_lock, specifically for protecting the domain > ida. The existing spinlock will remain for protecting other intel_iommu > fields. > > Signed-off-by: Lu Baolu > Reviewed-by: Kevin Tian > --- > drivers/iommu/intel/dmar.c | 1 + > drivers/iommu/intel/iommu.c | 12 ++++-------- > drivers/iommu/intel/iommu.h | 2 ++ > 3 files changed, 7 insertions(+), 8 deletions(-) Reviewed-by: Jason Gunthorpe Jason