From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.160.177 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792699952; b=lSPly7QJzraUMmsBmrDlFpYPNqZR9SlmrulS3vUMXSpJ27sS2V/4j49rO7fBbrrZfhsV J1mmtV7Mo+7JbJIJe+iaq94uQtnx2D+sb1ha4EkbqcJWhFeDUTOR/sFeDO+1HyaotNd82 azbMJ+CxH6fiSkfwJuiKT7MXOQi8tsDNo2DyHkqTMOyoZ75eIM5CRYknw4vKvcLKbb7pF NHw3Mfj432gfx5trq5YMbeFw5q8KEzMG2aS+GB3yKaZ1eEDxtEfpSagBR0ci4/YcIGv7c wA8gLQsIOBJ96sdBPNQhFD1LaTec+quhpTN5SF5L9YglzH10jLOvyz/1fYAHKGjDFwg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792699952; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: Received:Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; bh=I8JrjL/Toni0rgHeKLxMi210agLPfR373jhOEmm9NDM=; b=f7Q1EdL77dUMppNbtejaYA+eEcnlYr/rAJTtsSV9NL96SiiTR8O1OvF/zqBpcz2oRDuu SGFTXxAjkXZXlrZPRoloUZYN+TaFf4ZlgPV76/UkuOl/+ooIu01t83PvneizdfXWsH9zs 9wU/DSMIEsc2p5Zjl9DsWZTCy5lnq+hOg2BBAQDqKVh2sNJzPTPcAmuePuVoa8otx/IyX MZ/oFz3QAX3Gx3zyURPSG9d47xd7iiyU2UjvkrLbCR46fzBEYcwpOsMyNggr5s4WWbbvz d7USuRbIXTc3z0wq01rdsCdwNpBHh5A2TemyjnPprM1DcbMEnf+pEoOJzmgq3OriKHQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256 header.s=google header.b=bEf24BE7; arc=none smtp.remote-ip=209.85.160.177 Received: from mail-qt1-f177.google.com (mail-qt1-f177.google.com [209.85.160.177]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7EA68606A319 for ; Thu, 22 Oct 2026 20:12:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 7EA68606A319 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, unprotected) header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256 header.s=google header.b=bEf24BE7 Received: by mail-qt1-f177.google.com with SMTP id d75a77b69052e-5361e313e63so1136031cf.3 for ; Thu, 22 Oct 2026 13:12:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1792699950; x=1793304750; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=I8JrjL/Toni0rgHeKLxMi210agLPfR373jhOEmm9NDM=; b=bEf24BE77jeSVrye/0K8bqAhBtq3l4ipVokvy1WTo9I171dh1cPnLebWZP98ZbHc1p AY82b/V/Z8Ber8ZWp8VUWvVQdVKVcws1+qTT8I1nIkiiUcBGdUJt2If+NgtXZWXT8aBs uKfYqDijGgrn/rN6GkRbg/nS7tyReOXZC1wz27PGG3UX69KRZ1voQbKcO/EJ7VCH+ev3 9w3+gkzOCiUWskxpeRuVsDRp3YDSWCkTFq4QinNxLt/YPbd0DW10RzKL39WEfK6b51Xg gE0pjKAlKmDwW9sqvGKBvCi87C9mbwgaQyyqQUYs4WaTKD+zF6NXq0IhdXGPVmv9ZqYX i7oA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792699950; x=1793304750; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=I8JrjL/Toni0rgHeKLxMi210agLPfR373jhOEmm9NDM=; b=F/zqHAIo+bMgKxlUYQkSi73rsVTPN60ePIIOgp2WXTK2NwG+5zEIcjXv7o36Ihky04 +zsBhxtRDxHKjbtf8933AadlCiKYjz5E6Y/VpUSEZZTxP1fzQqDq4J3tEv8P/hvc1G6g pQS+vcUfAsKFsx4MuoINbfLRxUReh2qkZ+8ci06XsPECMwjsYCHnpdScj6QiHuyWIhnz wnblhCaInYjbadY9RaGbWGKYTwynDhvGMncwlVhybqlxzYcOgVDMTwcDR+8h/E0C6PjC k0hZTIt3d57Zg9ZTAZU8k5dI5du65YMbKf7m76z8jVx+hH7zsnGT1lblWONAJ8w6vO9C kiUA== X-Forwarded-Encrypted: i=1; AKwUvBzK8O2FjuDmhfEYGsz0fi4vvOsG7UHiT46sb1qYOAYWtQTHMBU8ibhK8XaLNJ67Dwg3cwMYtqTfpvQ=@vger.kernel.org X-Gm-Message-State: AFq9FYK1aIW6fkcjo4ElgIbv+Iwpf9fNr3j+MhWyny7/Iv+VZqxKuc/E tdK+Dbre0m7WWl2E1TuHdF34M37w+uFry1wF17KuNtPfaPAMMEtoRWl3JYjYPmnpneY= X-Gm-Gg: AYBFou00Bcl2qHVv7OsKnj1PyNmPCbnl8jvfypgD2uYHVlAW7uz7jSxhMoI2UPLhRJg S85HrGgW1Tx5fsnBl9/4Iqt9jhWYp6bs8eMHcw4t4hASgrSPPbPgljjM4bcCKcgu7zrGSSnCQ9I 5VTybPsdAMz6UXulNNrBf3dSAETBH4nNUbglIUjjyxGJkzZLcf2Oaqr5Hr1g9kr+hdKO5eupNcp 1PU89ahUKiAwvZPUBlRAO0M7rd9MuX5+92ahPgIeNJR+HtVV59j1nUSwMXDL3+TizZctcw2sWkn yGWQ5r+XQN64JQVFkLCkzZ7nLXaZDyvIVW7Vvx4+4I0mVtgIEAW3KhZOLb+AOVmN4hevJBKY7mD 4lLrgsDZP67YJS2OmZkgyUrUvltACk7UHDcCo/Sfcm94Er1c2FTfbORPHiDk+AqK6oOFd479gU+ To03KVpaE6LnThuh9V/KIgznB93ZlixyRP3HR2cu8wIstzDaoRJ6c9F5BSaTaGFyJB7vXzS4w3/ VyWTA3DygjY98ojcmrhRzWXl9ahgg1WAyNxuBCzYC2Be0zaSziW/88Y28ZveEjIEK+sfFYxxer5 zkuc2zuYxB5j2Xbn+ItgqsYJPcp+Vv7/uvuZXw== X-Received: by 2002:ac8:5a85:0:b0:536:6378:c7fe with SMTP id d75a77b69052e-5369b8204d9mr99553871cf.47.1792699950468; Thu, 22 Oct 2026 13:12:30 -0700 (PDT) Received: from ziepe.ca (hlfxns010zw-159-2-239-150.pppoe-dynamic.high-speed.ns.bellaliant.net. [159.2.239.150]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-536c14da10csm1768631cf.0.2026.10.22.13.12.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Oct 2026 13:12:29 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1xJz9J-0000000FoSN-1XEC; Thu, 22 Oct 2026 17:12:29 -0300 Date: Thu, 22 Oct 2026 17:12:29 -0300 From: Jason Gunthorpe To: Luigi Rizzo Cc: "David Hildenbrand (Arm)" , Luigi Rizzo , Joerg Roedel , Will Deacon , Robin Murphy , Christoph Hellwig , Marek Szyprowski , Andrew Morton , Vlastimil Babka , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich , Jonathan Corbet , Jesper Dangaard Brouer , Ilias Apalodimas , Willem de Bruijn , Kuniyuki Iwashima , Joshua Washington , Harshitha Ramamurthy , Saeed Mahameed , Tariq Toukan , Tony Nguyen , Przemek Kitszel , Alexander Lobakin , Michael Chan , Pavan Chebbi , iommu@lists.linux.dev, netdev@vger.kernel.org, linux-mm@kvack.org, driver-core@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC: DMA_PMD 00/22] DMA_PMD: PMD_SIZE-backed IO buffer pools Message-ID: <20261022201229.GH3381610@ziepe.ca> References: <20261003212241.3432303-1-lrizzo@google.com> <0cc1cac1-a500-489b-9c1b-b49598b5550b@kernel.org> X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sat, Oct 17, 2026 at 07:11:28PM +0200, Luigi Rizzo wrote: > > We should probably just find a way to describe that this is a POOL that focuses > > on physical contiguity in some configured granularity. > > Before embarking in a global renaming, I would like to get opinions on > acceptable alternative names (possibly with a short prefix usable for > identifiers in the code). I could think of the following > > DMA_PMAP (for PreMapped or Persistent Mapped) > or, ahemm... > DMA_PISA (Pooled IOMMU Superpage Allocator) > both using dmap_ for internal name prefixes Can someone explain what outside netdev would use this? And why you couldn't do this in the netdev page pool? It is not a common workload to have the DMA allocator be the one that allocates the memory. Usually we are DMA'ing from memory that was allocated someplace else. I think Robin is right, this is just a special case of the dma pool, and it certainly shouldn't be something as grandiose as a subsystem.. Jason