From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91D9EC433DF for ; Thu, 6 Aug 2020 17:23:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED4F22311C for ; Thu, 6 Aug 2020 17:23:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730224AbgHFRXt (ORCPT ); Thu, 6 Aug 2020 13:23:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:44438 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730027AbgHFRXn (ORCPT ); Thu, 6 Aug 2020 13:23:43 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9A7B6AED2; Thu, 6 Aug 2020 11:50:49 +0000 (UTC) Message-ID: <3a530804ad5aa96d2502da8ee3e8650b0b477c0f.camel@suse.de> Subject: Re: [PATCH v2 2/2] dma-pool: Only allocate from CMA when in same memory zone From: Nicolas Saenz Julienne To: Christoph Hellwig Cc: amit.pundir@linaro.org, linux-kernel@vger.kernel.org, Marek Szyprowski , Robin Murphy , rientjes@google.com, jeremy.linton@arm.com, linux-rpi-kernel@lists.infradead.org, iommu@lists.linux-foundation.org Date: Thu, 06 Aug 2020 13:50:29 +0200 In-Reply-To: <20200806051814.GA10143@lst.de> References: <20200803160956.19235-1-nsaenzjulienne@suse.de> <20200803160956.19235-3-nsaenzjulienne@suse.de> <20200804060633.GA7368@lst.de> <20200806051814.GA10143@lst.de> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-BLB/tUqhN7FZgmlmL87f" User-Agent: Evolution 3.36.4 MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-BLB/tUqhN7FZgmlmL87f Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2020-08-06 at 07:18 +0200, Christoph Hellwig wrote: > On Tue, Aug 04, 2020 at 11:43:15AM +0200, Nicolas Saenz Julienne wrote: > > > Second I don't see the need (and actually some harm) in preventing GF= P_KERNEL > > > allocations from dipping into lower CMA areas - something that we did= support > > > before 5.8 with the single pool. > >=20 > > My thinking is the least we pressure CMA the better, it's generally sca= rse, and > > it'll not grow as the atomic pools grow. As far as harm is concerned, w= e now > > check addresses for correctness, so we shouldn't run into problems. > >=20 > > There is a potential case for architectures defining a default CMA but = not > > defining DMA zones where this could be problematic. But isn't that just= plain > > abusing CMA? If you need low memory allocations, you should be defining= DMA > > zones. >=20 > The latter is pretty much what I expect, as we only support the default a= nd > per-device DMA CMAs. Fair enough, should I send a v3 with everything cleaned-up/rebased, or you'= d rather pick it up from your version? --=-BLB/tUqhN7FZgmlmL87f Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAl8r7oUACgkQlfZmHno8 x/6NNAf8CT1UiVU7PCKz2LUHhepxWBfqr/Fz15NMCjlWxLecIvE8NeFQYjnkzCr8 WNIEZM0Vi5yiy2M5Au0e18rt/S/U2O4wCD95KXIAO7b7iMhP0jJFh9nqnj6IDUrJ +QzQLSMHGGD+UO4bxtpONvZ0/UekL1werA7sP2qQynpUDFijzq8HZ9/U2tD+Mtyl CFUOvAI5xO6AsVH4xryG4jWUb66/hflTOJ2nwz6ybrN/R+L2UvxYrynf2/lHIZq/ wqfGMD/Oh+KAiecex8ZgavWC/Adft7bAfJ3E7JZp5V3C+wW/QB7XWeGtAAawy1nC B5Pd5WHQFwp5oP5bPzDO17kycEbD8Q== =DGkG -----END PGP SIGNATURE----- --=-BLB/tUqhN7FZgmlmL87f-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDE74C433E0 for ; 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Thu, 6 Aug 2020 11:50:49 +0000 (UTC) Message-ID: <3a530804ad5aa96d2502da8ee3e8650b0b477c0f.camel@suse.de> Subject: Re: [PATCH v2 2/2] dma-pool: Only allocate from CMA when in same memory zone From: Nicolas Saenz Julienne To: Christoph Hellwig Date: Thu, 06 Aug 2020 13:50:29 +0200 In-Reply-To: <20200806051814.GA10143@lst.de> References: <20200803160956.19235-1-nsaenzjulienne@suse.de> <20200803160956.19235-3-nsaenzjulienne@suse.de> <20200804060633.GA7368@lst.de> <20200806051814.GA10143@lst.de> User-Agent: Evolution 3.36.4 MIME-Version: 1.0 Cc: amit.pundir@linaro.org, linux-kernel@vger.kernel.org, jeremy.linton@arm.com, iommu@lists.linux-foundation.org, linux-rpi-kernel@lists.infradead.org, rientjes@google.com, Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============0649016993770056811==" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" --===============0649016993770056811== Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-BLB/tUqhN7FZgmlmL87f" --=-BLB/tUqhN7FZgmlmL87f Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2020-08-06 at 07:18 +0200, Christoph Hellwig wrote: > On Tue, Aug 04, 2020 at 11:43:15AM +0200, Nicolas Saenz Julienne wrote: > > > Second I don't see the need (and actually some harm) in preventing GF= P_KERNEL > > > allocations from dipping into lower CMA areas - something that we did= support > > > before 5.8 with the single pool. > >=20 > > My thinking is the least we pressure CMA the better, it's generally sca= rse, and > > it'll not grow as the atomic pools grow. As far as harm is concerned, w= e now > > check addresses for correctness, so we shouldn't run into problems. > >=20 > > There is a potential case for architectures defining a default CMA but = not > > defining DMA zones where this could be problematic. But isn't that just= plain > > abusing CMA? If you need low memory allocations, you should be defining= DMA > > zones. >=20 > The latter is pretty much what I expect, as we only support the default a= nd > per-device DMA CMAs. Fair enough, should I send a v3 with everything cleaned-up/rebased, or you'= d rather pick it up from your version? --=-BLB/tUqhN7FZgmlmL87f Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAl8r7oUACgkQlfZmHno8 x/6NNAf8CT1UiVU7PCKz2LUHhepxWBfqr/Fz15NMCjlWxLecIvE8NeFQYjnkzCr8 WNIEZM0Vi5yiy2M5Au0e18rt/S/U2O4wCD95KXIAO7b7iMhP0jJFh9nqnj6IDUrJ +QzQLSMHGGD+UO4bxtpONvZ0/UekL1werA7sP2qQynpUDFijzq8HZ9/U2tD+Mtyl CFUOvAI5xO6AsVH4xryG4jWUb66/hflTOJ2nwz6ybrN/R+L2UvxYrynf2/lHIZq/ wqfGMD/Oh+KAiecex8ZgavWC/Adft7bAfJ3E7JZp5V3C+wW/QB7XWeGtAAawy1nC B5Pd5WHQFwp5oP5bPzDO17kycEbD8Q== =DGkG -----END PGP SIGNATURE----- --=-BLB/tUqhN7FZgmlmL87f-- --===============0649016993770056811== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu --===============0649016993770056811==--