From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwgVx-008GgK-8o for kexec@lists.infradead.org; Mon, 13 Dec 2021 08:16:54 +0000 Date: Mon, 13 Dec 2021 16:16:41 +0800 From: Baoquan He Subject: Re: [PATCH RESEND v2 2/5] dma-pool: allow user to disable atomic pool Message-ID: <20211213081641.GB29905@MiWiFi-R3L-srv> References: <20211207030750.30824-1-bhe@redhat.com> <20211207030750.30824-3-bhe@redhat.com> <20211213074404.GA20758@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211213074404.GA20758@lst.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, robin.murphy@arm.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, vbabka@suse.cz, m.szyprowski@samsung.com, John.p.donnelly@oracle.com, kexec@lists.infradead.org On 12/13/21 at 08:44am, Christoph Hellwig wrote: > On Tue, Dec 07, 2021 at 11:07:47AM +0800, Baoquan He wrote: > > In the current code, three atomic memory pools are always created, > > atomic_pool_kernel|dma|dma32, even though 'coherent_pool=0' is > > specified in kernel command line. In fact, atomic pool is only > > necessary when CONFIG_DMA_DIRECT_REMAP=y or mem_encrypt_active=y > > which are needed on few ARCHes. > > And only these select the atomic pool, so it won't get created otherwise. > What problem are you trying to solve? This tries to make "coherent_pool=0" behave normally. As you see, 'coherent_pool=0' will behave like no 'coherent_pool' being specified. This is not consistent with other similar kernel parameter, e.g cma=. At the beginning, I planned to add a knob to allow user to disable one or all atomic pool. Later I changed. However I think this patch makes sense on fixing the a little bizarre behaviour, 'coherent_pool=0' but still get atomic pool created. I can drop it if you think it's unnecessary. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec