From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f41.google.com (mail-qg0-f41.google.com [209.85.192.41]) by kanga.kvack.org (Postfix) with ESMTP id 64BC56B0005 for ; Thu, 7 Apr 2016 11:11:58 -0400 (EDT) Received: by mail-qg0-f41.google.com with SMTP id c6so65620703qga.1 for ; Thu, 07 Apr 2016 08:11:58 -0700 (PDT) Received: from na01-bl2-obe.outbound.protection.outlook.com (mail-bl2on0081.outbound.protection.outlook.com. [65.55.169.81]) by mx.google.com with ESMTPS id z69si6246850qgd.9.2016.04.07.08.11.57 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 07 Apr 2016 08:11:57 -0700 (PDT) Subject: Re: [Lsf] [Lsf-pc] [LSF/MM TOPIC] Generic page-pool recycle facility? References: <1460034425.20949.7.camel@HansenPartnership.com> <20160407161715.52635cac@redhat.com> <20160407143854.GA7685@infradead.org> From: Bart Van Assche Message-ID: <570678B7.7010802@sandisk.com> Date: Thu, 7 Apr 2016 08:11:51 -0700 MIME-Version: 1.0 In-Reply-To: <20160407143854.GA7685@infradead.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig , Jesper Dangaard Brouer Cc: James Bottomley , Tom Herbert , Brenden Blanco , "lsf@lists.linux-foundation.org" , linux-mm , "netdev@vger.kernel.org" , "lsf-pc@lists.linux-foundation.org" , Alexei Starovoitov On 04/07/16 07:38, Christoph Hellwig wrote: > This is also very interesting for storage targets, which face the same > issue. SCST has a mode where it caches some fully constructed SGLs, > which is probably very similar to what NICs want to do. I think a cached allocator for page sets + the scatterlists that describe these page sets would not only be useful for SCSI target implementations but also for the Linux SCSI initiator. Today the scsi-mq code reserves space in each scsi_cmnd for a scatterlist of SCSI_MAX_SG_SEGMENTS. If scatterlists would be cached together with page sets less memory would be needed per scsi_cmnd. See also scsi_mq_setup_tags() and scsi_alloc_sgtable(). Bart. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org