From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Date: Wed, 01 Apr 2015 01:01:31 +0000 Subject: Re: [PATCH v8 RFC 0/3] Generic IOMMU pooled allocator Message-Id: <1427850091.20500.150.camel@kernel.crashing.org> List-Id: References: <20150331180642.GA13314@oracle.com> In-Reply-To: <20150331180642.GA13314@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sowmini Varadhan Cc: aik@au1.ibm.com, anton@au1.ibm.com, paulus@samba.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net On Tue, 2015-03-31 at 14:06 -0400, Sowmini Varadhan wrote: > Having bravely said that.. > > the IB team informs me that they see a 10% degradation using > the spin_lock as opposed to the trylock. > > one path going forward is to continue processing this patch-set > as is. I can investigate this further, and later revise the spin_lock > to the trylock, after we are certain that it is good/necessary. Have they tried using more pools instead ? Cheers, Ben. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id A5A601A0145 for ; Wed, 1 Apr 2015 12:01:49 +1100 (AEDT) Message-ID: <1427850091.20500.150.camel@kernel.crashing.org> Subject: Re: [PATCH v8 RFC 0/3] Generic IOMMU pooled allocator From: Benjamin Herrenschmidt To: Sowmini Varadhan Date: Wed, 01 Apr 2015 12:01:31 +1100 In-Reply-To: <20150331180642.GA13314@oracle.com> References: <20150331180642.GA13314@oracle.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: aik@au1.ibm.com, anton@au1.ibm.com, paulus@samba.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2015-03-31 at 14:06 -0400, Sowmini Varadhan wrote: > Having bravely said that.. > > the IB team informs me that they see a 10% degradation using > the spin_lock as opposed to the trylock. > > one path going forward is to continue processing this patch-set > as is. I can investigate this further, and later revise the spin_lock > to the trylock, after we are certain that it is good/necessary. Have they tried using more pools instead ? Cheers, Ben.