From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e3.ny.us.ibm.com (e3.ny.us.ibm.com [32.97.182.143]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e3.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 1E16FDDED7 for ; Wed, 29 Apr 2009 02:02:54 +1000 (EST) Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e3.ny.us.ibm.com (8.13.1/8.13.1) with ESMTP id n3SFwwp9027569 for ; Tue, 28 Apr 2009 11:58:58 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n3SG2nrA090474 for ; Tue, 28 Apr 2009 12:02:49 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n3SG2nKj009086 for ; Tue, 28 Apr 2009 12:02:49 -0400 From: Stefan Roscher To: Dave Hansen Subject: Re: [PATCH 1/3] IB/ehca: Replace vmalloc with kmalloc Date: Tue, 28 Apr 2009 18:02:47 +0200 References: <200904211716.45245.ossrosch@linux.vnet.ibm.com> <1240931572.29485.77.camel@nimitz> In-Reply-To: <1240931572.29485.77.camel@nimitz> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Message-Id: <200904281802.47809.ossrosch@linux.vnet.ibm.com> Cc: fenkes@de.ibm.com, LKML , LinuxPPC-Dev , raisch@de.ibm.com, alexschm@de.ibm.com, stefan.roscher@de.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tuesday 28 April 2009 05:12:51 pm Dave Hansen wrote: > On Tue, 2009-04-21 at 17:16 +0200, Stefan Roscher wrote: > > From: Anton Blanchard > > > > To improve performance of driver ressource allocation, > > replace the vmalloc() call with kmalloc(). > > Just curious, but how big are these allocations? Why was vmalloc() even > ever used if we know they'll be small? > > -- Dave > > The theoretical maximum size can be 512k, but for common queue pairs less than 128k is used.Because of the theoretical maximum we implemented vmalloc() first, but recognized a huge performance impact. -- Stefan From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757074AbZD1QDl (ORCPT ); Tue, 28 Apr 2009 12:03:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932622AbZD1QCv (ORCPT ); Tue, 28 Apr 2009 12:02:51 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:41388 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932604AbZD1QCu (ORCPT ); Tue, 28 Apr 2009 12:02:50 -0400 From: Stefan Roscher To: Dave Hansen Subject: Re: [PATCH 1/3] IB/ehca: Replace vmalloc with kmalloc Date: Tue, 28 Apr 2009 18:02:47 +0200 User-Agent: KMail/1.9.9 Cc: "LinuxPPC-Dev" , LKML , Roland Dreier , fenkes@de.ibm.com, raisch@de.ibm.com, alexschm@de.ibm.com, stefan.roscher@de.ibm.com, hnguyen@de.ibm.com References: <200904211716.45245.ossrosch@linux.vnet.ibm.com> <1240931572.29485.77.camel@nimitz> In-Reply-To: <1240931572.29485.77.camel@nimitz> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200904281802.47809.ossrosch@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 28 April 2009 05:12:51 pm Dave Hansen wrote: > On Tue, 2009-04-21 at 17:16 +0200, Stefan Roscher wrote: > > From: Anton Blanchard > > > > To improve performance of driver ressource allocation, > > replace the vmalloc() call with kmalloc(). > > Just curious, but how big are these allocations? Why was vmalloc() even > ever used if we know they'll be small? > > -- Dave > > The theoretical maximum size can be 512k, but for common queue pairs less than 128k is used.Because of the theoretical maximum we implemented vmalloc() first, but recognized a huge performance impact. -- Stefan