Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755764AbZDVQcA (ORCPT ); Wed, 22 Apr 2009 12:32:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752910AbZDVQbv (ORCPT ); Wed, 22 Apr 2009 12:31:51 -0400 Received: from static-88-194-224-77.ipcom.comunitel.net ([77.224.194.88]:39794 "EHLO panicking.kicks-ass.org" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752930AbZDVQbu (ORCPT ); Wed, 22 Apr 2009 12:31:50 -0400 Message-ID: <49EF254A.6020106@evidence.eu.com> Date: Wed, 22 Apr 2009 16:10:18 +0200 From: michael User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: Stefan Roscher CC: Roland Dreier , fenkes@de.ibm.com, LKML , OF-EWG , LinuxPPC-Dev , raisch@de.ibm.com, alexschm@de.ibm.com, stefan.roscher@de.ibm.com Subject: Re: [PATCH 1/3] IB/ehca: Replace vmalloc with kmalloc References: <200904211716.45245.ossrosch@linux.vnet.ibm.com> <200904221602.29028.ossrosch@linux.vnet.ibm.com> In-Reply-To: <200904221602.29028.ossrosch@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2797 Lines: 83 Hi, Stefan Roscher wrote: > In case of large queue pairs there is the possibillity of allocation failures > due to memory fragmentationo with kmalloc().To ensure the memory is allocated even > if kmalloc() can not find chunks which are big enough, we try to allocate the memory > with vmalloc(). > > Signed-off-by: Stefan Roscher > --- > > On Tuesday 21 April 2009 07:34:30 pm Roland Dreier wrote: > >> > + queue->queue_pages = kmalloc(nr_of_pages * sizeof(void *), GFP_KERNEL); >> >> How big might this buffer be? Any chance of allocation failure due to >> memory fragmentation? >> >> - R. >> > Hey Roland, > yes you are right and here is the patch to circumvent the described problem. > It will apply on top of the patchset. > regards Stefan > > I don't take the point, if it is not import use the vmalloc. Why you try with a kmalloc alloc first? and why do not use kzalloc? > > drivers/infiniband/hw/ehca/ipz_pt_fn.c | 17 +++++++++++++---- > 1 files changed, 13 insertions(+), 4 deletions(-) > > diff --git a/drivers/infiniband/hw/ehca/ipz_pt_fn.c b/drivers/infiniband/hw/ehca/ipz_pt_fn.c > index a260559..1227c59 100644 > --- a/drivers/infiniband/hw/ehca/ipz_pt_fn.c > +++ b/drivers/infiniband/hw/ehca/ipz_pt_fn.c > @@ -222,8 +222,11 @@ int ipz_queue_ctor(struct ehca_pd *pd, struct ipz_queue *queue, > /* allocate queue page pointers */ > queue->queue_pages = kmalloc(nr_of_pages * sizeof(void *), GFP_KERNEL); > if (!queue->queue_pages) { > - ehca_gen_err("Couldn't allocate queue page list"); > - return 0; > + queue->queue_pages = vmalloc(nr_of_pages * sizeof(void *)); > + if (!queue->queue_pages) { > + ehca_gen_err("Couldn't allocate queue page list"); > + return 0; > + } > } > memset(queue->queue_pages, 0, nr_of_pages * sizeof(void *)); > > @@ -240,7 +243,10 @@ int ipz_queue_ctor(struct ehca_pd *pd, struct ipz_queue *queue, > ipz_queue_ctor_exit0: > ehca_gen_err("Couldn't alloc pages queue=%p " > "nr_of_pages=%x", queue, nr_of_pages); > - kfree(queue->queue_pages); > + if (is_vmalloc_addr(queue->queue_pages)) > + vfree(queue->queue_pages); > + else > + kfree(queue->queue_pages); > > return 0; > } > @@ -262,7 +268,10 @@ int ipz_queue_dtor(struct ehca_pd *pd, struct ipz_queue *queue) > free_page((unsigned long)queue->queue_pages[i]); > } > > - kfree(queue->queue_pages); > + if (is_vmalloc_addr(queue->queue_pages)) > + vfree(queue->queue_pages); > + else > + kfree(queue->queue_pages); > > return 1; > } > Regards Michael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/