From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935031AbbLRIwA (ORCPT ); Fri, 18 Dec 2015 03:52:00 -0500 Received: from mx2.suse.de ([195.135.220.15]:38588 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933772AbbLRIv5 (ORCPT ); Fri, 18 Dec 2015 03:51:57 -0500 Subject: Re: [PATCH V3 4/4] scsi: storvsc: Tighten up the interrupt path To: "K. Y. Srinivasan" , gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, ohering@suse.com, jbottomley@parallels.com, hch@infradead.org, linux-scsi@vger.kernel.org, apw@canonical.com, vkuznets@redhat.com, jasowang@redhat.com, martin.petersen@oracle.com References: <1450038486-19211-1-git-send-email-kys@microsoft.com> <1450038512-19252-1-git-send-email-kys@microsoft.com> <1450038512-19252-4-git-send-email-kys@microsoft.com> From: Hannes Reinecke Message-ID: <5673C92B.5070602@suse.de> Date: Fri, 18 Dec 2015 09:51:55 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <1450038512-19252-4-git-send-email-kys@microsoft.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/13/2015 09:28 PM, K. Y. Srinivasan wrote: > On the interrupt path, we repeatedly establish the pointer to the > storvsc_device. Fix this. > > Signed-off-by: K. Y. Srinivasan > Reviewed-by: Long Li > Reviewed-by: Johannes Thumshirn > Tested-by: Alex Ng > --- > drivers/scsi/storvsc_drv.c | 23 ++++++++--------------- > 1 files changed, 8 insertions(+), 15 deletions(-) > > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c > index d6ca4f2..b68aebe 100644 > --- a/drivers/scsi/storvsc_drv.c > +++ b/drivers/scsi/storvsc_drv.c > @@ -945,19 +945,16 @@ static void storvsc_handle_error(struct vmscsi_request *vm_srb, > } > > > -static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request) > +static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request, > + struct storvsc_device *stor_dev) > { > struct scsi_cmnd *scmnd = cmd_request->cmd; > - struct hv_host_device *host_dev = shost_priv(scmnd->device->host); > struct scsi_sense_hdr sense_hdr; > struct vmscsi_request *vm_srb; > struct Scsi_Host *host; > - struct storvsc_device *stor_dev; > - struct hv_device *dev = host_dev->dev; > u32 payload_sz = cmd_request->payload_sz; > void *payload = cmd_request->payload; > > - stor_dev = get_in_stor_device(dev); > host = stor_dev->host; > > vm_srb = &cmd_request->vstor_packet.vm_srb; > @@ -987,14 +984,13 @@ static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request) > kfree(payload); > } > > -static void storvsc_on_io_completion(struct hv_device *device, > +static void storvsc_on_io_completion(struct storvsc_device *stor_device, > struct vstor_packet *vstor_packet, > struct storvsc_cmd_request *request) > { > - struct storvsc_device *stor_device; > struct vstor_packet *stor_pkt; > + struct hv_device *device = stor_device->device; > > - stor_device = hv_get_drvdata(device); > stor_pkt = &request->vstor_packet; > > /* > @@ -1049,7 +1045,7 @@ static void storvsc_on_io_completion(struct hv_device *device, > stor_pkt->vm_srb.data_transfer_length = > vstor_packet->vm_srb.data_transfer_length; > > - storvsc_command_completion(request); > + storvsc_command_completion(request, stor_device); > > if (atomic_dec_and_test(&stor_device->num_outstanding_req) && > stor_device->drain_notify) > @@ -1058,21 +1054,19 @@ static void storvsc_on_io_completion(struct hv_device *device, > > } > > -static void storvsc_on_receive(struct hv_device *device, > +static void storvsc_on_receive(struct storvsc_device *stor_device, > struct vstor_packet *vstor_packet, > struct storvsc_cmd_request *request) > { > struct storvsc_scan_work *work; > - struct storvsc_device *stor_device; > > switch (vstor_packet->operation) { > case VSTOR_OPERATION_COMPLETE_IO: > - storvsc_on_io_completion(device, vstor_packet, request); > + storvsc_on_io_completion(stor_device, vstor_packet, request); > break; > > case VSTOR_OPERATION_REMOVE_DEVICE: > case VSTOR_OPERATION_ENUMERATE_BUS: > - stor_device = get_in_stor_device(device); > work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC); > if (!work) > return; > @@ -1083,7 +1077,6 @@ static void storvsc_on_receive(struct hv_device *device, > break; > > case VSTOR_OPERATION_FCHBA_DATA: > - stor_device = get_in_stor_device(device); > cache_wwn(stor_device, vstor_packet); > #ifdef CONFIG_SCSI_FC_ATTRS > fc_host_node_name(stor_device->host) = stor_device->node_name; > @@ -1133,7 +1126,7 @@ static void storvsc_on_channel_callback(void *context) > vmscsi_size_delta)); > complete(&request->wait_event); > } else { > - storvsc_on_receive(device, > + storvsc_on_receive(stor_device, > (struct vstor_packet *)packet, > request); > } > Hmm. I would've thought the compiler optimizes this away. Have you checked whether it actually makes a difference in the assembler output? Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)