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authorK. Y. Srinivasan <kys@microsoft.com>2015-12-23 13:15:51 -0800
committerMartin K. Petersen <martin.petersen@oracle.com>2016-01-06 15:56:17 -0500
commit03996f2064a5c5b7c1bd942794d622179acf2d61 (patch)
treecd07b66915e27358e807fe4faa127f5e70dbb991 /drivers/scsi
parent59635018f9b7ae8b3e304d7a5da6f628b5a1dcf6 (diff)
downloadlinux-03996f2064a5c5b7c1bd942794d622179acf2d61.tar.bz2
storvsc: Tighten up the interrupt path
On the interrupt path, we repeatedly establish the pointer to the storvsc_device. While the compiler does inline get_in_stor_device() (and other static functions) in the call chain in the interrupt path, the compiler is repeatedly inlining the call to get_in_stor_device() each time it is invoked. The return value of get_in_stor_device() can be cached in the interrupt path since there is higher level serialization in place to ensure correct handling when the module unload races with the processing of an incoming message from the host. Optimize this code path by caching the pointer to storvsc_device and passing it as an argument. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Long Li <longli@microsoft.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/storvsc_drv.c23
1 files changed, 8 insertions, 15 deletions
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 811f276baed8..41c115c230d9 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);
#if IS_ENABLED(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);
}