Re: [Qemu-devel] [PATCH v5 01/25] scsi: add tracing of scsi requests

[Stefan Hajnoczi <stefanha@gmail.com>]

On Thu, May 26, 2011 at 9:20 PM, Blue Swirl <blauwirbel@gmail.com> wrote:
> On Thu, May 26, 2011 at 1:56 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>> ---
>>  hw/scsi-bus.c |    6 ++++++
>>  trace-events  |    6 ++++++
>>  2 files changed, 12 insertions(+), 0 deletions(-)
>>
>> diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
>> index ceeb4ec..0fd85fc 100644
>> --- a/hw/scsi-bus.c
>> +++ b/hw/scsi-bus.c
>> @@ -4,6 +4,7 @@
>>  #include "scsi-defs.h"
>>  #include "qdev.h"
>>  #include "blockdev.h"
>> +#include "trace.h"
>>
>>  static char *scsibus_get_fw_dev_path(DeviceState *dev);
>>
>> @@ -141,6 +142,7 @@ SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag, uint32_t l
>>     req->lun = lun;
>>     req->status = -1;
>>     req->enqueued = true;
>> +    trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
>>     QTAILQ_INSERT_TAIL(&d->requests, req, next);
>>     return req;
>>  }
>> @@ -159,6 +161,7 @@ SCSIRequest *scsi_req_find(SCSIDevice *d, uint32_t tag)
>>
>>  static void scsi_req_dequeue(SCSIRequest *req)
>>  {
>> +    trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
>>     if (req->enqueued) {
>>         QTAILQ_REMOVE(&req->dev->requests, req, next);
>>         req->enqueued = false;
>> @@ -195,6 +198,7 @@ static int scsi_req_length(SCSIRequest *req, uint8_t *cmd)
>>         req->cmd.len = 12;
>>         break;
>>     default:
>> +        trace_scsi_req_parse_bad(req->dev->id, req->lun, req->tag, cmd[0]);
>>         return -1;
>>     }
>>
>> @@ -392,6 +396,8 @@ int scsi_req_parse(SCSIRequest *req, uint8_t *buf)
>>     memcpy(req->cmd.buf, buf, req->cmd.len);
>>     scsi_req_xfer_mode(req);
>>     req->cmd.lba = scsi_req_lba(req);
>> +    trace_scsi_req_parsed(req->dev->id, req->lun, req->tag, buf[0],
>> +                          req->cmd.mode, req->cmd.xfer, req->cmd.lba);
>>     return 0;
>>  }
>>
>> diff --git a/trace-events b/trace-events
>> index 385cb00..b11b71d 100644
>> --- a/trace-events
>> +++ b/trace-events
>> @@ -205,6 +205,12 @@ disable usb_set_config(int addr, int config, int ret) "dev %d, config %d, ret %d
>>  disable usb_clear_device_feature(int addr, int feature, int ret) "dev %d, feature %d, ret %d"
>>  disable usb_set_device_feature(int addr, int feature, int ret) "dev %d, feature %d, ret %d"
>>
>> +# hw/scsi-bus.c
>> +disable scsi_req_alloc(int target, int lun, int tag) "target %d lun %d tag %d"
>> +disable scsi_req_dequeue(int target, int lun, int tag) "target %d lun %d tag %d"
>> +disable scsi_req_parsed(int target, int lun, int tag, int cmd, int mode, int xfer, uint64_t lba) "target %d lun %d tag %d command %d dir %d length %d lba %"PRIu64""
>> +disable scsi_req_parse_bad(int target, int lun, int tag, int cmd) "target %d lun %d tag %d command %d"
>
> Build fails with simpletrace enabled:
>  CC    oslib-posix.o
> cc1: warnings being treated as errors
> In file included from /src/qemu/oslib-posix.c:32:
> ./trace.h: In function 'trace_scsi_req_parsed':
> ./trace.h:716: error: implicit declaration of function 'trace7'
> ./trace.h:716: error: nested extern declaration of 'trace7'

The simple trace backend only records 6 arguments.  Either you can
eliminate an argument from this trace event or you could extend the
record size (and bump the version header).

Stefan