diff options
| author | Fam Zheng <famz@redhat.com> | 2014-09-16 15:20:17 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-23 15:40:51 +0200 |
| commit | 61e68b3fbd3e2b7beb636bc56f78d9c1ca25e8f9 (patch) | |
| tree | 94312f417d4022a681392b1526c590a18924ceb2 /hw | |
| parent | 380f649e02f9545159dc3158d7c1b2e70c1005e3 (diff) | |
scsi: Optimize scsi_req_alloc
Zeroing sense buffer for each scsi request is not efficient, we can just
leave it uninitialized because sense_len is set to 0.
Move the implicitly zeroed fields to the end of the structure and use a
partial memset.
The explicitly initialized fields (by scsi_req_alloc or scsi_req_new)
are moved to the beginning of the structure, before sense buffer, to
skip the memset.
Also change g_malloc0 to g_slice_alloc.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/scsi/scsi-bus.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index 954c6072bf..af293b59da 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -551,8 +551,11 @@ SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d, SCSIRequest *req; SCSIBus *bus = scsi_bus_from_device(d); BusState *qbus = BUS(bus); + const int memset_off = offsetof(SCSIRequest, sense) + + sizeof(req->sense); - req = g_malloc0(reqops->size); + req = g_slice_alloc(reqops->size); + memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off); req->refcount = 1; req->bus = bus; req->dev = d; @@ -560,7 +563,6 @@ SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d, req->lun = lun; req->hba_private = hba_private; req->status = -1; - req->sense_len = 0; req->ops = reqops; object_ref(OBJECT(d)); object_ref(OBJECT(qbus->parent)); @@ -1603,7 +1605,7 @@ void scsi_req_unref(SCSIRequest *req) } object_unref(OBJECT(req->dev)); object_unref(OBJECT(qbus->parent)); - g_free(req); + g_slice_free1(req->ops->size, req); } } |