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[Xen-devel] problems of 'blktap'

  • To: Xen-devel@xxxxxxxxxxxxxxxxxxx
  • From: 李敏 <fly.limin@xxxxxxxxx>
  • Date: Tue, 3 Mar 2009 18:02:47 +0800
  • Cc:
  • Delivery-date: Tue, 03 Mar 2009 02:03:16 -0800
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when I am studying blktap mechanism , I faced a problem that I can't understand.
In tapdisk.c(xen-3.3.0/tools/blktap/drivers) line 687-689
page  = (char *)MMAP_VADDR(info->vstart,
         (unsigned long)req->id, i);
   page += (req->seg[i].first_sect << SECTOR_SHIFT);
how was the page address caculated?  I am not quite understanding.
thanks a lot!
Min Li
School of Computer Science and Technology
Cluster and Grid Computing Lab
Services Computing Technology and System Lab
Huazhong University of Science and Technology
Wuhan, 430074, China
Tel: 13986251431 027-65236831
Email: fly.limin@xxxxxxxxx
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