On Wed, Mar 16, 2011 at 10:49 AM, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote: > Hi... > > On Thu, Mar 17, 2011 at 00:26, va stg2010 <va.storage2010@xxxxxxxxx> wrote: >> I also looked into sg_miter_next() and sg_miter_stop() >> implementations. They are calling kmap_atomic() and >> kunmap_atomic() respectively. Based on comment -- Is following an >> illegal operation? and why? >> 1) IRQ disabled >> 2) sg_miter_next , meaning kmap_atomic >> 3) IRQ enabled >> 4) IRQ disabled again little later >> 5) sg_miter_stop, meaning kunmap_atomic() >> >> The above sequence caused following scheduler messages (if >> sg_miter_stop() is moved between step1 & step3 then following error >> messages disappeared) :-------- >> BUG: scheduling while atomic: swapper/0/0xffffffff >> Modules linked in: my_scsi_lld > > quite likely the error was triggered not due to kmap_atomic() and > kunmap_atomic(), but due to something that you do toward the page > allocated via kmap_atomic() itself. The page is given to my scsi mid layer LLDD by linux-scsi layer for SCSI read request. When sg_miter_stop() happens the page will have READ data available and I call scsi_done(). _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
