On Fri, 26 Aug 2005, Kai Makisara wrote: > On Thu, 25 Aug 2005, Andrew Morton wrote: > > > > > > > Begin forwarded message: > > > > Date: Tue, 23 Aug 2005 12:53:38 -0700 > > From: bugme-daemon@xxxxxxxxxxxxxxxxxxxx > > To: bugme-new@xxxxxxxxxxxxxx > > Subject: [Bugme-new] [Bug 5117] New: Panic when accessing scsi-tapedrives with 4G-remap > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=5117 > > > > Summary: Panic when accessing scsi-tapedrives with 4G-remap > > Kernel Version: 2.6.12.5 > > > > > > Could this purely be a highmem problem? Is the zero-copy DMA feature of > > st.c known to work OK with x86 highmem? > > It is _not_ known _not_ to work ;-) I.e., I have received neither any > success nor any failure reports. I have not tested it because I don't have > any machine with enough memory (and I have not hacked a kernel to use > highmem with 512 MB of memory). I hope someone seeing this thread and > using highmem with tape can comment on this subject. > OK. I booted my test i386 machine with highmem=384m and did some tests. I also added a counter to st.c to count the highmem pages used for zero-copy DMA. I could not get dd to use highmem but with tar that succeeded. No extra messages were found in syslog during these tests. BUT, at the same time I remembered that the system in the Bugzilla report was Athlon64 running FC3 x86_64. The x86_64 kernel does not have highmem. -- Kai - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
