Re: [linuxsh-shmedia-dev] Re: [linuxsh-shmedia-bk] bk commit: curnowr@linsvr6.uk.superh.com:/build/archbuild/swbuild/curnowr/linux-2.4-tlb

[Richard C. <Ric...@su...>]

Hi Paul,

* Paul Mundt <le...@li...> [2003-07-01]:
> On Tue, Jul 01, 2003 at 03:01:55PM +0100, Richard Curnow wrote:
> >      			sg[i].dma_address = page_to_bus(sg[i].page) +
> >      					    sg[i].offset;
> >     +			dma_cache_wback_inv((unsigned long) bus_to_virt(sg[i].dma_address), sg[i].length);
> >      
> If you do this, you'll also want to do a similar flush in pci_unmap_sg(). I
> don't know if this is specifically needed, since on anything else requiring
> coherency, it seems to be omitted.

As far as I can tell, I've got the disc working reliably now.  Some
experiments that I've done are:

* a workload of 2 compilations, a configure (all these 3 in a while true
  loop with make {dist}clean), top, X, 2x gkrellm, several xterms & 7 or
  8 instances of our 'burnout' program.  The load average was over 13,
  and the Cayman was 70-110Mb deep in swap with periodic bursts of
  intense swap in and swap out activity.  This ran without a hitch for
  44 minutes until it died with a PCI ARB and the SCSI bus got wedged.
  I think this is reasonably convincing in itself that the SCSI access
  is now reliable.

* I mirrored my NFS filesystems onto the SCSI disc partitions, and
  modified the GDB download script to make root=/dev/sda1 on the
  command line.  For several boots I had the root and home filesystems
  on the SCSI, with no NFS discs brought up at all.  However, I've
  discontinued this just for now because I need to do more work with the
  shell scripts run by init to get fsck, umount etc working properly on
  boot and shutdown.

During these trials, I had flush_dcache_page inside flush_page_to_ram.
I need to do more runs to evaluate where we stand now on making
flush_page_to_ram a no-op again.

I'm currently merging from the external BK and retesting, then I'll push
this fix out.

Cheers
Richard

-- 
Richard \\\ SuperH Core+Debug Architect /// .. At home ..
  P.    /// ric...@su...  ///  rc...@rc...
Curnow  \\\ http://www.superh.com/    ///  www.rc0.org.uk