On Fri, 2009-07-10 at 11:55 -0400, John David Anglin wrote: > > But I'm still wondering what the effect of this bug will be. > > The first order (not setting U-bit) should only affect ZX1 (pa8800/pa8900) > > machines. Those have uncacheable IO space between 2GB-4GB physical address. > > My guess is the machines should HPMC since the CPU would attempt to access > > those ranges as a cacheline read/write instead of sub-cacheline transactions. > > I think the depdi change may fix the random memory corruption that > I have been complaining about. My rp3440 has got through a full build > of GCC with 2.6.30.1. Previous two attempts failed with segmentation > faults in the dynamic loader, one of which I reported on. It will > take a few more builds to be sure. Your comment would explain why I > don't see this on c3750. Could this affect PA8700? In theory it would affect every box running a 64 bit kernel. We actually set PAGE_NO_CACHE on ioremaps(), so it's spreading out from the PCI device space. > I installed the change on my rp3440, c3750 and gsyprf11 last night. > At some point, I need to test the change with an SMP build on the rp3440. rp3440 is a pa88/8900 system? We have ion in the test ring at cupertino, it's a 4 CPU pa8900 ... I've been keeping it up to date with debian testing. > There is one other issue that I see on the rp3440 which I don't see > on the c3750 or gsyprf11. I get occassional testsuite timeouts during > compilation on compilations that shouldn't timeout. I had always > thought this to be a tcl/expect issue, but now I think this is likely > a kernel issue. I need to change the timeout value in the testsuite > to something big so I can see what's happening. It sounds a bit like another caching issue ... perhaps a cached value for a spinlock or futex making the thread thing the lock is held against it when it isn't? James -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
