On Tue, 24 Nov 2015, Helge Deller wrote: > * Mikulas Patocka <mpatocka@xxxxxxxxxx>: > > > > > > On Tue, 24 Nov 2015, Helge Deller wrote: > > > > > > Hi > > > > > > > > Since the kernel 4.4-rc2 I'm getting frequent boot failures on PA-RISC. > > > > When I revert this patchset, the crashes are gone. > > > > > > > [ 3.296666] CPU(s): 4 out of 4 PA8900 (Shortfin) at 1000.000000 MHz online > > > > > > Hi Mikulas, > > > > > > Yes, I've seen this as well. > > > It affects only the PA8900 CPUs, while all PA8500-PA8700 machines seem to work fine. > > > I do have a temporary 3-line patch to avoid the crashes which I'll push to my tree shortly. > > > I'm still investigating why it only affects the PA8900 CPUs, but I assume > > > it's related to the cache aliasing of those CPUs. > > > I'll keep you updated. > > > > > > Helge > > > > The PA-RISC specification doesn't allow aliasing on non-equaivalent > > addresses. Can the kernel map a piece of kernel data to other virtual > > address? If yes, we can't use big pages to map kernel data. > > Can you please try the two patches below? > The first one disables mapping kernel text/data on huge pages on > PA8800/PA8900 CPUs. Patch works for me on my Mako PA8800. > > Independend of my huge page patch the second patch disables the tlb > flush optimization we added earlier. It seems calling flush_tlb_all() > doesn't reliably flushes tlbs on all CPUs so it's better to fall back to > the loop implementation. > > Helge The kernel with these patches works fine so far. Mikulas -- 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
