On Mon, Jul 06, 2009 at 09:47:09PM -0400, John David Anglin wrote: > > If I remember correctly, there's still some issues with the L2 cache on > > pa8800 that we haven't quite bothered to work out yet, since it's "good > > enough" for now. James probably knows more. It would be interesting to > > see if you could reproduce it with a UP 64-bit kernel on your C3750 to > > discount the L2 problems. > > Googling, I see Grant had trouble with RCU_TORTURE_TEST=y. Probably, > I should test current kernel to see if the problem is still present. > > I guess you are referring to this change: > http://fossplanet.com/linux.debian.devel.kernel.cvs/thread-4378354-r7141-patches/ > > I'm thinking we must be missing a flush... Maybe in clear_user_page > as for copy_user_page? > > Do the problematic debian buildd machines have pa8800/pa8900 processors? dannf@penalosa:~$ cat /proc/cpuinfo processor : 0 cpu family : PA-RISC 2.0 cpu : PA8700 (PCX-W2) cpu MHz : 750.000000 model : 9000/785/J6700 model name : Duet W2 hversion : 0x00005dd0 sversion : 0x00000491 I-cache : 768 KB D-cache : 1536 KB (WB, direct mapped) ITLB entries : 240 DTLB entries : 240 - shared with ITLB bogomips : 1495.04 software id : 2001606322 > My sense is that some change (probably to the core memory management > code) made the coherence issue worse post 2.6.22.x. > > Dave -- dann frazier -- 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
