On 05/30/2013 05:01 PM, Helge Deller wrote: > On 05/30/2013 04:55 PM, James Bottomley wrote: >> On Tue, 2013-05-28 at 08:09 -0400, John David Anglin wrote: >>> There are two issues addressed by this patch: >>> >>> 1) When we flush user instruction and data pages using the kernel >>> tmpalias region, we need to >>> ensure that the local TLB entry for the tmpalias page is never >>> replaced with a different mapping. >>> Previously, we purged the entry before and after the cache flush >>> loop. Although preemption was >>> disabled, it seemed possible that the value might change during >>> interrupt processing. The patch >>> removes the purge and disables interrupts during the initial TLB entry >>> purge and cache flush. >>> >>> 2) In a number of places, we flush the TLB for the page and then flush >>> the page. We disabled >>> preemption around the flush. This change disables preemption around >>> both the TLB and cache >>> flushes as it seemed the effect of the purge might be lost. >>> >>> Without this change, I saw four random segmentation faults in about >>> 1.5 days of intensive package >>> building last weekend. With the change, I haven't seen a single >>> random segmentation fault in about >>> one week of building Debian packages on 4-way rp3440. So, there is a >>> significant improvement >>> in system stability. >> >> an rp3440 is PA2.0, so you weren't really testing any of the tlb purge >> locking changes. > > Which kind of system do we need to test those "tlb purge locking changes" (PAx.y)? > At least I can confirm, that Dave's patches have made all my systems > absolutely stable. For those who want to test right now, you can check out the "for-next" branch of: git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git in which I've queue up the outstanding patches for 3.10... (web: http://git.kernel.org/cgit/linux/kernel/git/deller/parisc-linux.git/log/?h=for-next) Helge -- 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
