On Wed, 2015-11-18 at 17:36 -0700, Ross Zwisler wrote: > On Wed, Nov 18, 2015 at 03:04:41PM -0700, Toshi Kani wrote: > > On Wed, 2015-11-18 at 13:57 -0800, Dan Williams wrote: > > > On Wed, Nov 18, 2015 at 1:33 PM, Toshi Kani <toshi.kani@xxxxxxx> wrote: > > > > I am seeing a similar/same problem in my test. I think the problem is > > > > that in case of a WP fault, wp_huge_pmd() -> __dax_pmd_fault() -> > > > > vmf_insert_pfn_pmd(), which is a no-op since the PMD is mapped already. > > > > We need WP handling for this PMD map. > > > > > > > > If it helps, I have attached change for follow_trans_huge_pmd(). I have > > > > not tested much, though. > > > > > > Interesting, I didn't get this far because my tests were crashing the > > > kernel. I'll add this case the pmd fault test in ndctl. > > > > I hit this one with mmap(MAP_POPULATE). With this change, I then hit the WP > > fault loop when writing to the range. > > Here's a fix - please let me know if this seems incomplete or incorrect for > some reason. My test looks working now. :-) I will do more testing and submit the gup patch as well. Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
