On Wed, Feb 6, 2013 at 5:10 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 06 Feb 2013 19:39:11 -0500 > Sasha Levin <sasha.levin@xxxxxxxxxx> wrote: > >> We're now hitting the VM_BUG_ON() which was added in the last hunk of the >> patch: > > hm, why was that added. > > Michel, I seem to have confused myself over this series. I saw a > report this morning which led me to drop > mm-accelerate-munlock-treatment-of-thp-pages.patch but now I can't find > that report and I'm wondering if I should have dropped > mm-accelerate-mm_populate-treatment-of-thp-pages.patch instead. > > Given that and Sasha's new report I think I'll drop > > mm-use-long-type-for-page-counts-in-mm_populate-and-get_user_pages.patch > mm-use-long-type-for-page-counts-in-mm_populate-and-get_user_pages-fix.patch > mm-use-long-type-for-page-counts-in-mm_populate-and-get_user_pages-fix-fix.patch > mm-accelerate-mm_populate-treatment-of-thp-pages.patch > mm-accelerate-munlock-treatment-of-thp-pages.patch > > and let's start again? All right. My bad, there were issues in the patch series. I think there were two: - The VM_BUG_ON(!reg) in "mm: use long type for page counts in mm_populate() and get_user_pages()". The intention there was to test for what happened in the original overflow case, which is that gup would return 0 as the passed nr_pages argument (when passed as an int) would be <= 0. As it turns out, this didn't account for the other case where gup returns 0, which is when the first page is file-backed, not found in page cache, and the mmap_sem gets dropped due to a non-NULL "nonblocking" argument (as is the case with mm_populate()) - The issue in munlock, where the page mask wasn't correctly computed due to an off by 1 issue. I agree a clean resend seems the most appropriate course of action at this point. Sorry for the trouble :/ -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>