On Mon, Mar 10, 2014 at 10:01:58PM -0700, Andrew Morton wrote: > On Tue, 11 Mar 2014 00:51:09 -0400 Dave Jones <davej@xxxxxxxxxx> wrote: > > > On Mon, Mar 10, 2014 at 09:46:12PM -0700, Andrew Morton wrote: > > > On Mon, 10 Mar 2014 20:13:40 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > Anyone ? I'm hitting this trace on an almost daily basis, which is a pain > > > > > while trying to reproduce a different bug.. > > > > > > > > Damn, I thought we'd fixed that but it seems not. Cc's added. > > > > > > > > Guys, what stops the migration target page from coming unlocked in > > > > parallel with zap_pte_range()'s call to migration_entry_to_page()? > > > > > > page_table_lock, sort-of. At least, transitions of is_migration_entry() > > > and page_locked() happen under ptl. > > > > > > I don't see any holes in regular migration. Do you know if this is > > > reproducible with CONFIG_NUMA_BALANCING=n or CONFIG_NUMA=n? > > > > CONFIG_NUMA_BALANCING was n already btw, so I'll do a NUMA=n run. > > There probably isn't much point unless trinity is using > sys_move_pages(). Is it? Trinity will do every syscall an arch has. In the test case I have so far, I've narrowed it down to the vm group of syscalls (so running with '-g vm' will do anything that I deemed 'vm'. Including.. sys_move_pages) I'll try to narrow it down further tomorrow. > If so it would be interesting to disable > trinity's move_pages calls and see if it still fails. Ok, I'll try that first. > Grasping at straws here, trying to reduce the amount of code to look at :( *nod*, it's not helped by the fact that the trace happens at process exit time which could be considerably later after the syscall that buggers everything up has happened. Dave -- 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>