>> Can't we have another way to fix ? like this ? too ugly ? >> Again, I'm sorry if I misunderstand the points. >> > Sorry this patch itself may be buggy. please don't test.. > I missed that kernel/exit.c sets task->mempolicy to be NULL. > fixed one here. > > -- > From 5581c71e68a7f50e52fd67cca00148911023f9f5 Mon Sep 17 00:00:00 2001 > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > Date: Thu, 18 Oct 2012 13:50:29 +0900 > > Subject: [PATCH] hold task->mempolicy while numa_maps scans. > > /proc/<pid>/numa_maps scans vma and show mempolicy under > mmap_sem. It sometimes accesses task->mempolicy which can > be freed without mmap_sem and numa_maps can show some > garbage while scanning. > > This patch tries to take reference count of task->mempolicy at reading > numa_maps before calling get_vma_policy(). By this, task->mempolicy > will not be freed until numa_maps reaches its end. > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > > V1->V2 > - access task->mempolicy only once and remember it. Becase kernel/exit.c > can overwrite it. > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Ok, this is acceptable to me. go ahead. -- 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>