From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm: replace TIF_MEMDIE checks by tsk_is_oom_victim TIF_MEMDIE is set only to the tasks whick were either directly selected by the OOM killer or passed through mark_oom_victim from the allocator path. tsk_is_oom_victim is more generic and allows to identify all tasks (threads) which share the mm with the oom victim. Please note that the freezer still needs to check TIF_MEMDIE because we cannot thaw tasks which do not participage in oom_victims counting otherwise a !TIF_MEMDIE task could interfere after oom_disbale returns. Link: http://lkml.kernel.org/r/20170810075019.28998-3-mhocko@xxxxxxxxxx Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/cgroup/cpuset.c | 9 +++++---- mm/memcontrol.c | 2 +- 2 files changed, 6 insertions(+), 5 deletions(-) diff -puN kernel/cgroup/cpuset.c~mm-replace-tif_memdie-checks-by-tsk_is_oom_victim kernel/cgroup/cpuset.c --- a/kernel/cgroup/cpuset.c~mm-replace-tif_memdie-checks-by-tsk_is_oom_victim +++ a/kernel/cgroup/cpuset.c @@ -56,6 +56,7 @@ #include <linux/time64.h> #include <linux/backing-dev.h> #include <linux/sort.h> +#include <linux/oom.h> #include <linux/uaccess.h> #include <linux/atomic.h> @@ -2500,12 +2501,12 @@ static struct cpuset *nearest_hardwall_a * If we're in interrupt, yes, we can always allocate. If @node is set in * current's mems_allowed, yes. If it's not a __GFP_HARDWALL request and this * node is set in the nearest hardwalled cpuset ancestor to current's cpuset, - * yes. If current has access to memory reserves due to TIF_MEMDIE, yes. + * yes. If current has access to memory reserves as an oom victim, yes. * Otherwise, no. * * GFP_USER allocations are marked with the __GFP_HARDWALL bit, * and do not allow allocations outside the current tasks cpuset - * unless the task has been OOM killed as is marked TIF_MEMDIE. + * unless the task has been OOM killed. * GFP_KERNEL allocations are not so marked, so can escape to the * nearest enclosing hardwalled ancestor cpuset. * @@ -2528,7 +2529,7 @@ static struct cpuset *nearest_hardwall_a * affect that: * in_interrupt - any node ok (current task context irrelevant) * GFP_ATOMIC - any node ok - * TIF_MEMDIE - any node ok + * tsk_is_oom_victim - any node ok * GFP_KERNEL - any node in enclosing hardwalled cpuset ok * GFP_USER - only nodes in current tasks mems allowed ok. */ @@ -2546,7 +2547,7 @@ bool __cpuset_node_allowed(int node, gfp * Allow tasks that have access to memory reserves because they have * been OOM killed to get memory anywhere. */ - if (unlikely(test_thread_flag(TIF_MEMDIE))) + if (unlikely(tsk_is_oom_victim(current))) return true; if (gfp_mask & __GFP_HARDWALL) /* If hardwall request, stop here */ return false; diff -puN mm/memcontrol.c~mm-replace-tif_memdie-checks-by-tsk_is_oom_victim mm/memcontrol.c --- a/mm/memcontrol.c~mm-replace-tif_memdie-checks-by-tsk_is_oom_victim +++ a/mm/memcontrol.c @@ -1917,7 +1917,7 @@ retry: * bypass the last charges so that they can exit quickly and * free their memory. */ - if (unlikely(test_thread_flag(TIF_MEMDIE) || + if (unlikely(tsk_is_oom_victim(current) || fatal_signal_pending(current) || current->flags & PF_EXITING)) goto force; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
