From 6e0fc46dc2152d3e2d25a5d5b640ae3586c247c6 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Tue, 8 Sep 2015 15:00:36 -0700 Subject: mm, oom: organize oom context into struct There are essential elements to an oom context that are passed around to multiple functions. Organize these elements into a new struct, struct oom_control, that specifies the context for an oom condition. This patch introduces no functional change. Signed-off-by: David Rientjes Acked-by: Michal Hocko Cc: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 115 +++++++++++++++++++++++++++------------------------------- 1 file changed, 54 insertions(+), 61 deletions(-) (limited to 'mm/oom_kill.c') diff --git a/mm/oom_kill.c b/mm/oom_kill.c index dff991e0681e..80a7cbd89d66 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -196,27 +196,26 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, * Determine the type of allocation constraint. */ #ifdef CONFIG_NUMA -static enum oom_constraint constrained_alloc(struct zonelist *zonelist, - gfp_t gfp_mask, nodemask_t *nodemask, - unsigned long *totalpages) +static enum oom_constraint constrained_alloc(struct oom_control *oc, + unsigned long *totalpages) { struct zone *zone; struct zoneref *z; - enum zone_type high_zoneidx = gfp_zone(gfp_mask); + enum zone_type high_zoneidx = gfp_zone(oc->gfp_mask); bool cpuset_limited = false; int nid; /* Default to all available memory */ *totalpages = totalram_pages + total_swap_pages; - if (!zonelist) + if (!oc->zonelist) return CONSTRAINT_NONE; /* * Reach here only when __GFP_NOFAIL is used. So, we should avoid * to kill current.We have to random task kill in this case. * Hopefully, CONSTRAINT_THISNODE...but no way to handle it, now. */ - if (gfp_mask & __GFP_THISNODE) + if (oc->gfp_mask & __GFP_THISNODE) return CONSTRAINT_NONE; /* @@ -224,17 +223,18 @@ static enum oom_constraint constrained_alloc(struct zonelist *zonelist, * the page allocator means a mempolicy is in effect. Cpuset policy * is enforced in get_page_from_freelist(). */ - if (nodemask && !nodes_subset(node_states[N_MEMORY], *nodemask)) { + if (oc->nodemask && + !nodes_subset(node_states[N_MEMORY], *oc->nodemask)) { *totalpages = total_swap_pages; - for_each_node_mask(nid, *nodemask) + for_each_node_mask(nid, *oc->nodemask) *totalpages += node_spanned_pages(nid); return CONSTRAINT_MEMORY_POLICY; } /* Check this allocation failure is caused by cpuset's wall function */ - for_each_zone_zonelist_nodemask(zone, z, zonelist, - high_zoneidx, nodemask) - if (!cpuset_zone_allowed(zone, gfp_mask)) + for_each_zone_zonelist_nodemask(zone, z, oc->zonelist, + high_zoneidx, oc->nodemask) + if (!cpuset_zone_allowed(zone, oc->gfp_mask)) cpuset_limited = true; if (cpuset_limited) { @@ -246,20 +246,18 @@ static enum oom_constraint constrained_alloc(struct zonelist *zonelist, return CONSTRAINT_NONE; } #else -static enum oom_constraint constrained_alloc(struct zonelist *zonelist, - gfp_t gfp_mask, nodemask_t *nodemask, - unsigned long *totalpages) +static enum oom_constraint constrained_alloc(struct oom_control *oc, + unsigned long *totalpages) { *totalpages = totalram_pages + total_swap_pages; return CONSTRAINT_NONE; } #endif -enum oom_scan_t oom_scan_process_thread(struct task_struct *task, - unsigned long totalpages, const nodemask_t *nodemask, - bool force_kill) +enum oom_scan_t oom_scan_process_thread(struct oom_control *oc, + struct task_struct *task, unsigned long totalpages) { - if (oom_unkillable_task(task, NULL, nodemask)) + if (oom_unkillable_task(task, NULL, oc->nodemask)) return OOM_SCAN_CONTINUE; /* @@ -267,7 +265,7 @@ enum oom_scan_t oom_scan_process_thread(struct task_struct *task, * Don't allow any other task to have access to the reserves. */ if (test_tsk_thread_flag(task, TIF_MEMDIE)) { - if (!force_kill) + if (!oc->force_kill) return OOM_SCAN_ABORT; } if (!task->mm) @@ -280,7 +278,7 @@ enum oom_scan_t oom_scan_process_thread(struct task_struct *task, if (oom_task_origin(task)) return OOM_SCAN_SELECT; - if (task_will_free_mem(task) && !force_kill) + if (task_will_free_mem(task) && !oc->force_kill) return OOM_SCAN_ABORT; return OOM_SCAN_OK; @@ -289,12 +287,9 @@ enum oom_scan_t oom_scan_process_thread(struct task_struct *task, /* * Simple selection loop. We chose the process with the highest * number of 'points'. Returns -1 on scan abort. - * - * (not docbooked, we don't want this one cluttering up the manual) */ -static struct task_struct *select_bad_process(unsigned int *ppoints, - unsigned long totalpages, const nodemask_t *nodemask, - bool force_kill) +static struct task_struct *select_bad_process(struct oom_control *oc, + unsigned int *ppoints, unsigned long totalpages) { struct task_struct *g, *p; struct task_struct *chosen = NULL; @@ -304,8 +299,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints, for_each_process_thread(g, p) { unsigned int points; - switch (oom_scan_process_thread(p, totalpages, nodemask, - force_kill)) { + switch (oom_scan_process_thread(oc, p, totalpages)) { case OOM_SCAN_SELECT: chosen = p; chosen_points = ULONG_MAX; @@ -318,7 +312,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints, case OOM_SCAN_OK: break; }; - points = oom_badness(p, NULL, nodemask, totalpages); + points = oom_badness(p, NULL, oc->nodemask, totalpages); if (!points || points < chosen_points) continue; /* Prefer thread group leaders for display purposes */ @@ -380,13 +374,13 @@ static void dump_tasks(struct mem_cgroup *memcg, const nodemask_t *nodemask) rcu_read_unlock(); } -static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order, - struct mem_cgroup *memcg, const nodemask_t *nodemask) +static void dump_header(struct oom_control *oc, struct task_struct *p, + struct mem_cgroup *memcg) { task_lock(current); pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, " "oom_score_adj=%hd\n", - current->comm, gfp_mask, order, + current->comm, oc->gfp_mask, oc->order, current->signal->oom_score_adj); cpuset_print_task_mems_allowed(current); task_unlock(current); @@ -396,7 +390,7 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order, else show_mem(SHOW_MEM_FILTER_NODES); if (sysctl_oom_dump_tasks) - dump_tasks(memcg, nodemask); + dump_tasks(memcg, oc->nodemask); } /* @@ -487,10 +481,9 @@ void oom_killer_enable(void) * Must be called while holding a reference to p, which will be released upon * returning. */ -void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, +void oom_kill_process(struct oom_control *oc, struct task_struct *p, unsigned int points, unsigned long totalpages, - struct mem_cgroup *memcg, nodemask_t *nodemask, - const char *message) + struct mem_cgroup *memcg, const char *message) { struct task_struct *victim = p; struct task_struct *child; @@ -514,7 +507,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, task_unlock(p); if (__ratelimit(&oom_rs)) - dump_header(p, gfp_mask, order, memcg, nodemask); + dump_header(oc, p, memcg); task_lock(p); pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n", @@ -537,7 +530,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, /* * oom_badness() returns 0 if the thread is unkillable */ - child_points = oom_badness(child, memcg, nodemask, + child_points = oom_badness(child, memcg, oc->nodemask, totalpages); if (child_points > victim_points) { put_task_struct(victim); @@ -600,8 +593,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, /* * Determines whether the kernel must panic because of the panic_on_oom sysctl. */ -void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask, - int order, const nodemask_t *nodemask, +void check_panic_on_oom(struct oom_control *oc, enum oom_constraint constraint, struct mem_cgroup *memcg) { if (likely(!sysctl_panic_on_oom)) @@ -615,7 +607,7 @@ void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask, if (constraint != CONSTRAINT_NONE) return; } - dump_header(NULL, gfp_mask, order, memcg, nodemask); + dump_header(oc, NULL, memcg); panic("Out of memory: %s panic_on_oom is enabled\n", sysctl_panic_on_oom == 2 ? "compulsory" : "system-wide"); } @@ -635,22 +627,16 @@ int unregister_oom_notifier(struct notifier_block *nb) EXPORT_SYMBOL_GPL(unregister_oom_notifier); /** - * __out_of_memory - kill the "best" process when we run out of memory - * @zonelist: zonelist pointer - * @gfp_mask: memory allocation flags - * @order: amount of memory being requested as a power of 2 - * @nodemask: nodemask passed to page allocator - * @force_kill: true if a task must be killed, even if others are exiting + * out_of_memory - kill the "best" process when we run out of memory + * @oc: pointer to struct oom_control * * If we run out of memory, we have the choice between either * killing a random task (bad), letting the system crash (worse) * OR try to be smart about which process to kill. Note that we * don't have to be perfect here, we just have to be good. */ -bool out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, - int order, nodemask_t *nodemask, bool force_kill) +bool out_of_memory(struct oom_control *oc) { - const nodemask_t *mpol_mask; struct task_struct *p; unsigned long totalpages; unsigned long freed = 0; @@ -684,30 +670,29 @@ bool out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, * Check if there were limitations on the allocation (only relevant for * NUMA) that may require different handling. */ - constraint = constrained_alloc(zonelist, gfp_mask, nodemask, - &totalpages); - mpol_mask = (constraint == CONSTRAINT_MEMORY_POLICY) ? nodemask : NULL; - check_panic_on_oom(constraint, gfp_mask, order, mpol_mask, NULL); + constraint = constrained_alloc(oc, &totalpages); + if (constraint != CONSTRAINT_MEMORY_POLICY) + oc->nodemask = NULL; + check_panic_on_oom(oc, constraint, NULL); if (sysctl_oom_kill_allocating_task && current->mm && - !oom_unkillable_task(current, NULL, nodemask) && + !oom_unkillable_task(current, NULL, oc->nodemask) && current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) { get_task_struct(current); - oom_kill_process(current, gfp_mask, order, 0, totalpages, NULL, - nodemask, + oom_kill_process(oc, current, 0, totalpages, NULL, "Out of memory (oom_kill_allocating_task)"); goto out; } - p = select_bad_process(&points, totalpages, mpol_mask, force_kill); + p = select_bad_process(oc, &points, totalpages); /* Found nothing?!?! Either we hang forever, or we panic. */ if (!p) { - dump_header(NULL, gfp_mask, order, NULL, mpol_mask); + dump_header(oc, NULL, NULL); panic("Out of memory and no killable processes...\n"); } if (p != (void *)-1UL) { - oom_kill_process(p, gfp_mask, order, points, totalpages, NULL, - nodemask, "Out of memory"); + oom_kill_process(oc, p, points, totalpages, NULL, + "Out of memory"); killed = 1; } out: @@ -728,13 +713,21 @@ out: */ void pagefault_out_of_memory(void) { + struct oom_control oc = { + .zonelist = NULL, + .nodemask = NULL, + .gfp_mask = 0, + .order = 0, + .force_kill = false, + }; + if (mem_cgroup_oom_synchronize(true)) return; if (!mutex_trylock(&oom_lock)) return; - if (!out_of_memory(NULL, 0, 0, NULL, false)) { + if (!out_of_memory(&oc)) { /* * There shouldn't be any user tasks runnable while the * OOM killer is disabled, so the current task has to -- cgit v1.2.3