Dear RT Folks, I'm pleased to announce the 3.4.41-rt55-feat3 feature release.
Note, I first uploaded -feat2 then realized I didn't add a compile fix by Mike Galbraith, and then created the -feat3 with that fix. You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git branch: v3.4-rt-features Head SHA1: f53b923711ce485f78b8a90843e2072f59be7595 Or to build 3.4.41-rt55-feat3 directly, the following patches should be applied: http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.4.tar.xz http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.4.41.xz http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patch-3.4.41-rt55.patch.xz http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/features/patch-3.4.41-rt55-feat3.patch.xz Broken out patches are available at: http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/features/patches-3.4.41-rt55-feat3.tar.xz Enjoy, -- Steve Changes from 3.4.41-rt55-feat2: --- Mike Galbraith (1): hrtimer: fix hrtimer free zone build bug Steven Rostedt (Red Hat) (1): Linux 3.4.41-rt55-feat3 ---- kernel/hrtimer.c | 2 +- localversion-rt-feat | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --------------------------- Changes from 3.4.41-rt55 -feat1: --- Christoph Lameter (3): FIX [1/2] slub: Do not dereference NULL pointer in node_match FIX [2/2] slub: Tid must be retrieved from the percpu area of the current processor slub: Use correct cpu_slab on dead cpu Steven Rostedt (Red Hat) (1): Linux 3.4.41-rt55-feat2 Thomas Gleixner (2): mm: Enable SLUB for RT slub: Enable irqs for __GFP_WAIT ---- include/linux/slub_def.h | 2 +- init/Kconfig | 1 - localversion-rt-feat | 2 +- mm/slub.c | 144 ++++++++++++++++++++++++++++++++++------------ 4 files changed, 109 insertions(+), 40 deletions(-) --------------------------- diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 2328c04..31d57a2 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1036,7 +1036,7 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, && hrtimer_enqueue_reprogram(timer, new_base)) { if (wakeup -#ifdef CONFIG_PREEMPT_RT_BASE +#if defined(CONFIG_PREEMPT_RT_BASE) && defined(CONFIG_HIGH_RES_TIMERS) /* * Move softirq based timers away from the rbtree in * case it expired already. Otherwise we would have a diff --git a/localversion-rt-feat b/localversion-rt-feat index b349c49..be4ad0c 100644 --- a/localversion-rt-feat +++ b/localversion-rt-feat @@ -1 +1 @@ --feat2 +-feat3 diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index c2f8c8b..f0a69f5 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -55,7 +55,7 @@ struct kmem_cache_cpu { }; struct kmem_cache_node { - spinlock_t list_lock; /* Protect partial list and nr_partial */ + raw_spinlock_t list_lock; /* Protect partial list and nr_partial */ unsigned long nr_partial; struct list_head partial; #ifdef CONFIG_SLUB_DEBUG diff --git a/init/Kconfig b/init/Kconfig index 87afda5..5390b4b 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1266,7 +1266,6 @@ config SLAB config SLUB bool "SLUB (Unqueued Allocator)" - depends on !PREEMPT_RT_FULL help SLUB is a slab allocator that minimizes cache line usage instead of managing queues of cached objects (SLAB approach). diff --git a/localversion-rt-feat b/localversion-rt-feat index 14ee171..b349c49 100644 --- a/localversion-rt-feat +++ b/localversion-rt-feat @@ -1 +1 @@ --feat1 +-feat2 diff --git a/mm/slub.c b/mm/slub.c index 71de9b5..bdb7f3a 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1266,6 +1266,12 @@ static inline void slab_free_hook(struct kmem_cache *s, void *x) {} #endif /* CONFIG_SLUB_DEBUG */ +struct slub_free_list { + raw_spinlock_t lock; + struct list_head list; +}; +static DEFINE_PER_CPU(struct slub_free_list, slub_free_list); + /* * Slab allocation and freeing */ @@ -1287,10 +1293,15 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) struct page *page; struct kmem_cache_order_objects oo = s->oo; gfp_t alloc_gfp; + bool enableirqs; flags &= gfp_allowed_mask; - if (flags & __GFP_WAIT) + enableirqs = (flags & __GFP_WAIT) != 0; +#ifdef CONFIG_PREEMPT_RT_FULL + enableirqs |= system_state == SYSTEM_RUNNING; +#endif + if (enableirqs) local_irq_enable(); flags |= s->allocflags; @@ -1314,7 +1325,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) stat(s, ORDER_FALLBACK); } - if (flags & __GFP_WAIT) + if (enableirqs) local_irq_disable(); if (!page) @@ -1420,6 +1431,16 @@ static void __free_slab(struct kmem_cache *s, struct page *page) __free_pages(page, order); } +static void free_delayed(struct kmem_cache *s, struct list_head *h) +{ + while(!list_empty(h)) { + struct page *page = list_first_entry(h, struct page, lru); + + list_del(&page->lru); + __free_slab(s, page); + } +} + #define need_reserve_slab_rcu \ (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head)) @@ -1454,6 +1475,12 @@ static void free_slab(struct kmem_cache *s, struct page *page) } call_rcu(head, rcu_free_slab); + } else if (irqs_disabled()) { + struct slub_free_list *f = &__get_cpu_var(slub_free_list); + + raw_spin_lock(&f->lock); + list_add(&page->lru, &f->list); + raw_spin_unlock(&f->lock); } else __free_slab(s, page); } @@ -1553,7 +1580,7 @@ static void *get_partial_node(struct kmem_cache *s, if (!n || !n->nr_partial) return NULL; - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); list_for_each_entry_safe(page, page2, &n->partial, lru) { void *t = acquire_slab(s, n, page, object == NULL); int available; @@ -1575,7 +1602,7 @@ static void *get_partial_node(struct kmem_cache *s, break; } - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); return object; } @@ -1824,7 +1851,7 @@ redo: * that acquire_slab() will see a slab page that * is frozen */ - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); } } else { m = M_FULL; @@ -1835,7 +1862,7 @@ redo: * slabs from diagnostic functions will not see * any frozen slabs. */ - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); } } @@ -1870,7 +1897,7 @@ redo: goto redo; if (lock) - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); if (m == M_FREE) { stat(s, DEACTIVATE_EMPTY); @@ -1879,11 +1906,15 @@ redo: } } -/* Unfreeze all the cpu partial slabs */ -static void unfreeze_partials(struct kmem_cache *s) +/* + * Unfreeze all the cpu partial slabs. + * + * This function must be called with interrupt disabled. + */ +static void unfreeze_partials(struct kmem_cache *s, + struct kmem_cache_cpu *c) { struct kmem_cache_node *n = NULL; - struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab); struct page *page, *discard_page = NULL; while ((page = c->partial)) { @@ -1915,10 +1946,10 @@ static void unfreeze_partials(struct kmem_cache *s) m = M_PARTIAL; if (n != n2) { if (n) - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); n = n2; - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); } } @@ -1947,7 +1978,7 @@ static void unfreeze_partials(struct kmem_cache *s) } if (n) - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); while (discard_page) { page = discard_page; @@ -1968,7 +1999,7 @@ static void unfreeze_partials(struct kmem_cache *s) * If we did not find a slot then simply move all the partials to the * per node partial list. */ -int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) +static int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) { struct page *oldpage; int pages; @@ -1983,14 +2014,21 @@ int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) pobjects = oldpage->pobjects; pages = oldpage->pages; if (drain && pobjects > s->cpu_partial) { + LIST_HEAD(tofree); + struct slub_free_list *f; unsigned long flags; /* * partial array is full. Move the existing * set to the per node partial list. */ local_irq_save(flags); - unfreeze_partials(s); + unfreeze_partials(s, this_cpu_ptr(s->cpu_slab)); + f = &__get_cpu_var(slub_free_list); + raw_spin_lock(&f->lock); + list_splice_init(&f->list, &tofree); + raw_spin_unlock(&f->lock); local_irq_restore(flags); + free_delayed(s, &tofree); pobjects = 0; pages = 0; stat(s, CPU_PARTIAL_DRAIN); @@ -2027,7 +2065,7 @@ static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) if (c->page) flush_slab(s, c); - unfreeze_partials(s); + unfreeze_partials(s, c); } } @@ -2048,7 +2086,22 @@ static bool has_cpu_slab(int cpu, void *info) static void flush_all(struct kmem_cache *s) { + LIST_HEAD(tofree); + int cpu; + on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC); + for_each_online_cpu(cpu) { + struct slub_free_list *f; + + if (!has_cpu_slab(cpu, s)) + continue; + + f = &per_cpu(slub_free_list, cpu); + raw_spin_lock_irq(&f->lock); + list_splice_init(&f->list, &tofree); + raw_spin_unlock_irq(&f->lock); + free_delayed(s, &tofree); + } } /* @@ -2058,7 +2111,7 @@ static void flush_all(struct kmem_cache *s) static inline int node_match(struct kmem_cache_cpu *c, int node) { #ifdef CONFIG_NUMA - if (node != NUMA_NO_NODE && c->node != node) + if (!c->page || (node != NUMA_NO_NODE && c->node != node)) return 0; #endif return 1; @@ -2076,10 +2129,10 @@ static unsigned long count_partial(struct kmem_cache_node *n, unsigned long x = 0; struct page *page; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); list_for_each_entry(page, &n->partial, lru) x += get_count(page); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); return x; } @@ -2206,6 +2259,8 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page) static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, unsigned long addr, struct kmem_cache_cpu *c) { + struct slub_free_list *f; + LIST_HEAD(tofree); void **object; unsigned long flags; @@ -2248,7 +2303,13 @@ redo: load_freelist: c->freelist = get_freepointer(s, object); c->tid = next_tid(c->tid); +out: + f = &__get_cpu_var(slub_free_list); + raw_spin_lock(&f->lock); + list_splice_init(&f->list, &tofree); + raw_spin_unlock(&f->lock); local_irq_restore(flags); + free_delayed(s, &tofree); return object; new_slab: @@ -2273,8 +2334,7 @@ new_slab: if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit()) slab_out_of_memory(s, gfpflags, node); - local_irq_restore(flags); - return NULL; + goto out; } } @@ -2288,8 +2348,7 @@ new_slab: c->freelist = get_freepointer(s, object); deactivate_slab(s, c); c->node = NUMA_NO_NODE; - local_irq_restore(flags); - return object; + goto out; } /* @@ -2313,13 +2372,18 @@ static __always_inline void *slab_alloc(struct kmem_cache *s, return NULL; redo: - /* * Must read kmem_cache cpu data via this cpu ptr. Preemption is * enabled. We may switch back and forth between cpus while * reading from one cpu area. That does not matter as long * as we end up on the original cpu again when doing the cmpxchg. + * + * Preemption is disabled for the retrieval of the tid because that + * must occur from the current processor. We cannot allow rescheduling + * on a different processor between the determination of the pointer + * and the retrieval of the tid. */ + preempt_disable(); c = __this_cpu_ptr(s->cpu_slab); /* @@ -2329,7 +2393,7 @@ redo: * linked list in between. */ tid = c->tid; - barrier(); + preempt_enable(); object = c->freelist; if (unlikely(!object || !node_match(c, node))) @@ -2479,7 +2543,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page, * Otherwise the list_lock will synchronize with * other processors updating the list of slabs. */ - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); } } @@ -2529,7 +2593,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page, stat(s, FREE_ADD_PARTIAL); } } - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); return; slab_empty: @@ -2543,7 +2607,7 @@ slab_empty: /* Slab must be on the full list */ remove_full(s, page); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); stat(s, FREE_SLAB); discard_slab(s, page); } @@ -2575,10 +2639,11 @@ redo: * data is retrieved via this pointer. If we are on the same cpu * during the cmpxchg then the free will succedd. */ + preempt_disable(); c = __this_cpu_ptr(s->cpu_slab); tid = c->tid; - barrier(); + preempt_enable(); if (likely(page == c->page)) { set_freepointer(s, object, c->freelist); @@ -2772,7 +2837,7 @@ static void init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s) { n->nr_partial = 0; - spin_lock_init(&n->list_lock); + raw_spin_lock_init(&n->list_lock); INIT_LIST_HEAD(&n->partial); #ifdef CONFIG_SLUB_DEBUG atomic_long_set(&n->nr_slabs, 0); @@ -3515,7 +3580,7 @@ int kmem_cache_shrink(struct kmem_cache *s) for (i = 0; i < objects; i++) INIT_LIST_HEAD(slabs_by_inuse + i); - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); /* * Build lists indexed by the items in use in each slab. @@ -3536,7 +3601,7 @@ int kmem_cache_shrink(struct kmem_cache *s) for (i = objects - 1; i > 0; i--) list_splice(slabs_by_inuse + i, n->partial.prev); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); /* Release empty slabs */ list_for_each_entry_safe(page, t, slabs_by_inuse, lru) @@ -3702,10 +3767,15 @@ void __init kmem_cache_init(void) int i; int caches = 0; struct kmem_cache *temp_kmem_cache; - int order; + int order, cpu; struct kmem_cache *temp_kmem_cache_node; unsigned long kmalloc_size; + for_each_possible_cpu(cpu) { + raw_spin_lock_init(&per_cpu(slub_free_list, cpu).lock); + INIT_LIST_HEAD(&per_cpu(slub_free_list, cpu).list); + } + if (debug_guardpage_minorder()) slub_max_order = 0; @@ -4129,7 +4199,7 @@ static int validate_slab_node(struct kmem_cache *s, struct page *page; unsigned long flags; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); list_for_each_entry(page, &n->partial, lru) { validate_slab_slab(s, page, map); @@ -4152,7 +4222,7 @@ static int validate_slab_node(struct kmem_cache *s, atomic_long_read(&n->nr_slabs)); out: - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); return count; } @@ -4342,12 +4412,12 @@ static int list_locations(struct kmem_cache *s, char *buf, if (!atomic_long_read(&n->nr_slabs)) continue; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); list_for_each_entry(page, &n->partial, lru) process_slab(&t, s, page, alloc, map); list_for_each_entry(page, &n->full, lru) process_slab(&t, s, page, alloc, map); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); } for (i = 0; i < t.count; i++) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
