Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750873AbWCOLHT (ORCPT ); Wed, 15 Mar 2006 06:07:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751379AbWCOLHT (ORCPT ); Wed, 15 Mar 2006 06:07:19 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:46748 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1750873AbWCOLHR (ORCPT ); Wed, 15 Mar 2006 06:07:17 -0500 Date: Wed, 15 Mar 2006 12:04:58 +0100 From: Ingo Molnar To: Jan Altenberg Cc: karsten wiese , Rui Nuno Capela , linux-kernel@vger.kernel.org Subject: Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues) Message-ID: <20060315110458.GA15012@elte.hu> References: <36944.195.245.190.93.1141734835.squirrel@www.rncbc.org> <20060314231344.44688.qmail@web26506.mail.ukl.yahoo.com> <20060315093122.GA1682@elte.hu> <4417EA34.20802@tglx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4417EA34.20802@tglx.de> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.5 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] 0.8 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9862 Lines: 328 * Jan Altenberg wrote: > > a better fix would be the one below - it still does the call on the > > current CPU, and skips other CPUs (on SMP). Does this solve the problem > > on your box too? > > Tested in all a hurry and it seems to work for me too. a full fix is below: this re-enables the full SLAB related smp-call functionality on PREEMPT_RT too (without any hackery), and fixes a couple of rt-NUMA bugs as well. Ingo Index: linux-rt.q/mm/slab.c =================================================================== --- linux-rt.q.orig/mm/slab.c +++ linux-rt.q/mm/slab.c @@ -147,9 +147,9 @@ # define slab_spin_unlock_irqrestore(lock, flags, cpu) \ do { spin_unlock_irqrestore(lock, flags); } while (0) #else -DEFINE_PER_CPU_LOCKED(int, slab_locks) = { 0, }; -# define slab_irq_disable(cpu) get_cpu_var_locked(slab_locks, &(cpu)) -# define slab_irq_enable(cpu) put_cpu_var_locked(slab_locks, cpu) +DEFINE_PER_CPU_LOCKED(int, slab_irq_locks) = { 0, }; +# define slab_irq_disable(cpu) get_cpu_var_locked(slab_irq_locks, &(cpu)) +# define slab_irq_enable(cpu) put_cpu_var_locked(slab_irq_locks, cpu) # define slab_irq_save(flags, cpu) \ do { slab_irq_disable(cpu); (void) (flags); } while (0) # define slab_irq_restore(flags, cpu) \ @@ -989,7 +989,8 @@ static void __drain_alien_cache(struct k /* * Called from cache_reap() to regularly drain alien caches round robin. */ -static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) +static void +reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3, int *this_cpu) { int node = __get_cpu_var(reap_node); @@ -997,7 +998,7 @@ static void reap_alien(struct kmem_cache struct array_cache *ac = l3->alien[node]; if (ac && ac->avail) { spin_lock_irq(&ac->lock); - __drain_alien_cache(cachep, ac, node); + __drain_alien_cache(cachep, ac, node, this_cpu); spin_unlock_irq(&ac->lock); } } @@ -1022,7 +1023,7 @@ static void drain_alien_cache(struct kme #else #define drain_alien_cache(cachep, alien) do { } while (0) -#define reap_alien(cachep, l3) do { } while (0) +#define reap_alien(cachep, l3, this_cpu) do { } while (0) static inline struct array_cache **alloc_alien_cache(int node, int limit) { @@ -2164,14 +2165,6 @@ static void check_irq_on(void) #endif } -static void check_spinlock_acquired(struct kmem_cache *cachep) -{ -#ifdef CONFIG_SMP - check_irq_off(); - assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock); -#endif -} - static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) { #ifdef CONFIG_SMP @@ -2183,39 +2176,57 @@ static void check_spinlock_acquired_node #else #define check_irq_off() do { } while(0) #define check_irq_on() do { } while(0) -#define check_spinlock_acquired(x) do { } while(0) #define check_spinlock_acquired_node(x, y) do { } while(0) #endif +#ifdef CONFIG_PREEMPT_RT +/* + * execute func() for all CPUs. On PREEMPT_RT we dont actually have + * to run on the remote CPUs - we only have to take their CPU-locks. + * (This is a rare operation, so cacheline bouncing is not an issue.) + */ +static void +smp_call_function_all_cpus(void (*func)(void *arg, int this_cpu), void *arg) +{ + unsigned int i; + + check_irq_on(); + for_each_online_cpu(i) { + spin_lock(&__get_cpu_lock(slab_irq_locks, i)); + func(arg, i); + spin_unlock(&__get_cpu_lock(slab_irq_locks, i)); + } +} +#else /* * Waits for all CPUs to execute func(). */ static void smp_call_function_all_cpus(void (*func)(void *arg), void *arg) { - unsigned long flags; + unsigned int this_cpu; check_irq_on(); preempt_disable(); - slab_irq_disable(flags); + slab_irq_disable(this_cpu); func(arg); - slab_irq_enable(flags); + slab_irq_enable(this_cpu); if (smp_call_function(func, arg, 1, 1)) BUG(); preempt_enable(); } +#endif static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac, int force, int node); -static void do_drain(void *arg) +static void __do_drain(void *arg, int this_cpu) { struct kmem_cache *cachep = (struct kmem_cache *) arg; + int node = cpu_to_node(this_cpu); struct array_cache *ac; - int node = numa_node_id(); - int this_cpu = smp_processor_id(); check_irq_off(); ac = cpu_cache_get(cachep, this_cpu); @@ -2225,14 +2236,25 @@ static void do_drain(void *arg) ac->avail = 0; } +#ifdef CONFIG_PREEMPT_RT +static void do_drain(void *arg, int this_cpu) +{ + __do_drain(arg, this_cpu); +} +#else +static void do_drain(void *arg) +{ + __do_drain(arg, smp_processor_id()); +} +#endif + static void drain_cpu_caches(struct kmem_cache *cachep) { struct kmem_list3 *l3; int this_cpu; int node; -// FIXME: -// smp_call_function_all_cpus(do_drain, cachep); + smp_call_function_all_cpus(do_drain, cachep); check_irq_on(); for_each_online_node(node) { l3 = cachep->nodelists[node]; @@ -2759,7 +2781,7 @@ cache_alloc_refill(struct kmem_cache *ca */ batchcount = BATCHREFILL_LIMIT; } - l3 = cachep->nodelists[numa_node_id()]; + l3 = cachep->nodelists[cpu_to_node(*this_cpu)]; BUG_ON(ac->avail > 0 || !l3); spin_lock(&l3->list_lock); @@ -2792,14 +2814,14 @@ cache_alloc_refill(struct kmem_cache *ca slabp = list_entry(entry, struct slab, list); check_slabp(cachep, slabp); - check_spinlock_acquired(cachep); + check_spinlock_acquired_node(cachep, cpu_to_node(*this_cpu)); while (slabp->inuse < cachep->num && batchcount--) { STATS_INC_ALLOCED(cachep); STATS_INC_ACTIVE(cachep); STATS_SET_HIGH(cachep); ac->entry[ac->avail++] = slab_get_obj(cachep, slabp, - numa_node_id()); + cpu_to_node(*this_cpu)); } check_slabp(cachep, slabp); @@ -2818,7 +2840,7 @@ cache_alloc_refill(struct kmem_cache *ca if (unlikely(!ac->avail)) { int x; - x = cache_grow(cachep, flags, numa_node_id(), this_cpu); + x = cache_grow(cachep, flags, cpu_to_node(*this_cpu), this_cpu); // cache_grow can reenable interrupts, then ac could change. ac = cpu_cache_get(cachep, *this_cpu); @@ -2901,7 +2923,7 @@ ____cache_alloc(struct kmem_cache *cache if (unlikely(current->mempolicy && !in_interrupt())) { int nid = slab_node(current->mempolicy); - if (nid != numa_node_id()) + if (nid != cpu_to_node(*this_cpu)) return __cache_alloc_node(cachep, flags, nid, this_cpu); } #endif @@ -3043,11 +3065,12 @@ static void free_block(struct kmem_cache } } -static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac, int *this_cpu) +static void +cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac, int *this_cpu) { int batchcount; struct kmem_list3 *l3; - int node = numa_node_id(); + int node = cpu_to_node(*this_cpu); batchcount = ac->batchcount; #if DEBUG @@ -3117,11 +3140,11 @@ __cache_free(struct kmem_cache *cachep, { struct slab *slabp; slabp = virt_to_slab(objp); - if (unlikely(slabp->nodeid != numa_node_id())) { + if (unlikely(slabp->nodeid != cpu_to_node(*this_cpu))) { struct array_cache *alien = NULL; int nodeid = slabp->nodeid; struct kmem_list3 *l3 = - cachep->nodelists[numa_node_id()]; + cachep->nodelists[cpu_to_node(*this_cpu)]; STATS_INC_NODEFREES(cachep); if (l3->alien && l3->alien[nodeid]) { @@ -3231,7 +3254,7 @@ void *kmem_cache_alloc_node(struct kmem_ cache_alloc_debugcheck_before(cachep, flags); slab_irq_save(save_flags, this_cpu); - if (nodeid == -1 || nodeid == numa_node_id() || + if (nodeid == -1 || nodeid == cpu_to_node(this_cpu) || !cachep->nodelists[nodeid]) ptr = ____cache_alloc(cachep, flags, &this_cpu); else @@ -3508,18 +3531,31 @@ struct ccupdate_struct { struct array_cache *new[NR_CPUS]; }; -static void do_ccupdate_local(void *info) +static void __do_ccupdate_local(void *info, int this_cpu) { struct ccupdate_struct *new = (struct ccupdate_struct *)info; struct array_cache *old; check_irq_off(); - old = cpu_cache_get(new->cachep, smp_processor_id()); + old = cpu_cache_get(new->cachep, this_cpu); - new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; - new->new[smp_processor_id()] = old; + new->cachep->array[this_cpu] = new->new[this_cpu]; + new->new[this_cpu] = old; } +#ifdef CONFIG_PREEMPT_RT +static void do_ccupdate_local(void *arg, int this_cpu) +{ + __do_ccupdate_local(arg, this_cpu); +} +#else +static void do_ccupdate_local(void *info) +{ + __do_ccupdate_local(arg, smp_processor_id()); +} +#endif + + static int do_tune_cpucache(struct kmem_cache *cachep, int limit, int batchcount, int shared) { @@ -3654,9 +3690,9 @@ static void drain_array_locked(struct km */ static void cache_reap(void *unused) { + int this_cpu = raw_smp_processor_id(); struct list_head *walk; struct kmem_list3 *l3; - int this_cpu; if (!mutex_trylock(&cache_chain_mutex)) { /* Give up. Setup the next iteration. */ @@ -3678,12 +3714,13 @@ static void cache_reap(void *unused) check_irq_on(); - l3 = searchp->nodelists[numa_node_id()]; - reap_alien(searchp, l3); + l3 = searchp->nodelists[cpu_to_node(this_cpu)]; + reap_alien(searchp, l3, &this_cpu); + slab_spin_lock_irq(&l3->list_lock, this_cpu); drain_array_locked(searchp, cpu_cache_get(searchp, this_cpu), 0, - numa_node_id()); + cpu_to_node(this_cpu)); if (time_after(l3->next_reap, jiffies)) goto next_unlock; @@ -3692,7 +3729,7 @@ static void cache_reap(void *unused) if (l3->shared) drain_array_locked(searchp, l3->shared, 0, - numa_node_id()); + cpu_to_node(this_cpu)); if (l3->free_touched) { l3->free_touched = 0; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/