diff options
Diffstat (limited to 'net/core/flow.c')
-rw-r--r-- | net/core/flow.c | 55 |
1 files changed, 45 insertions, 10 deletions
diff --git a/net/core/flow.c b/net/core/flow.c index 43f7495..7102f16 100644 --- a/net/core/flow.c +++ b/net/core/flow.c @@ -132,14 +132,14 @@ static void __flow_cache_shrink(struct flow_cache *fc, int shrink_to) { struct flow_cache_entry *fle; - struct hlist_node *entry, *tmp; + struct hlist_node *tmp; LIST_HEAD(gc_list); int i, deleted = 0; for (i = 0; i < flow_cache_hash_size(fc); i++) { int saved = 0; - hlist_for_each_entry_safe(fle, entry, tmp, + hlist_for_each_entry_safe(fle, tmp, &fcp->hash_table[i], u.hlist) { if (saved < shrink_to && flow_entry_valid(fle)) { @@ -211,7 +211,6 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir, struct flow_cache *fc = &flow_cache_global; struct flow_cache_percpu *fcp; struct flow_cache_entry *fle, *tfle; - struct hlist_node *entry; struct flow_cache_object *flo; size_t keysize; unsigned int hash; @@ -235,7 +234,7 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir, flow_new_hash_rnd(fc, fcp); hash = flow_hash_code(fc, fcp, key, keysize); - hlist_for_each_entry(tfle, entry, &fcp->hash_table[hash], u.hlist) { + hlist_for_each_entry(tfle, &fcp->hash_table[hash], u.hlist) { if (tfle->net == net && tfle->family == family && tfle->dir == dir && @@ -301,13 +300,13 @@ static void flow_cache_flush_tasklet(unsigned long data) struct flow_cache *fc = info->cache; struct flow_cache_percpu *fcp; struct flow_cache_entry *fle; - struct hlist_node *entry, *tmp; + struct hlist_node *tmp; LIST_HEAD(gc_list); int i, deleted = 0; fcp = this_cpu_ptr(fc->percpu); for (i = 0; i < flow_cache_hash_size(fc); i++) { - hlist_for_each_entry_safe(fle, entry, tmp, + hlist_for_each_entry_safe(fle, tmp, &fcp->hash_table[i], u.hlist) { if (flow_entry_valid(fle)) continue; @@ -324,12 +323,30 @@ static void flow_cache_flush_tasklet(unsigned long data) complete(&info->completion); } +/* + * Return whether a cpu needs flushing. Conservatively, we assume + * the presence of any entries means the core may require flushing, + * since the flow_cache_ops.check() function may assume it's running + * on the same core as the per-cpu cache component. + */ +static int flow_cache_percpu_empty(struct flow_cache *fc, int cpu) +{ + struct flow_cache_percpu *fcp; + int i; + + fcp = per_cpu_ptr(fc->percpu, cpu); + for (i = 0; i < flow_cache_hash_size(fc); i++) + if (!hlist_empty(&fcp->hash_table[i])) + return 0; + return 1; +} + static void flow_cache_flush_per_cpu(void *data) { struct flow_flush_info *info = data; struct tasklet_struct *tasklet; - tasklet = this_cpu_ptr(&info->cache->percpu->flush_tasklet); + tasklet = &this_cpu_ptr(info->cache->percpu)->flush_tasklet; tasklet->data = (unsigned long)info; tasklet_schedule(tasklet); } @@ -338,22 +355,40 @@ void flow_cache_flush(void) { struct flow_flush_info info; static DEFINE_MUTEX(flow_flush_sem); + cpumask_var_t mask; + int i, self; + + /* Track which cpus need flushing to avoid disturbing all cores. */ + if (!alloc_cpumask_var(&mask, GFP_KERNEL)) + return; + cpumask_clear(mask); /* Don't want cpus going down or up during this. */ get_online_cpus(); mutex_lock(&flow_flush_sem); info.cache = &flow_cache_global; - atomic_set(&info.cpuleft, num_online_cpus()); + for_each_online_cpu(i) + if (!flow_cache_percpu_empty(info.cache, i)) + cpumask_set_cpu(i, mask); + atomic_set(&info.cpuleft, cpumask_weight(mask)); + if (atomic_read(&info.cpuleft) == 0) + goto done; + init_completion(&info.completion); local_bh_disable(); - smp_call_function(flow_cache_flush_per_cpu, &info, 0); - flow_cache_flush_tasklet((unsigned long)&info); + self = cpumask_test_and_clear_cpu(smp_processor_id(), mask); + on_each_cpu_mask(mask, flow_cache_flush_per_cpu, &info, 0); + if (self) + flow_cache_flush_tasklet((unsigned long)&info); local_bh_enable(); wait_for_completion(&info.completion); + +done: mutex_unlock(&flow_flush_sem); put_online_cpus(); + free_cpumask_var(mask); } static void flow_cache_flush_task(struct work_struct *work) |