Return-Path: Received: from mail-pd0-f174.google.com ([209.85.192.174]:32818 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752127AbbG3NCP (ORCPT ); Thu, 30 Jul 2015 09:02:15 -0400 Message-ID: <55BA203B.908@gmail.com> Date: Thu, 30 Jul 2015 21:01:47 +0800 From: Kinglong Mee MIME-Version: 1.0 To: "J. Bruce Fields" , NeilBrown CC: Al Viro , "linux-nfs@vger.kernel.org" , linux-fsdevel@vger.kernel.org, Trond Myklebust , kinglongmee@gmail.com Subject: Re: [PATCH 7/9 v8] sunrpc: Switch to using hash list instead single list References: <55B5A012.1030006@gmail.com> <55B5A117.1020902@gmail.com> <20150729121939.517008f4@noble> <20150729195151.GD21949@fieldses.org> In-Reply-To: <20150729195151.GD21949@fieldses.org> Content-Type: text/plain; charset=windows-1252 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 7/30/2015 03:51, J. Bruce Fields wrote: > On Wed, Jul 29, 2015 at 12:19:39PM +1000, NeilBrown wrote: >> On Mon, 27 Jul 2015 11:10:15 +0800 Kinglong Mee >> wrote: >> >>> Switch using list_head for cache_head in cache_detail, >>> it is useful of remove an cache_head entry directly from cache_detail. >>> >>> v8, using hash list, not head list >>> >>> Signed-off-by: Kinglong Mee >> >> Reviewed-by: NeilBrown > > Thanks, applying this and previous 2 patches. Thanks, I see them in your tree. I will not include those 3 patches in the next version. thanks, Kinglong Mee > > --b. > >> >> Thanks, >> NeilBrown >> >>> --- >>> include/linux/sunrpc/cache.h | 4 +-- >>> net/sunrpc/cache.c | 60 +++++++++++++++++++++++--------------------- >>> 2 files changed, 33 insertions(+), 31 deletions(-) >>> >>> diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h >>> index 04ee5a2..03d3b4c 100644 >>> --- a/include/linux/sunrpc/cache.h >>> +++ b/include/linux/sunrpc/cache.h >>> @@ -46,7 +46,7 @@ >>> * >>> */ >>> struct cache_head { >>> - struct cache_head * next; >>> + struct hlist_node cache_list; >>> time_t expiry_time; /* After time time, don't use the data */ >>> time_t last_refresh; /* If CACHE_PENDING, this is when upcall >>> * was sent, else this is when update was received >>> @@ -73,7 +73,7 @@ struct cache_detail_pipefs { >>> struct cache_detail { >>> struct module * owner; >>> int hash_size; >>> - struct cache_head ** hash_table; >>> + struct hlist_head * hash_table; >>> rwlock_t hash_lock; >>> >>> atomic_t inuse; /* active user-space update or lookup */ >>> diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c >>> index 673c2fa..4a2340a 100644 >>> --- a/net/sunrpc/cache.c >>> +++ b/net/sunrpc/cache.c >>> @@ -44,7 +44,7 @@ static void cache_revisit_request(struct cache_head *item); >>> static void cache_init(struct cache_head *h) >>> { >>> time_t now = seconds_since_boot(); >>> - h->next = NULL; >>> + INIT_HLIST_NODE(&h->cache_list); >>> h->flags = 0; >>> kref_init(&h->ref); >>> h->expiry_time = now + CACHE_NEW_EXPIRY; >>> @@ -54,15 +54,14 @@ static void cache_init(struct cache_head *h) >>> struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, >>> struct cache_head *key, int hash) >>> { >>> - struct cache_head **head, **hp; >>> - struct cache_head *new = NULL, *freeme = NULL; >>> + struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL; >>> + struct hlist_head *head; >>> >>> head = &detail->hash_table[hash]; >>> >>> read_lock(&detail->hash_lock); >>> >>> - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { >>> - struct cache_head *tmp = *hp; >>> + hlist_for_each_entry(tmp, head, cache_list) { >>> if (detail->match(tmp, key)) { >>> if (cache_is_expired(detail, tmp)) >>> /* This entry is expired, we will discard it. */ >>> @@ -88,12 +87,10 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, >>> write_lock(&detail->hash_lock); >>> >>> /* check if entry appeared while we slept */ >>> - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { >>> - struct cache_head *tmp = *hp; >>> + hlist_for_each_entry(tmp, head, cache_list) { >>> if (detail->match(tmp, key)) { >>> if (cache_is_expired(detail, tmp)) { >>> - *hp = tmp->next; >>> - tmp->next = NULL; >>> + hlist_del_init(&tmp->cache_list); >>> detail->entries --; >>> freeme = tmp; >>> break; >>> @@ -104,8 +101,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, >>> return tmp; >>> } >>> } >>> - new->next = *head; >>> - *head = new; >>> + >>> + hlist_add_head(&new->cache_list, head); >>> detail->entries++; >>> cache_get(new); >>> write_unlock(&detail->hash_lock); >>> @@ -143,7 +140,6 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, >>> * If 'old' is not VALID, we update it directly, >>> * otherwise we need to replace it >>> */ >>> - struct cache_head **head; >>> struct cache_head *tmp; >>> >>> if (!test_bit(CACHE_VALID, &old->flags)) { >>> @@ -168,15 +164,13 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, >>> } >>> cache_init(tmp); >>> detail->init(tmp, old); >>> - head = &detail->hash_table[hash]; >>> >>> write_lock(&detail->hash_lock); >>> if (test_bit(CACHE_NEGATIVE, &new->flags)) >>> set_bit(CACHE_NEGATIVE, &tmp->flags); >>> else >>> detail->update(tmp, new); >>> - tmp->next = *head; >>> - *head = tmp; >>> + hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]); >>> detail->entries++; >>> cache_get(tmp); >>> cache_fresh_locked(tmp, new->expiry_time); >>> @@ -416,28 +410,29 @@ static int cache_clean(void) >>> /* find a non-empty bucket in the table */ >>> while (current_detail && >>> current_index < current_detail->hash_size && >>> - current_detail->hash_table[current_index] == NULL) >>> + hlist_empty(¤t_detail->hash_table[current_index])) >>> current_index++; >>> >>> /* find a cleanable entry in the bucket and clean it, or set to next bucket */ >>> >>> if (current_detail && current_index < current_detail->hash_size) { >>> - struct cache_head *ch, **cp; >>> + struct cache_head *ch = NULL; >>> struct cache_detail *d; >>> + struct hlist_head *head; >>> + struct hlist_node *tmp; >>> >>> write_lock(¤t_detail->hash_lock); >>> >>> /* Ok, now to clean this strand */ >>> >>> - cp = & current_detail->hash_table[current_index]; >>> - for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) { >>> + head = ¤t_detail->hash_table[current_index]; >>> + hlist_for_each_entry_safe(ch, tmp, head, cache_list) { >>> if (current_detail->nextcheck > ch->expiry_time) >>> current_detail->nextcheck = ch->expiry_time+1; >>> if (!cache_is_expired(current_detail, ch)) >>> continue; >>> >>> - *cp = ch->next; >>> - ch->next = NULL; >>> + hlist_del_init(&ch->cache_list); >>> current_detail->entries--; >>> rv = 1; >>> break; >>> @@ -1284,7 +1279,7 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) >>> hash = n >> 32; >>> entry = n & ((1LL<<32) - 1); >>> >>> - for (ch=cd->hash_table[hash]; ch; ch=ch->next) >>> + hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list) >>> if (!entry--) >>> return ch; >>> n &= ~((1LL<<32) - 1); >>> @@ -1292,11 +1287,12 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) >>> hash++; >>> n += 1LL<<32; >>> } while(hash < cd->hash_size && >>> - cd->hash_table[hash]==NULL); >>> + hlist_empty(&cd->hash_table[hash])); >>> if (hash >= cd->hash_size) >>> return NULL; >>> *pos = n+1; >>> - return cd->hash_table[hash]; >>> + return hlist_entry_safe(cd->hash_table[hash].first, >>> + struct cache_head, cache_list); >>> } >>> EXPORT_SYMBOL_GPL(cache_seq_start); >>> >>> @@ -1308,23 +1304,25 @@ void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) >>> >>> if (p == SEQ_START_TOKEN) >>> hash = 0; >>> - else if (ch->next == NULL) { >>> + else if (ch->cache_list.next == NULL) { >>> hash++; >>> *pos += 1LL<<32; >>> } else { >>> ++*pos; >>> - return ch->next; >>> + return hlist_entry_safe(ch->cache_list.next, >>> + struct cache_head, cache_list); >>> } >>> *pos &= ~((1LL<<32) - 1); >>> while (hash < cd->hash_size && >>> - cd->hash_table[hash] == NULL) { >>> + hlist_empty(&cd->hash_table[hash])) { >>> hash++; >>> *pos += 1LL<<32; >>> } >>> if (hash >= cd->hash_size) >>> return NULL; >>> ++*pos; >>> - return cd->hash_table[hash]; >>> + return hlist_entry_safe(cd->hash_table[hash].first, >>> + struct cache_head, cache_list); >>> } >>> EXPORT_SYMBOL_GPL(cache_seq_next); >>> >>> @@ -1666,17 +1664,21 @@ EXPORT_SYMBOL_GPL(cache_unregister_net); >>> struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net) >>> { >>> struct cache_detail *cd; >>> + int i; >>> >>> cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); >>> if (cd == NULL) >>> return ERR_PTR(-ENOMEM); >>> >>> - cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *), >>> + cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head), >>> GFP_KERNEL); >>> if (cd->hash_table == NULL) { >>> kfree(cd); >>> return ERR_PTR(-ENOMEM); >>> } >>> + >>> + for (i = 0; i < cd->hash_size; i++) >>> + INIT_HLIST_HEAD(&cd->hash_table[i]); >>> cd->net = net; >>> return cd; >>> } >