| Message ID | 55A11112.8080502@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> + struct list_head * hash_table; For hash lists it might be useful to use a hlist_head structure, as that avoids bloating the actual hash table while still allowing easy removal of an entry. > - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { > - struct cache_head *tmp = *hp; > + list_for_each_safe(pos, tpos, head) { > + tmp = list_entry(pos, struct cache_head, cache_list); Please use the _entry iteration macros that consolidate these two. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, 11 Jul 2015 20:50:26 +0800 Kinglong Mee <kinglongmee@gmail.com> wrote: > Switch using list_head for cache_head in cache_detail, > it is useful of remove an cache_head entry directly from cache_detail. > > v7, same as v6. > > Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> > --- > include/linux/sunrpc/cache.h | 4 +-- > net/sunrpc/cache.c | 74 ++++++++++++++++++++++++-------------------- > 2 files changed, 43 insertions(+), 35 deletions(-) > > diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h > index 04ee5a2..ecc0ff6 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 list_head 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 list_head * hash_table; > rwlock_t hash_lock; Given that these lists are chains in a hash table, it would make more sense to use hlist_head rather than list_head. They are designed for exactly that purpose - and are smaller. Actually, I'd really like to see hlist_bl_head used - so there was one bit-spin-lock per chain, and use RCU for protecting searches. However that would have to be left for later - no point delaying this patch set for some minor performance gains. But as you need to change this, I think it would be best to change to hlist_head. By the way, I see lots of nice clean-ups in this series. Thanks! NeilBrown > > atomic_t inuse; /* active user-space update or lookup */ > diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c > index 673c2fa..ad2155c 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_LIST_HEAD(&h->cache_list); > h->flags = 0; > kref_init(&h->ref); > h->expiry_time = now + CACHE_NEW_EXPIRY; > @@ -54,15 +54,16 @@ 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 *tmp; > + struct list_head *head, *pos, *tpos; > > head = &detail->hash_table[hash]; > > read_lock(&detail->hash_lock); > > - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { > - struct cache_head *tmp = *hp; > + list_for_each_safe(pos, tpos, head) { > + tmp = list_entry(pos, struct cache_head, cache_list); > if (detail->match(tmp, key)) { > if (cache_is_expired(detail, tmp)) > /* This entry is expired, we will discard it. */ > @@ -88,12 +89,11 @@ 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; > + list_for_each_safe(pos, tpos, head) { > + tmp = list_entry(pos, struct cache_head, cache_list); > if (detail->match(tmp, key)) { > if (cache_is_expired(detail, tmp)) { > - *hp = tmp->next; > - tmp->next = NULL; > + list_del_init(&tmp->cache_list); > detail->entries --; > freeme = tmp; > break; > @@ -104,8 +104,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, > return tmp; > } > } > - new->next = *head; > - *head = new; > + > + list_add(&new->cache_list, head); > detail->entries++; > cache_get(new); > write_unlock(&detail->hash_lock); > @@ -143,7 +143,6 @@ 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 +167,13 @@ 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; > + list_add(&tmp->cache_list, &detail->hash_table[hash]); > detail->entries++; > cache_get(tmp); > cache_fresh_locked(tmp, new->expiry_time); > @@ -416,42 +413,44 @@ 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) > + list_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, *putme = NULL; > + struct list_head *head, *pos, *tpos; > struct cache_detail *d; > > 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]; > + list_for_each_safe(pos, tpos, head) { > + ch = list_entry(pos, struct cache_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; > + list_del_init(pos); > current_detail->entries--; > + putme = ch; > rv = 1; > break; > } > > write_unlock(¤t_detail->hash_lock); > d = current_detail; > - if (!ch) > + if (!putme) > current_index ++; > spin_unlock(&cache_list_lock); > - if (ch) { > - set_bit(CACHE_CLEANED, &ch->flags); > - cache_fresh_unlocked(ch, d); > - cache_put(ch, d); > + if (putme) { > + set_bit(CACHE_CLEANED, &putme->flags); > + cache_fresh_unlocked(putme, d); > + cache_put(putme, d); > } > } else > spin_unlock(&cache_list_lock); > @@ -1277,6 +1276,7 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) > unsigned int hash, entry; > struct cache_head *ch; > struct cache_detail *cd = m->private; > + struct list_head *ptr, *tptr; > > read_lock(&cd->hash_lock); > if (!n--) > @@ -1284,19 +1284,22 @@ 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) > + list_for_each_safe(ptr, tptr, &cd->hash_table[hash]) { > + ch = list_entry(ptr, struct cache_head, cache_list); > if (!entry--) > return ch; > + } > n &= ~((1LL<<32) - 1); > do { > hash++; > n += 1LL<<32; > } while(hash < cd->hash_size && > - cd->hash_table[hash]==NULL); > + list_empty(&cd->hash_table[hash])); > if (hash >= cd->hash_size) > return NULL; > *pos = n+1; > - return cd->hash_table[hash]; > + return list_first_entry_or_null(&cd->hash_table[hash], > + struct cache_head, cache_list); > } > EXPORT_SYMBOL_GPL(cache_seq_start); > > @@ -1308,23 +1311,24 @@ 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 (list_is_last(&ch->cache_list, &cd->hash_table[hash])) { > hash++; > *pos += 1LL<<32; > } else { > ++*pos; > - return ch->next; > + return list_next_entry(ch, cache_list); > } > *pos &= ~((1LL<<32) - 1); > while (hash < cd->hash_size && > - cd->hash_table[hash] == NULL) { > + list_empty(&cd->hash_table[hash])) { > hash++; > *pos += 1LL<<32; > } > if (hash >= cd->hash_size) > return NULL; > ++*pos; > - return cd->hash_table[hash]; > + return list_first_entry_or_null(&cd->hash_table[hash], > + struct cache_head, cache_list); > } > EXPORT_SYMBOL_GPL(cache_seq_next); > > @@ -1666,17 +1670,21 @@ 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 list_head), > GFP_KERNEL); > if (cd->hash_table == NULL) { > kfree(cd); > return ERR_PTR(-ENOMEM); > } > + > + for (i = 0; i < cd->hash_size; i++) > + INIT_LIST_HEAD(&cd->hash_table[i]); > cd->net = net; > return cd; > } -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 7/13/2015 09:30, NeilBrown wrote: > On Sat, 11 Jul 2015 20:50:26 +0800 Kinglong Mee <kinglongmee@gmail.com> > wrote: > >> Switch using list_head for cache_head in cache_detail, >> it is useful of remove an cache_head entry directly from cache_detail. >> >> v7, same as v6. >> >> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> >> --- >> include/linux/sunrpc/cache.h | 4 +-- >> net/sunrpc/cache.c | 74 ++++++++++++++++++++++++-------------------- >> 2 files changed, 43 insertions(+), 35 deletions(-) >> >> diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h >> index 04ee5a2..ecc0ff6 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 list_head 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 list_head * hash_table; >> rwlock_t hash_lock; > > Given that these lists are chains in a hash table, it would make more > sense to use hlist_head rather than list_head. They are designed for > exactly that purpose - and are smaller. > > Actually, I'd really like to see hlist_bl_head used - so there was one > bit-spin-lock per chain, and use RCU for protecting searches. > However that would have to be left for later - no point delaying this > patch set for some minor performance gains. > > But as you need to change this, I think it would be best to change to > hlist_head. Got it. I will update and test it. thanks, Kinglong Mee > > By the way, I see lots of nice clean-ups in this series. Thanks! > > NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h index 04ee5a2..ecc0ff6 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 list_head 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 list_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..ad2155c 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_LIST_HEAD(&h->cache_list); h->flags = 0; kref_init(&h->ref); h->expiry_time = now + CACHE_NEW_EXPIRY; @@ -54,15 +54,16 @@ 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 *tmp; + struct list_head *head, *pos, *tpos; head = &detail->hash_table[hash]; read_lock(&detail->hash_lock); - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { - struct cache_head *tmp = *hp; + list_for_each_safe(pos, tpos, head) { + tmp = list_entry(pos, struct cache_head, cache_list); if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) /* This entry is expired, we will discard it. */ @@ -88,12 +89,11 @@ 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; + list_for_each_safe(pos, tpos, head) { + tmp = list_entry(pos, struct cache_head, cache_list); if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) { - *hp = tmp->next; - tmp->next = NULL; + list_del_init(&tmp->cache_list); detail->entries --; freeme = tmp; break; @@ -104,8 +104,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, return tmp; } } - new->next = *head; - *head = new; + + list_add(&new->cache_list, head); detail->entries++; cache_get(new); write_unlock(&detail->hash_lock); @@ -143,7 +143,6 @@ 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 +167,13 @@ 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; + list_add(&tmp->cache_list, &detail->hash_table[hash]); detail->entries++; cache_get(tmp); cache_fresh_locked(tmp, new->expiry_time); @@ -416,42 +413,44 @@ 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) + list_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, *putme = NULL; + struct list_head *head, *pos, *tpos; struct cache_detail *d; 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]; + list_for_each_safe(pos, tpos, head) { + ch = list_entry(pos, struct cache_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; + list_del_init(pos); current_detail->entries--; + putme = ch; rv = 1; break; } write_unlock(¤t_detail->hash_lock); d = current_detail; - if (!ch) + if (!putme) current_index ++; spin_unlock(&cache_list_lock); - if (ch) { - set_bit(CACHE_CLEANED, &ch->flags); - cache_fresh_unlocked(ch, d); - cache_put(ch, d); + if (putme) { + set_bit(CACHE_CLEANED, &putme->flags); + cache_fresh_unlocked(putme, d); + cache_put(putme, d); } } else spin_unlock(&cache_list_lock); @@ -1277,6 +1276,7 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) unsigned int hash, entry; struct cache_head *ch; struct cache_detail *cd = m->private; + struct list_head *ptr, *tptr; read_lock(&cd->hash_lock); if (!n--) @@ -1284,19 +1284,22 @@ 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) + list_for_each_safe(ptr, tptr, &cd->hash_table[hash]) { + ch = list_entry(ptr, struct cache_head, cache_list); if (!entry--) return ch; + } n &= ~((1LL<<32) - 1); do { hash++; n += 1LL<<32; } while(hash < cd->hash_size && - cd->hash_table[hash]==NULL); + list_empty(&cd->hash_table[hash])); if (hash >= cd->hash_size) return NULL; *pos = n+1; - return cd->hash_table[hash]; + return list_first_entry_or_null(&cd->hash_table[hash], + struct cache_head, cache_list); } EXPORT_SYMBOL_GPL(cache_seq_start); @@ -1308,23 +1311,24 @@ 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 (list_is_last(&ch->cache_list, &cd->hash_table[hash])) { hash++; *pos += 1LL<<32; } else { ++*pos; - return ch->next; + return list_next_entry(ch, cache_list); } *pos &= ~((1LL<<32) - 1); while (hash < cd->hash_size && - cd->hash_table[hash] == NULL) { + list_empty(&cd->hash_table[hash])) { hash++; *pos += 1LL<<32; } if (hash >= cd->hash_size) return NULL; ++*pos; - return cd->hash_table[hash]; + return list_first_entry_or_null(&cd->hash_table[hash], + struct cache_head, cache_list); } EXPORT_SYMBOL_GPL(cache_seq_next); @@ -1666,17 +1670,21 @@ 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 list_head), GFP_KERNEL); if (cd->hash_table == NULL) { kfree(cd); return ERR_PTR(-ENOMEM); } + + for (i = 0; i < cd->hash_size; i++) + INIT_LIST_HEAD(&cd->hash_table[i]); cd->net = net; return cd; }
Switch using list_head for cache_head in cache_detail, it is useful of remove an cache_head entry directly from cache_detail. v7, same as v6. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> --- include/linux/sunrpc/cache.h | 4 +-- net/sunrpc/cache.c | 74 ++++++++++++++++++++++++-------------------- 2 files changed, 43 insertions(+), 35 deletions(-)