Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946803AbWKALgl (ORCPT ); Wed, 1 Nov 2006 06:36:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423973AbWKALgl (ORCPT ); Wed, 1 Nov 2006 06:36:41 -0500 Received: from dea.vocord.ru ([217.67.177.50]:49837 "EHLO kano.factory.vocord.ru") by vger.kernel.org with ESMTP id S1423648AbWKALgj convert rfc822-to-8bit (ORCPT ); Wed, 1 Nov 2006 06:36:39 -0500 Cc: David Miller , Ulrich Drepper , Andrew Morton , Evgeniy Polyakov , netdev , Zach Brown , Christoph Hellwig , Chase Venters , Johann Borck , linux-kernel@vger.kernel.org Subject: [take22 2/4] kevent: poll/select() notifications. In-Reply-To: <11623809632360@2ka.mipt.ru> X-Mailer: gregkh_patchbomb Date: Wed, 1 Nov 2006 14:36:03 +0300 Message-Id: <11623809631966@2ka.mipt.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Reply-To: Evgeniy Polyakov To: Evgeniy Polyakov Content-Transfer-Encoding: 7BIT From: Evgeniy Polyakov Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7483 Lines: 277 poll/select() notifications. This patch includes generic poll/select notifications. kevent_poll works simialr to epoll and has the same issues (callback is invoked not from internal state machine of the caller, but through process awake, a lot of allocations and so on). Signed-off-by: Evgeniy Polyakov diff --git a/include/linux/fs.h b/include/linux/fs.h index 5baf3a1..f81299f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -276,6 +276,7 @@ #include #include #include #include +#include #include #include @@ -586,6 +587,10 @@ #ifdef CONFIG_INOTIFY struct mutex inotify_mutex; /* protects the watches list */ #endif +#ifdef CONFIG_KEVENT_SOCKET + struct kevent_storage st; +#endif + unsigned long i_state; unsigned long dirtied_when; /* jiffies of first dirtying */ @@ -739,6 +744,9 @@ #ifdef CONFIG_EPOLL struct list_head f_ep_links; spinlock_t f_ep_lock; #endif /* #ifdef CONFIG_EPOLL */ +#ifdef CONFIG_KEVENT_POLL + struct kevent_storage st; +#endif struct address_space *f_mapping; }; extern spinlock_t files_lock; diff --git a/kernel/kevent/kevent_poll.c b/kernel/kevent/kevent_poll.c new file mode 100644 index 0000000..94facbb --- /dev/null +++ b/kernel/kevent/kevent_poll.c @@ -0,0 +1,222 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static kmem_cache_t *kevent_poll_container_cache; +static kmem_cache_t *kevent_poll_priv_cache; + +struct kevent_poll_ctl +{ + struct poll_table_struct pt; + struct kevent *k; +}; + +struct kevent_poll_wait_container +{ + struct list_head container_entry; + wait_queue_head_t *whead; + wait_queue_t wait; + struct kevent *k; +}; + +struct kevent_poll_private +{ + struct list_head container_list; + spinlock_t container_lock; +}; + +static int kevent_poll_enqueue(struct kevent *k); +static int kevent_poll_dequeue(struct kevent *k); +static int kevent_poll_callback(struct kevent *k); + +static int kevent_poll_wait_callback(wait_queue_t *wait, + unsigned mode, int sync, void *key) +{ + struct kevent_poll_wait_container *cont = + container_of(wait, struct kevent_poll_wait_container, wait); + struct kevent *k = cont->k; + struct file *file = k->st->origin; + u32 revents; + + revents = file->f_op->poll(file, NULL); + + kevent_storage_ready(k->st, NULL, revents); + + return 0; +} + +static void kevent_poll_qproc(struct file *file, wait_queue_head_t *whead, + struct poll_table_struct *poll_table) +{ + struct kevent *k = + container_of(poll_table, struct kevent_poll_ctl, pt)->k; + struct kevent_poll_private *priv = k->priv; + struct kevent_poll_wait_container *cont; + unsigned long flags; + + cont = kmem_cache_alloc(kevent_poll_container_cache, SLAB_KERNEL); + if (!cont) { + kevent_break(k); + return; + } + + cont->k = k; + init_waitqueue_func_entry(&cont->wait, kevent_poll_wait_callback); + cont->whead = whead; + + spin_lock_irqsave(&priv->container_lock, flags); + list_add_tail(&cont->container_entry, &priv->container_list); + spin_unlock_irqrestore(&priv->container_lock, flags); + + add_wait_queue(whead, &cont->wait); +} + +static int kevent_poll_enqueue(struct kevent *k) +{ + struct file *file; + int err, ready = 0; + unsigned int revents; + struct kevent_poll_ctl ctl; + struct kevent_poll_private *priv; + + file = fget(k->event.id.raw[0]); + if (!file) + return -EBADF; + + err = -EINVAL; + if (!file->f_op || !file->f_op->poll) + goto err_out_fput; + + err = -ENOMEM; + priv = kmem_cache_alloc(kevent_poll_priv_cache, SLAB_KERNEL); + if (!priv) + goto err_out_fput; + + spin_lock_init(&priv->container_lock); + INIT_LIST_HEAD(&priv->container_list); + + k->priv = priv; + + ctl.k = k; + init_poll_funcptr(&ctl.pt, &kevent_poll_qproc); + + err = kevent_storage_enqueue(&file->st, k); + if (err) + goto err_out_free; + + revents = file->f_op->poll(file, &ctl.pt); + if (revents & k->event.event) { + ready = 1; + kevent_poll_dequeue(k); + } + + return ready; + +err_out_free: + kmem_cache_free(kevent_poll_priv_cache, priv); +err_out_fput: + fput(file); + return err; +} + +static int kevent_poll_dequeue(struct kevent *k) +{ + struct file *file = k->st->origin; + struct kevent_poll_private *priv = k->priv; + struct kevent_poll_wait_container *w, *n; + unsigned long flags; + + kevent_storage_dequeue(k->st, k); + + spin_lock_irqsave(&priv->container_lock, flags); + list_for_each_entry_safe(w, n, &priv->container_list, container_entry) { + list_del(&w->container_entry); + remove_wait_queue(w->whead, &w->wait); + kmem_cache_free(kevent_poll_container_cache, w); + } + spin_unlock_irqrestore(&priv->container_lock, flags); + + kmem_cache_free(kevent_poll_priv_cache, priv); + k->priv = NULL; + + fput(file); + + return 0; +} + +static int kevent_poll_callback(struct kevent *k) +{ + struct file *file = k->st->origin; + unsigned int revents = file->f_op->poll(file, NULL); + + k->event.ret_data[0] = revents & k->event.event; + + return (revents & k->event.event); +} + +static int __init kevent_poll_sys_init(void) +{ + struct kevent_callbacks pc = { + .callback = &kevent_poll_callback, + .enqueue = &kevent_poll_enqueue, + .dequeue = &kevent_poll_dequeue}; + + kevent_poll_container_cache = kmem_cache_create("kevent_poll_container_cache", + sizeof(struct kevent_poll_wait_container), 0, 0, NULL, NULL); + if (!kevent_poll_container_cache) { + printk(KERN_ERR "Failed to create kevent poll container cache.\n"); + return -ENOMEM; + } + + kevent_poll_priv_cache = kmem_cache_create("kevent_poll_priv_cache", + sizeof(struct kevent_poll_private), 0, 0, NULL, NULL); + if (!kevent_poll_priv_cache) { + printk(KERN_ERR "Failed to create kevent poll private data cache.\n"); + kmem_cache_destroy(kevent_poll_container_cache); + kevent_poll_container_cache = NULL; + return -ENOMEM; + } + + kevent_add_callbacks(&pc, KEVENT_POLL); + + printk(KERN_INFO "Kevent poll()/select() subsystem has been initialized.\n"); + return 0; +} + +static struct lock_class_key kevent_poll_key; + +void kevent_poll_reinit(struct file *file) +{ + lockdep_set_class(&file->st.lock, &kevent_poll_key); +} + +static void __exit kevent_poll_sys_fini(void) +{ + kmem_cache_destroy(kevent_poll_priv_cache); + kmem_cache_destroy(kevent_poll_container_cache); +} + +module_init(kevent_poll_sys_init); +module_exit(kevent_poll_sys_fini); 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