diff -Nru linux-2.5.46.vanilla/fs/eventpoll.c linux-2.5.46.epoll/fs/eventpoll.c --- linux-2.5.46.vanilla/fs/eventpoll.c Mon Nov 4 15:45:35 2002 +++ linux-2.5.46.epoll/fs/eventpoll.c Wed Nov 6 10:36:06 2002 @@ -61,8 +61,12 @@ /* Maximum storage for the eventpoll interest set */ #define EP_MAX_FDS_SIZE (1024 * 128) -/* We don't want the hash to be smaller than this */ -#define EP_MIN_HASH_SIZE 101 +/* + * We don't want the hash to be smaller than this. This is basically + * the highest prime lower than (PAGE_SIZE / sizeof(struct list_head)). + */ +#define EP_MIN_HASH_SIZE 509 + /* * Event buffer dimension used to cache events before sending them in * userspace with a __copy_to_user(). The event buffer is in stack, @@ -188,6 +192,7 @@ static int ep_is_prime(int n); +static int ep_size_hash(int hintsize); static int ep_getfd(int *efd, struct inode **einode, struct file **efile); static int ep_alloc_pages(char **pages, int numpages); static int ep_free_pages(char **pages, int numpages); @@ -201,7 +206,6 @@ static void ep_release_epitem(struct epitem *dpi); static void ep_ptable_queue_proc(void *priv, wait_queue_head_t *whead); static int ep_insert(struct eventpoll *ep, struct pollfd *pfd, struct file *tfile); -static unsigned int ep_get_file_events(struct file *file); static int ep_modify(struct eventpoll *ep, struct epitem *dpi, unsigned int events); static int ep_unlink(struct eventpoll *ep, struct epitem *dpi); static int ep_remove(struct eventpoll *ep, struct epitem *dpi); @@ -252,14 +256,14 @@ -/* Report if the number is prime. Needed to correctly size the hash */ +/* Report if the number is prime. Needed to correctly size the hash */ static int ep_is_prime(int n) { if (n > 3) { if (n & 1) { int i, hn = n / 2; - + for (i = 3; i < hn; i += 2) if (!(n % i)) return 0; @@ -296,9 +300,30 @@ } +static int ep_size_hash(int hintsize) +{ + int maxsize = (EP_MAX_HPAGES - 1) * EP_HENTRY_X_PAGE; + + /* + * Search the nearest prime number higher than "hintsize" and + * smaller than "maxsize". + */ + for (; !ep_is_prime(hintsize); hintsize++); + if (hintsize < EP_MIN_HASH_SIZE) + hintsize = EP_MIN_HASH_SIZE; + else if (hintsize >= maxsize) + for (hintsize = maxsize - 1; !ep_is_prime(hintsize); hintsize--); + + return hintsize; +} + + /* * It opens an eventpoll file descriptor by suggesting a storage of "size" - * file descriptors. It is the kernel part of the userspace epoll_create(2). + * file descriptors. The size parameter is just an hint about how to size + * data structures. It won't prevent the user to store more than "size" + * file descriptors inside the epoll interface. It is the kernel part of + * the userspace epoll_create(2). */ asmlinkage int sys_epoll_create(int size) { @@ -309,10 +334,8 @@ DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d)\n", current, size)); - /* Search the nearest prime number higher than "size" */ - for (; !ep_is_prime(size); size++); - if (size < EP_MIN_HASH_SIZE) - size = EP_MIN_HASH_SIZE; + /* Correctly size the hash */ + size = ep_size_hash(size); /* * Creates all the items needed to setup an eventpoll file. That is, @@ -567,7 +590,7 @@ eexit_2: put_filp(file); eexit_1: - return error; + return error; } @@ -723,8 +746,7 @@ write_unlock_irqrestore(&eplock, flags); /* Free hash pages */ - if (ep->nhpages > 0) - ep_free_pages(ep->hpages, ep->nhpages); + ep_free_pages(ep->hpages, ep->nhpages); } @@ -827,22 +849,26 @@ dpi->wait[i].base = dpi; } - /* Attach the item to the poll hooks */ + /* Initialize the poll table using the queue callback */ poll_initwait_ex(&pt, 1, ep_ptable_queue_proc, dpi); - revents = tfile->f_op->poll(tfile, &pt); - poll_freewait(&pt); /* We have to drop the new item inside our item list to keep track of it */ write_lock_irqsave(&ep->lock, flags); + /* Add the current item to the hash table */ list_add(&dpi->llink, ep_hash_entry(ep, ep_hash_index(ep, tfile))); + /* Attach the item to the poll hooks and get current event bits */ + revents = tfile->f_op->poll(tfile, &pt); + /* If the file is already "ready" we drop it inside the ready list */ if ((revents & pfd->events) && !EP_IS_LINKED(&dpi->rdllink)) list_add(&dpi->rdllink, &ep->rdllist); write_unlock_irqrestore(&ep->lock, flags); + poll_freewait(&pt); + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_insert(%p, %d)\n", current, ep, pfd->fd)); @@ -854,12 +880,13 @@ /* - * Returns the current events of the given file. It uses the special - * poll table initialization to avoid any poll queue insertion. + * Modify the interest event mask by dropping an event if the new mask + * has a match in the current file status. */ -static unsigned int ep_get_file_events(struct file *file) +static int ep_modify(struct eventpoll *ep, struct epitem *dpi, unsigned int events) { unsigned int revents; + unsigned long flags; poll_table pt; /* @@ -870,26 +897,12 @@ */ poll_initwait_ex(&pt, 0, NULL, NULL); - revents = file->f_op->poll(file, &pt); - - poll_freewait(&pt); - return revents; -} - - -/* - * Modify the interest event mask by dropping an event if the new mask - * has a match in the current file status. - */ -static int ep_modify(struct eventpoll *ep, struct epitem *dpi, unsigned int events) -{ - unsigned int revents; - unsigned long flags; - - revents = ep_get_file_events(dpi->file); - write_lock_irqsave(&ep->lock, flags); + /* Get current event bits */ + revents = dpi->file->f_op->poll(dpi->file, &pt); + + /* Set the new event interest mask */ dpi->pfd.events = events; /* If the file is already "ready" we drop it inside the ready list */ @@ -898,6 +911,8 @@ write_unlock_irqrestore(&ep->lock, flags); + poll_freewait(&pt); + return 0; } @@ -1074,6 +1089,14 @@ /* Remove the item from the ready list */ EP_LIST_DEL(&dpi->rdllink); + /* + * If the item is not linked to the main has table this means that + * it's on the way to be removed and we don't want to send events + * to such file descriptor. + */ + if (!EP_IS_LINKED(&dpi->llink)) + continue; + /* Fetch event bits from the signaled file */ revents = dpi->file->f_op->poll(dpi->file, &pt); @@ -1126,12 +1149,10 @@ wait_queue_t wait; /* - * Calculate the timeout by checking for the "infinite" value ( -1 ) - * and the overflow condition ( > MAX_SCHEDULE_TIMEOUT / HZ ). The - * passed timeout is in milliseconds, that why (t * HZ) / 1000. + * Calculate the timeout by checking for the "infinite" value ( -1 ). + * The passed timeout is in milliseconds, that why (t * HZ) / 1000. */ - jtimeout = timeout == -1 || timeout > MAX_SCHEDULE_TIMEOUT / HZ ? - MAX_SCHEDULE_TIMEOUT: (timeout * HZ) / 1000; + jtimeout = timeout == -1 ? MAX_SCHEDULE_TIMEOUT: (timeout * HZ) / 1000; retry: write_lock_irqsave(&ep->lock, flags); diff -Nru linux-2.5.46.vanilla/include/linux/eventpoll.h linux-2.5.46.epoll/include/linux/eventpoll.h --- linux-2.5.46.vanilla/include/linux/eventpoll.h Mon Nov 4 15:45:36 2002 +++ linux-2.5.46.epoll/include/linux/eventpoll.h Tue Nov 5 11:13:26 2002 @@ -14,10 +14,6 @@ #ifndef _LINUX_EVENTPOLL_H #define _LINUX_EVENTPOLL_H -/* Forward declarations to avoid compiler errors */ -struct file; -struct pollfd; - /* Valid opcodes to issue to sys_epoll_ctl() */ #define EP_CTL_ADD 1 @@ -25,6 +21,13 @@ #define EP_CTL_MOD 3 +#ifdef __KERNEL__ + +/* Forward declarations to avoid compiler errors */ +struct file; +struct pollfd; + + /* Kernel space functions implementing the user space "epoll" API */ asmlinkage int sys_epoll_create(int size); asmlinkage int sys_epoll_ctl(int epfd, int op, int fd, unsigned int events); @@ -34,6 +37,7 @@ /* Used in fs/file_table.c:__fput() to unlink files from the eventpoll interface */ void ep_notify_file_close(struct file *file); +#endif /* #ifdef __KERNEL__ */ -#endif +#endif /* #ifndef _LINUX_EVENTPOLL_H */ diff -Nru linux-2.5.46.vanilla/include/linux/poll.h linux-2.5.46.epoll/include/linux/poll.h --- linux-2.5.46.vanilla/include/linux/poll.h Mon Nov 4 15:45:37 2002 +++ linux-2.5.46.epoll/include/linux/poll.h Wed Nov 6 10:44:10 2002 @@ -28,15 +28,6 @@ __pollwait(filp, wait_address, p); } -static inline void poll_initwait(poll_table* pt) -{ - pt->queue = 1; - pt->qproc = NULL; - pt->priv = NULL; - pt->error = 0; - pt->table = NULL; -} - static inline void poll_initwait_ex(poll_table* pt, int queue, void (*qproc)(void *, wait_queue_head_t *), void *priv) @@ -46,6 +37,12 @@ pt->priv = priv; pt->error = 0; pt->table = NULL; +} + +static inline void poll_initwait(poll_table* pt) +{ + + poll_initwait_ex(pt, 1, NULL, NULL); } extern void poll_freewait(poll_table* pt);