Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

[pandora-kernel.git] / fs / eventpoll.c

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index ba2f9ec..c5c424f 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -234,8 +234,6 @@ struct ep_pqueue {
 /*
  * Configuration options available inside /proc/sys/fs/epoll/
  */
-/* Maximum number of epoll devices, per user */
-static int max_user_instances __read_mostly;
 /* Maximum number of epoll watched descriptors, per user */
 static int max_user_watches __read_mostly;
 
@@ -260,14 +258,6 @@ static struct kmem_cache *pwq_cache __read_mostly;
 static int zero;
 
 ctl_table epoll_table[] = {
-       {
-               .procname       = "max_user_instances",
-               .data           = &max_user_instances,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = &proc_dointvec_minmax,
-               .extra1         = &zero,
-       },
        {
                .procname       = "max_user_watches",
                .data           = &max_user_watches,
@@ -427,10 +417,10 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi)
        ep_unregister_pollwait(ep, epi);
 
        /* Remove the current item from the list of epoll hooks */
-       spin_lock(&file->f_ep_lock);
+       spin_lock(&file->f_lock);
        if (ep_is_linked(&epi->fllink))
                list_del_init(&epi->fllink);
-       spin_unlock(&file->f_ep_lock);
+       spin_unlock(&file->f_lock);
 
        rb_erase(&epi->rbn, &ep->rbr);
 
@@ -491,7 +481,6 @@ static void ep_free(struct eventpoll *ep)
 
        mutex_unlock(&epmutex);
        mutex_destroy(&ep->mtx);
-       atomic_dec(&ep->user->epoll_devs);
        free_uid(ep->user);
        kfree(ep);
 }
@@ -549,7 +538,7 @@ void eventpoll_release_file(struct file *file)
        struct epitem *epi;
 
        /*
-        * We don't want to get "file->f_ep_lock" because it is not
+        * We don't want to get "file->f_lock" because it is not
         * necessary. It is not necessary because we're in the "struct file"
         * cleanup path, and this means that noone is using this file anymore.
         * So, for example, epoll_ctl() cannot hit here sicne if we reach this
@@ -558,6 +547,8 @@ void eventpoll_release_file(struct file *file)
         * will correctly serialize the operation. We do need to acquire
         * "ep->mtx" after "epmutex" because ep_remove() requires it when called
         * from anywhere but ep_free().
+        *
+        * Besides, ep_remove() acquires the lock, so we can't hold it here.
         */
        mutex_lock(&epmutex);
 
@@ -581,10 +572,6 @@ static int ep_alloc(struct eventpoll **pep)
        struct eventpoll *ep;
 
        user = get_current_user();
-       error = -EMFILE;
-       if (unlikely(atomic_read(&user->epoll_devs) >=
-                       max_user_instances))
-               goto free_uid;
        error = -ENOMEM;
        ep = kzalloc(sizeof(*ep), GFP_KERNEL);
        if (unlikely(!ep))
@@ -800,9 +787,9 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
                goto error_unregister;
 
        /* Add the current item to the list of active epoll hook for this file */
-       spin_lock(&tfile->f_ep_lock);
+       spin_lock(&tfile->f_lock);
        list_add_tail(&epi->fllink, &tfile->f_ep_links);
-       spin_unlock(&tfile->f_ep_lock);
+       spin_unlock(&tfile->f_lock);
 
        /*
         * Add the current item to the RB tree. All RB tree operations are
@@ -1141,7 +1128,6 @@ SYSCALL_DEFINE1(epoll_create1, int, flags)
                              flags & O_CLOEXEC);
        if (fd < 0)
                ep_free(ep);
-       atomic_inc(&ep->user->epoll_devs);
 
 error_return:
        DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n",
@@ -1366,8 +1352,10 @@ static int __init eventpoll_init(void)
        struct sysinfo si;
 
        si_meminfo(&si);
-       max_user_instances = 128;
-       max_user_watches = (((si.totalram - si.totalhigh) / 32) << PAGE_SHIFT) /
+       /*
+        * Allows top 4% of lomem to be allocated for epoll watches (per user).
+        */
+       max_user_watches = (((si.totalram - si.totalhigh) / 25) << PAGE_SHIFT) /
                EP_ITEM_COST;
 
        /* Initialize the structure used to perform safe poll wait head wake ups */