The patch titled
cgroups: clean up cgroup_pidlist_find() a bit
has been added to the -mm tree. Its filename is
cgroups-clean-up-cgroup_pidlist_find-a-bit.patch
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------------------------------------------------------
Subject: cgroups: clean up cgroup_pidlist_find() a bit
From: Li Zefan <lizf@xxxxxxxxxxxxxx>
Don't call get_pid_ns() before we locate/alloc the ns.
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Serge Hallyn <serue@xxxxxxxxxx>
Acked-by: Paul Menage <menage@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/cgroup.c | 8 -
kernel/cgroup.c.orig | 208 -----------------------------------------
2 files changed, 4 insertions(+), 212 deletions(-)
diff -puN kernel/cgroup.c~cgroups-clean-up-cgroup_pidlist_find-a-bit kernel/cgroup.c
--- a/kernel/cgroup.c~cgroups-clean-up-cgroup_pidlist_find-a-bit
+++ a/kernel/cgroup.c
@@ -2582,7 +2582,8 @@ static struct cgroup_pidlist *cgroup_pid
{
struct cgroup_pidlist *l;
/* don't need task_nsproxy() if we're looking at ourself */
- struct pid_namespace *ns = get_pid_ns(current->nsproxy->pid_ns);
+ struct pid_namespace *ns = current->nsproxy->pid_ns;
+
/*
* We can't drop the pidlist_mutex before taking the l->mutex in case
* the last ref-holder is trying to remove l from the list at the same
@@ -2592,8 +2593,6 @@ static struct cgroup_pidlist *cgroup_pid
mutex_lock(&cgrp->pidlist_mutex);
list_for_each_entry(l, &cgrp->pidlists, links) {
if (l->key.type == type && l->key.ns == ns) {
- /* found a matching list - drop the extra refcount */
- put_pid_ns(ns);
/* make sure l doesn't vanish out from under us */
down_write(&l->mutex);
mutex_unlock(&cgrp->pidlist_mutex);
@@ -2604,13 +2603,12 @@ static struct cgroup_pidlist *cgroup_pid
l = kmalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL);
if (!l) {
mutex_unlock(&cgrp->pidlist_mutex);
- put_pid_ns(ns);
return l;
}
init_rwsem(&l->mutex);
down_write(&l->mutex);
l->key.type = type;
- l->key.ns = ns;
+ l->key.ns = get_pid_ns(ns);
l->use_count = 0; /* don't increment here */
l->list = NULL;
l->owner = cgrp;
diff -puN kernel/cgroup.c.orig~cgroups-clean-up-cgroup_pidlist_find-a-bit kernel/cgroup.c.orig
--- a/kernel/cgroup.c.orig~cgroups-clean-up-cgroup_pidlist_find-a-bit
+++ a/kernel/cgroup.c.orig
@@ -4,10 +4,6 @@
* Based originally on the cpuset system, extracted by Paul Menage
* Copyright (C) 2006 Google, Inc
*
- * Notifications support
- * Copyright (C) 2009 Nokia Corporation
- * Author: Kirill A. Shutemov
- *
* Copyright notices from the original cpuset code:
* --------------------------------------------------
* Copyright (C) 2003 BULL SA.
@@ -56,8 +52,6 @@
#include <linux/pid_namespace.h>
#include <linux/idr.h>
#include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */
-#include <linux/eventfd.h>
-#include <linux/poll.h>
#include <asm/atomic.h>
@@ -157,35 +151,6 @@ struct css_id {
unsigned short stack[0]; /* Array of Length (depth+1) */
};
-/*
- * cgroup_event represents events which userspace want to recieve.
- */
-struct cgroup_event {
- /*
- * Cgroup which the event belongs to.
- */
- struct cgroup *cgrp;
- /*
- * Control file which the event associated.
- */
- struct cftype *cft;
- /*
- * eventfd to signal userspace about the event.
- */
- struct eventfd_ctx *eventfd;
- /*
- * Each of these stored in a list by the cgroup.
- */
- struct list_head list;
- /*
- * All fields below needed to unregister event when
- * userspace closes eventfd.
- */
- poll_table pt;
- wait_queue_head_t *wqh;
- wait_queue_t wait;
- struct work_struct remove;
-};
/* The list of hierarchy roots */
@@ -780,28 +745,14 @@ static struct inode *cgroup_new_inode(mo
static int cgroup_call_pre_destroy(struct cgroup *cgrp)
{
struct cgroup_subsys *ss;
- struct cgroup_event *event, *tmp;
int ret = 0;
for_each_subsys(cgrp->root, ss)
if (ss->pre_destroy) {
ret = ss->pre_destroy(ss, cgrp);
if (ret)
- goto out;
+ break;
}
-
- /*
- * Unregister events and notify userspace.
- */
- spin_lock(&cgrp->event_list_lock);
- list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) {
- list_del(&event->list);
- eventfd_signal(event->eventfd, 1);
- schedule_work(&event->remove);
- }
- spin_unlock(&cgrp->event_list_lock);
-
-out:
return ret;
}
@@ -1273,8 +1224,6 @@ static void init_cgroup_housekeeping(str
INIT_LIST_HEAD(&cgrp->release_list);
INIT_LIST_HEAD(&cgrp->pidlists);
mutex_init(&cgrp->pidlist_mutex);
- INIT_LIST_HEAD(&cgrp->event_list);
- spin_lock_init(&cgrp->event_list_lock);
}
static void init_cgroup_root(struct cgroupfs_root *root)
@@ -2113,16 +2062,6 @@ static const struct inode_operations cgr
.rename = cgroup_rename,
};
-/*
- * Check if a file is a control file
- */
-static inline struct cftype *__file_cft(struct file *file)
-{
- if (file->f_dentry->d_inode->i_fop != &cgroup_file_operations)
- return ERR_PTR(-EINVAL);
- return __d_cft(file->f_dentry);
-}
-
static int cgroup_create_file(struct dentry *dentry, mode_t mode,
struct super_block *sb)
{
@@ -2978,146 +2917,6 @@ static int cgroup_write_notify_on_releas
return 0;
}
-static void cgroup_event_remove(struct work_struct *work)
-{
- struct cgroup_event *event = container_of(work, struct cgroup_event,
- remove);
- struct cgroup *cgrp = event->cgrp;
-
- /* TODO: check return code*/
- event->cft->unregister_event(cgrp, event->cft, event->eventfd);
-
- eventfd_ctx_put(event->eventfd);
- remove_wait_queue(event->wqh, &event->wait);
- kfree(event);
-}
-
-static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
- int sync, void *key)
-{
- struct cgroup_event *event = container_of(wait,
- struct cgroup_event, wait);
- struct cgroup *cgrp = event->cgrp;
- unsigned long flags = (unsigned long)key;
-
- if (flags & POLLHUP) {
- spin_lock(&cgrp->event_list_lock);
- list_del(&event->list);
- spin_unlock(&cgrp->event_list_lock);
- schedule_work(&event->remove);
- }
-
- return 0;
-}
-
-static void cgroup_event_ptable_queue_proc(struct file *file,
- wait_queue_head_t *wqh, poll_table *pt)
-{
- struct cgroup_event *event = container_of(pt,
- struct cgroup_event, pt);
-
- event->wqh = wqh;
- add_wait_queue(wqh, &event->wait);
-}
-
-static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
-{
- struct cgroup_event *event = NULL;
- unsigned int efd, cfd;
- struct file *efile = NULL;
- struct file *cfile = NULL;
- char *endp;
- int ret;
-
- efd = simple_strtoul(buffer, &endp, 10);
- if (*endp != ' ')
- return -EINVAL;
- buffer = endp + 1;
-
- cfd = simple_strtoul(buffer, &endp, 10);
- if ((*endp != ' ') && (*endp != '\0'))
- return -EINVAL;
- buffer = endp + 1;
-
- event = kzalloc(sizeof(*event), GFP_KERNEL);
- if (!event)
- return -ENOMEM;
- event->cgrp = cgrp;
- INIT_LIST_HEAD(&event->list);
- init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc);
- init_waitqueue_func_entry(&event->wait, cgroup_event_wake);
- INIT_WORK(&event->remove, cgroup_event_remove);
-
- efile = eventfd_fget(efd);
- if (IS_ERR(efile)) {
- ret = PTR_ERR(efile);
- goto fail;
- }
-
- event->eventfd = eventfd_ctx_fileget(efile);
- if (IS_ERR(event->eventfd)) {
- ret = PTR_ERR(event->eventfd);
- goto fail;
- }
-
- cfile = fget(cfd);
- if (!cfile) {
- ret = -EBADF;
- goto fail;
- }
-
- /* the process need read permission on control file */
- ret = file_permission(cfile, MAY_READ);
- if (ret < 0)
- goto fail;
-
- event->cft = __file_cft(cfile);
- if (IS_ERR(event->cft)) {
- ret = PTR_ERR(event->cft);
- goto fail;
- }
-
- if (!event->cft->register_event || !event->cft->unregister_event) {
- ret = -EINVAL;
- goto fail;
- }
-
- ret = event->cft->register_event(cgrp, event->cft,
- event->eventfd, buffer);
- if (ret)
- goto fail;
-
- if (efile->f_op->poll(efile, &event->pt) & POLLHUP) {
- event->cft->unregister_event(cgrp, event->cft, event->eventfd);
- ret = 0;
- goto fail;
- }
-
- spin_lock(&cgrp->event_list_lock);
- list_add(&event->list, &cgrp->event_list);
- spin_unlock(&cgrp->event_list_lock);
-
- fput(cfile);
- fput(efile);
-
- return 0;
-
-fail:
- if (!IS_ERR(cfile))
- fput(cfile);
-
- if (event && event->eventfd && !IS_ERR(event->eventfd))
- eventfd_ctx_put(event->eventfd);
-
- if (!IS_ERR(efile))
- fput(efile);
-
- kfree(event);
-
- return ret;
-}
-
/*
* for the common functions, 'private' gives the type of file
*/
@@ -3143,11 +2942,6 @@ static struct cftype files[] = {
.read_u64 = cgroup_read_notify_on_release,
.write_u64 = cgroup_write_notify_on_release,
},
- {
- .name = CGROUP_FILE_GENERIC_PREFIX "event_control",
- .write_string = cgroup_write_event_control,
- .mode = S_IWUGO,
- },
};
static struct cftype cft_release_agent = {
_
Patches currently in -mm which might be from lizf@xxxxxxxxxxxxxx are
linux-next.patch
cgroups-fix-to-return-errno-in-a-failure-path.patch
lib-stringc-simplify-strnstr.patch
cgroup-introduce-cancel_attach.patch
cgroup-introduce-coalesce-css_get-and-css_put.patch
cgroups-revamp-subsys-array.patch
cgroups-subsystem-module-loading-interface.patch
cgroups-subsystem-module-loading-interface-fix.patch
cgroups-subsystem-module-unloading.patch
cgroups-net_cls-as-module.patch
cgroups-blkio-subsystem-as-module.patch
cgroups-clean-up-cgroup_pidlist_find-a-bit.patch
memcg-add-interface-to-move-charge-at-task-migration.patch
memcg-move-charges-of-anonymous-page.patch
memcg-move-charges-of-anonymous-page-cleanup.patch
memcg-improve-performance-in-moving-charge.patch
memcg-avoid-oom-during-moving-charge.patch
memcg-move-charges-of-anonymous-swap.patch
memcg-move-charges-of-anonymous-swap-fix.patch
memcg-improve-performance-in-moving-swap-charge.patch
memcg-improve-performance-in-moving-swap-charge-fix.patch
cgroup-implement-eventfd-based-generic-api-for-notifications.patch
cgroup-implement-eventfd-based-generic-api-for-notifications-kconfig-fix.patch
cgroup-implement-eventfd-based-generic-api-for-notifications-fixes.patch
memcg-extract-mem_group_usage-from-mem_cgroup_read.patch
memcg-rework-usage-of-stats-by-soft-limit.patch
memcg-implement-memory-thresholds.patch
memcg-implement-memory-thresholds-checkpatch-fixes.patch
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