linux_dsm_epyc7002/arch/powerpc/platforms/pseries/cmm.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

752 lines
18 KiB
C

/*
* Collaborative memory management interface.
*
* Copyright (C) 2008 IBM Corporation
* Author(s): Brian King (brking@linux.vnet.ibm.com),
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/oom.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/stringify.h>
#include <linux/swap.h>
#include <linux/sysdev.h>
#include <asm/firmware.h>
#include <asm/hvcall.h>
#include <asm/mmu.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
#include <linux/memory.h>
#include "plpar_wrappers.h"
#define CMM_DRIVER_VERSION "1.0.0"
#define CMM_DEFAULT_DELAY 1
#define CMM_HOTPLUG_DELAY 5
#define CMM_DEBUG 0
#define CMM_DISABLE 0
#define CMM_OOM_KB 1024
#define CMM_MIN_MEM_MB 256
#define KB2PAGES(_p) ((_p)>>(PAGE_SHIFT-10))
#define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10))
/*
* The priority level tries to ensure that this notifier is called as
* late as possible to reduce thrashing in the shared memory pool.
*/
#define CMM_MEM_HOTPLUG_PRI 1
#define CMM_MEM_ISOLATE_PRI 15
static unsigned int delay = CMM_DEFAULT_DELAY;
static unsigned int hotplug_delay = CMM_HOTPLUG_DELAY;
static unsigned int oom_kb = CMM_OOM_KB;
static unsigned int cmm_debug = CMM_DEBUG;
static unsigned int cmm_disabled = CMM_DISABLE;
static unsigned long min_mem_mb = CMM_MIN_MEM_MB;
static struct sys_device cmm_sysdev;
MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("IBM System p Collaborative Memory Manager");
MODULE_LICENSE("GPL");
MODULE_VERSION(CMM_DRIVER_VERSION);
module_param_named(delay, delay, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(delay, "Delay (in seconds) between polls to query hypervisor paging requests. "
"[Default=" __stringify(CMM_DEFAULT_DELAY) "]");
module_param_named(hotplug_delay, hotplug_delay, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(delay, "Delay (in seconds) after memory hotplug remove "
"before loaning resumes. "
"[Default=" __stringify(CMM_HOTPLUG_DELAY) "]");
module_param_named(oom_kb, oom_kb, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(oom_kb, "Amount of memory in kb to free on OOM. "
"[Default=" __stringify(CMM_OOM_KB) "]");
module_param_named(min_mem_mb, min_mem_mb, ulong, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. "
"[Default=" __stringify(CMM_MIN_MEM_MB) "]");
module_param_named(debug, cmm_debug, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. "
"[Default=" __stringify(CMM_DEBUG) "]");
#define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long))
#define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); }
struct cmm_page_array {
struct cmm_page_array *next;
unsigned long index;
unsigned long page[CMM_NR_PAGES];
};
static unsigned long loaned_pages;
static unsigned long loaned_pages_target;
static unsigned long oom_freed_pages;
static struct cmm_page_array *cmm_page_list;
static DEFINE_SPINLOCK(cmm_lock);
static DEFINE_MUTEX(hotplug_mutex);
static int hotplug_occurred; /* protected by the hotplug mutex */
static struct task_struct *cmm_thread_ptr;
/**
* cmm_alloc_pages - Allocate pages and mark them as loaned
* @nr: number of pages to allocate
*
* Return value:
* number of pages requested to be allocated which were not
**/
static long cmm_alloc_pages(long nr)
{
struct cmm_page_array *pa, *npa;
unsigned long addr;
long rc;
cmm_dbg("Begin request for %ld pages\n", nr);
while (nr) {
/* Exit if a hotplug operation is in progress or occurred */
if (mutex_trylock(&hotplug_mutex)) {
if (hotplug_occurred) {
mutex_unlock(&hotplug_mutex);
break;
}
mutex_unlock(&hotplug_mutex);
} else {
break;
}
addr = __get_free_page(GFP_NOIO | __GFP_NOWARN |
__GFP_NORETRY | __GFP_NOMEMALLOC);
if (!addr)
break;
spin_lock(&cmm_lock);
pa = cmm_page_list;
if (!pa || pa->index >= CMM_NR_PAGES) {
/* Need a new page for the page list. */
spin_unlock(&cmm_lock);
npa = (struct cmm_page_array *)__get_free_page(
GFP_NOIO | __GFP_NOWARN |
__GFP_NORETRY | __GFP_NOMEMALLOC);
if (!npa) {
pr_info("%s: Can not allocate new page list\n", __func__);
free_page(addr);
break;
}
spin_lock(&cmm_lock);
pa = cmm_page_list;
if (!pa || pa->index >= CMM_NR_PAGES) {
npa->next = pa;
npa->index = 0;
pa = npa;
cmm_page_list = pa;
} else
free_page((unsigned long) npa);
}
if ((rc = plpar_page_set_loaned(__pa(addr)))) {
pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc);
spin_unlock(&cmm_lock);
free_page(addr);
break;
}
pa->page[pa->index++] = addr;
loaned_pages++;
totalram_pages--;
spin_unlock(&cmm_lock);
nr--;
}
cmm_dbg("End request with %ld pages unfulfilled\n", nr);
return nr;
}
/**
* cmm_free_pages - Free pages and mark them as active
* @nr: number of pages to free
*
* Return value:
* number of pages requested to be freed which were not
**/
static long cmm_free_pages(long nr)
{
struct cmm_page_array *pa;
unsigned long addr;
cmm_dbg("Begin free of %ld pages.\n", nr);
spin_lock(&cmm_lock);
pa = cmm_page_list;
while (nr) {
if (!pa || pa->index <= 0)
break;
addr = pa->page[--pa->index];
if (pa->index == 0) {
pa = pa->next;
free_page((unsigned long) cmm_page_list);
cmm_page_list = pa;
}
plpar_page_set_active(__pa(addr));
free_page(addr);
loaned_pages--;
nr--;
totalram_pages++;
}
spin_unlock(&cmm_lock);
cmm_dbg("End request with %ld pages unfulfilled\n", nr);
return nr;
}
/**
* cmm_oom_notify - OOM notifier
* @self: notifier block struct
* @dummy: not used
* @parm: returned - number of pages freed
*
* Return value:
* NOTIFY_OK
**/
static int cmm_oom_notify(struct notifier_block *self,
unsigned long dummy, void *parm)
{
unsigned long *freed = parm;
long nr = KB2PAGES(oom_kb);
cmm_dbg("OOM processing started\n");
nr = cmm_free_pages(nr);
loaned_pages_target = loaned_pages;
*freed += KB2PAGES(oom_kb) - nr;
oom_freed_pages += KB2PAGES(oom_kb) - nr;
cmm_dbg("OOM processing complete\n");
return NOTIFY_OK;
}
/**
* cmm_get_mpp - Read memory performance parameters
*
* Makes hcall to query the current page loan request from the hypervisor.
*
* Return value:
* nothing
**/
static void cmm_get_mpp(void)
{
int rc;
struct hvcall_mpp_data mpp_data;
signed long active_pages_target, page_loan_request, target;
signed long total_pages = totalram_pages + loaned_pages;
signed long min_mem_pages = (min_mem_mb * 1024 * 1024) / PAGE_SIZE;
rc = h_get_mpp(&mpp_data);
if (rc != H_SUCCESS)
return;
page_loan_request = div_s64((s64)mpp_data.loan_request, PAGE_SIZE);
target = page_loan_request + (signed long)loaned_pages;
if (target < 0 || total_pages < min_mem_pages)
target = 0;
if (target > oom_freed_pages)
target -= oom_freed_pages;
else
target = 0;
active_pages_target = total_pages - target;
if (min_mem_pages > active_pages_target)
target = total_pages - min_mem_pages;
if (target < 0)
target = 0;
loaned_pages_target = target;
cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n",
page_loan_request, loaned_pages, loaned_pages_target,
oom_freed_pages, totalram_pages);
}
static struct notifier_block cmm_oom_nb = {
.notifier_call = cmm_oom_notify
};
/**
* cmm_thread - CMM task thread
* @dummy: not used
*
* Return value:
* 0
**/
static int cmm_thread(void *dummy)
{
unsigned long timeleft;
while (1) {
timeleft = msleep_interruptible(delay * 1000);
if (kthread_should_stop() || timeleft)
break;
if (mutex_trylock(&hotplug_mutex)) {
if (hotplug_occurred) {
hotplug_occurred = 0;
mutex_unlock(&hotplug_mutex);
cmm_dbg("Hotplug operation has occurred, "
"loaning activity suspended "
"for %d seconds.\n",
hotplug_delay);
timeleft = msleep_interruptible(hotplug_delay *
1000);
if (kthread_should_stop() || timeleft)
break;
continue;
}
mutex_unlock(&hotplug_mutex);
} else {
cmm_dbg("Hotplug operation in progress, activity "
"suspended\n");
continue;
}
cmm_get_mpp();
if (loaned_pages_target > loaned_pages) {
if (cmm_alloc_pages(loaned_pages_target - loaned_pages))
loaned_pages_target = loaned_pages;
} else if (loaned_pages_target < loaned_pages)
cmm_free_pages(loaned_pages - loaned_pages_target);
}
return 0;
}
#define CMM_SHOW(name, format, args...) \
static ssize_t show_##name(struct sys_device *dev, \
struct sysdev_attribute *attr, \
char *buf) \
{ \
return sprintf(buf, format, ##args); \
} \
static SYSDEV_ATTR(name, S_IRUGO, show_##name, NULL)
CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages));
CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target));
static ssize_t show_oom_pages(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
return sprintf(buf, "%lu\n", PAGES2KB(oom_freed_pages));
}
static ssize_t store_oom_pages(struct sys_device *dev,
struct sysdev_attribute *attr,
const char *buf, size_t count)
{
unsigned long val = simple_strtoul (buf, NULL, 10);
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (val != 0)
return -EBADMSG;
oom_freed_pages = 0;
return count;
}
static SYSDEV_ATTR(oom_freed_kb, S_IWUSR| S_IRUGO,
show_oom_pages, store_oom_pages);
static struct sysdev_attribute *cmm_attrs[] = {
&attr_loaned_kb,
&attr_loaned_target_kb,
&attr_oom_freed_kb,
};
static struct sysdev_class cmm_sysdev_class = {
.name = "cmm",
};
/**
* cmm_sysfs_register - Register with sysfs
*
* Return value:
* 0 on success / other on failure
**/
static int cmm_sysfs_register(struct sys_device *sysdev)
{
int i, rc;
if ((rc = sysdev_class_register(&cmm_sysdev_class)))
return rc;
sysdev->id = 0;
sysdev->cls = &cmm_sysdev_class;
if ((rc = sysdev_register(sysdev)))
goto class_unregister;
for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) {
if ((rc = sysdev_create_file(sysdev, cmm_attrs[i])))
goto fail;
}
return 0;
fail:
while (--i >= 0)
sysdev_remove_file(sysdev, cmm_attrs[i]);
sysdev_unregister(sysdev);
class_unregister:
sysdev_class_unregister(&cmm_sysdev_class);
return rc;
}
/**
* cmm_unregister_sysfs - Unregister from sysfs
*
**/
static void cmm_unregister_sysfs(struct sys_device *sysdev)
{
int i;
for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++)
sysdev_remove_file(sysdev, cmm_attrs[i]);
sysdev_unregister(sysdev);
sysdev_class_unregister(&cmm_sysdev_class);
}
/**
* cmm_reboot_notifier - Make sure pages are not still marked as "loaned"
*
**/
static int cmm_reboot_notifier(struct notifier_block *nb,
unsigned long action, void *unused)
{
if (action == SYS_RESTART) {
if (cmm_thread_ptr)
kthread_stop(cmm_thread_ptr);
cmm_thread_ptr = NULL;
cmm_free_pages(loaned_pages);
}
return NOTIFY_DONE;
}
static struct notifier_block cmm_reboot_nb = {
.notifier_call = cmm_reboot_notifier,
};
/**
* cmm_count_pages - Count the number of pages loaned in a particular range.
*
* @arg: memory_isolate_notify structure with address range and count
*
* Return value:
* 0 on success
**/
static unsigned long cmm_count_pages(void *arg)
{
struct memory_isolate_notify *marg = arg;
struct cmm_page_array *pa;
unsigned long start = (unsigned long)pfn_to_kaddr(marg->start_pfn);
unsigned long end = start + (marg->nr_pages << PAGE_SHIFT);
unsigned long idx;
spin_lock(&cmm_lock);
pa = cmm_page_list;
while (pa) {
if ((unsigned long)pa >= start && (unsigned long)pa < end)
marg->pages_found++;
for (idx = 0; idx < pa->index; idx++)
if (pa->page[idx] >= start && pa->page[idx] < end)
marg->pages_found++;
pa = pa->next;
}
spin_unlock(&cmm_lock);
return 0;
}
/**
* cmm_memory_isolate_cb - Handle memory isolation notifier calls
* @self: notifier block struct
* @action: action to take
* @arg: struct memory_isolate_notify data for handler
*
* Return value:
* NOTIFY_OK or notifier error based on subfunction return value
**/
static int cmm_memory_isolate_cb(struct notifier_block *self,
unsigned long action, void *arg)
{
int ret = 0;
if (action == MEM_ISOLATE_COUNT)
ret = cmm_count_pages(arg);
if (ret)
ret = notifier_from_errno(ret);
else
ret = NOTIFY_OK;
return ret;
}
static struct notifier_block cmm_mem_isolate_nb = {
.notifier_call = cmm_memory_isolate_cb,
.priority = CMM_MEM_ISOLATE_PRI
};
/**
* cmm_mem_going_offline - Unloan pages where memory is to be removed
* @arg: memory_notify structure with page range to be offlined
*
* Return value:
* 0 on success
**/
static int cmm_mem_going_offline(void *arg)
{
struct memory_notify *marg = arg;
unsigned long start_page = (unsigned long)pfn_to_kaddr(marg->start_pfn);
unsigned long end_page = start_page + (marg->nr_pages << PAGE_SHIFT);
struct cmm_page_array *pa_curr, *pa_last, *npa;
unsigned long idx;
unsigned long freed = 0;
cmm_dbg("Memory going offline, searching 0x%lx (%ld pages).\n",
start_page, marg->nr_pages);
spin_lock(&cmm_lock);
/* Search the page list for pages in the range to be offlined */
pa_last = pa_curr = cmm_page_list;
while (pa_curr) {
for (idx = (pa_curr->index - 1); (idx + 1) > 0; idx--) {
if ((pa_curr->page[idx] < start_page) ||
(pa_curr->page[idx] >= end_page))
continue;
plpar_page_set_active(__pa(pa_curr->page[idx]));
free_page(pa_curr->page[idx]);
freed++;
loaned_pages--;
totalram_pages++;
pa_curr->page[idx] = pa_last->page[--pa_last->index];
if (pa_last->index == 0) {
if (pa_curr == pa_last)
pa_curr = pa_last->next;
pa_last = pa_last->next;
free_page((unsigned long)cmm_page_list);
cmm_page_list = pa_last;
continue;
}
}
pa_curr = pa_curr->next;
}
/* Search for page list structures in the range to be offlined */
pa_last = NULL;
pa_curr = cmm_page_list;
while (pa_curr) {
if (((unsigned long)pa_curr >= start_page) &&
((unsigned long)pa_curr < end_page)) {
npa = (struct cmm_page_array *)__get_free_page(
GFP_NOIO | __GFP_NOWARN |
__GFP_NORETRY | __GFP_NOMEMALLOC);
if (!npa) {
spin_unlock(&cmm_lock);
cmm_dbg("Failed to allocate memory for list "
"management. Memory hotplug "
"failed.\n");
return ENOMEM;
}
memcpy(npa, pa_curr, PAGE_SIZE);
if (pa_curr == cmm_page_list)
cmm_page_list = npa;
if (pa_last)
pa_last->next = npa;
free_page((unsigned long) pa_curr);
freed++;
pa_curr = npa;
}
pa_last = pa_curr;
pa_curr = pa_curr->next;
}
spin_unlock(&cmm_lock);
cmm_dbg("Released %ld pages in the search range.\n", freed);
return 0;
}
/**
* cmm_memory_cb - Handle memory hotplug notifier calls
* @self: notifier block struct
* @action: action to take
* @arg: struct memory_notify data for handler
*
* Return value:
* NOTIFY_OK or notifier error based on subfunction return value
*
**/
static int cmm_memory_cb(struct notifier_block *self,
unsigned long action, void *arg)
{
int ret = 0;
switch (action) {
case MEM_GOING_OFFLINE:
mutex_lock(&hotplug_mutex);
hotplug_occurred = 1;
ret = cmm_mem_going_offline(arg);
break;
case MEM_OFFLINE:
case MEM_CANCEL_OFFLINE:
mutex_unlock(&hotplug_mutex);
cmm_dbg("Memory offline operation complete.\n");
break;
case MEM_GOING_ONLINE:
case MEM_ONLINE:
case MEM_CANCEL_ONLINE:
break;
}
if (ret)
ret = notifier_from_errno(ret);
else
ret = NOTIFY_OK;
return ret;
}
static struct notifier_block cmm_mem_nb = {
.notifier_call = cmm_memory_cb,
.priority = CMM_MEM_HOTPLUG_PRI
};
/**
* cmm_init - Module initialization
*
* Return value:
* 0 on success / other on failure
**/
static int cmm_init(void)
{
int rc = -ENOMEM;
if (!firmware_has_feature(FW_FEATURE_CMO))
return -EOPNOTSUPP;
if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0)
return rc;
if ((rc = register_reboot_notifier(&cmm_reboot_nb)))
goto out_oom_notifier;
if ((rc = cmm_sysfs_register(&cmm_sysdev)))
goto out_reboot_notifier;
if (register_memory_notifier(&cmm_mem_nb) ||
register_memory_isolate_notifier(&cmm_mem_isolate_nb))
goto out_unregister_notifier;
if (cmm_disabled)
return rc;
cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
if (IS_ERR(cmm_thread_ptr)) {
rc = PTR_ERR(cmm_thread_ptr);
goto out_unregister_notifier;
}
return rc;
out_unregister_notifier:
unregister_memory_notifier(&cmm_mem_nb);
unregister_memory_isolate_notifier(&cmm_mem_isolate_nb);
cmm_unregister_sysfs(&cmm_sysdev);
out_reboot_notifier:
unregister_reboot_notifier(&cmm_reboot_nb);
out_oom_notifier:
unregister_oom_notifier(&cmm_oom_nb);
return rc;
}
/**
* cmm_exit - Module exit
*
* Return value:
* nothing
**/
static void cmm_exit(void)
{
if (cmm_thread_ptr)
kthread_stop(cmm_thread_ptr);
unregister_oom_notifier(&cmm_oom_nb);
unregister_reboot_notifier(&cmm_reboot_nb);
unregister_memory_notifier(&cmm_mem_nb);
unregister_memory_isolate_notifier(&cmm_mem_isolate_nb);
cmm_free_pages(loaned_pages);
cmm_unregister_sysfs(&cmm_sysdev);
}
/**
* cmm_set_disable - Disable/Enable CMM
*
* Return value:
* 0 on success / other on failure
**/
static int cmm_set_disable(const char *val, struct kernel_param *kp)
{
int disable = simple_strtoul(val, NULL, 10);
if (disable != 0 && disable != 1)
return -EINVAL;
if (disable && !cmm_disabled) {
if (cmm_thread_ptr)
kthread_stop(cmm_thread_ptr);
cmm_thread_ptr = NULL;
cmm_free_pages(loaned_pages);
} else if (!disable && cmm_disabled) {
cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
if (IS_ERR(cmm_thread_ptr))
return PTR_ERR(cmm_thread_ptr);
}
cmm_disabled = disable;
return 0;
}
module_param_call(disable, cmm_set_disable, param_get_uint,
&cmm_disabled, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(disable, "Disable CMM. Set to 1 to disable. "
"[Default=" __stringify(CMM_DISABLE) "]");
module_init(cmm_init);
module_exit(cmm_exit);