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444 lines
9.7 KiB
444 lines
9.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Collaborative memory management interface. |
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* |
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* Copyright IBM Corp 2003, 2010 |
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* Author(s): Martin Schwidefsky <[email protected]>, |
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* |
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*/ |
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#include <linux/errno.h> |
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#include <linux/fs.h> |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/gfp.h> |
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#include <linux/sched.h> |
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#include <linux/sysctl.h> |
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#include <linux/ctype.h> |
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#include <linux/swap.h> |
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#include <linux/kthread.h> |
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#include <linux/oom.h> |
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#include <linux/uaccess.h> |
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#include <asm/diag.h> |
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#ifdef CONFIG_CMM_IUCV |
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static char *cmm_default_sender = "VMRMSVM"; |
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#endif |
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static char *sender; |
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module_param(sender, charp, 0400); |
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MODULE_PARM_DESC(sender, |
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"Guest name that may send SMSG messages (default VMRMSVM)"); |
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#include "../../../drivers/s390/net/smsgiucv.h" |
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#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2) |
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struct cmm_page_array { |
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struct cmm_page_array *next; |
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unsigned long index; |
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unsigned long pages[CMM_NR_PAGES]; |
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}; |
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static long cmm_pages; |
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static long cmm_timed_pages; |
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static volatile long cmm_pages_target; |
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static volatile long cmm_timed_pages_target; |
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static long cmm_timeout_pages; |
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static long cmm_timeout_seconds; |
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static struct cmm_page_array *cmm_page_list; |
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static struct cmm_page_array *cmm_timed_page_list; |
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static DEFINE_SPINLOCK(cmm_lock); |
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static struct task_struct *cmm_thread_ptr; |
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static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait); |
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static void cmm_timer_fn(struct timer_list *); |
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static void cmm_set_timer(void); |
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static DEFINE_TIMER(cmm_timer, cmm_timer_fn); |
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static long cmm_alloc_pages(long nr, long *counter, |
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struct cmm_page_array **list) |
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{ |
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struct cmm_page_array *pa, *npa; |
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unsigned long addr; |
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while (nr) { |
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addr = __get_free_page(GFP_NOIO); |
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if (!addr) |
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break; |
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spin_lock(&cmm_lock); |
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pa = *list; |
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if (!pa || pa->index >= CMM_NR_PAGES) { |
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/* Need a new page for the page list. */ |
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spin_unlock(&cmm_lock); |
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npa = (struct cmm_page_array *) |
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__get_free_page(GFP_NOIO); |
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if (!npa) { |
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free_page(addr); |
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break; |
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} |
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spin_lock(&cmm_lock); |
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pa = *list; |
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if (!pa || pa->index >= CMM_NR_PAGES) { |
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npa->next = pa; |
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npa->index = 0; |
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pa = npa; |
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*list = pa; |
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} else |
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free_page((unsigned long) npa); |
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} |
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diag10_range(addr >> PAGE_SHIFT, 1); |
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pa->pages[pa->index++] = addr; |
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(*counter)++; |
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spin_unlock(&cmm_lock); |
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nr--; |
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} |
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return nr; |
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} |
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static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list) |
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{ |
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struct cmm_page_array *pa; |
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unsigned long addr; |
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spin_lock(&cmm_lock); |
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pa = *list; |
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while (nr) { |
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if (!pa || pa->index <= 0) |
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break; |
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addr = pa->pages[--pa->index]; |
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if (pa->index == 0) { |
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pa = pa->next; |
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free_page((unsigned long) *list); |
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*list = pa; |
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} |
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free_page(addr); |
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(*counter)--; |
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nr--; |
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} |
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spin_unlock(&cmm_lock); |
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return nr; |
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} |
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static int cmm_oom_notify(struct notifier_block *self, |
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unsigned long dummy, void *parm) |
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{ |
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unsigned long *freed = parm; |
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long nr = 256; |
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nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list); |
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if (nr > 0) |
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nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list); |
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cmm_pages_target = cmm_pages; |
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cmm_timed_pages_target = cmm_timed_pages; |
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*freed += 256 - nr; |
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return NOTIFY_OK; |
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} |
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static struct notifier_block cmm_oom_nb = { |
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.notifier_call = cmm_oom_notify, |
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}; |
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static int cmm_thread(void *dummy) |
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{ |
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int rc; |
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while (1) { |
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rc = wait_event_interruptible(cmm_thread_wait, |
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cmm_pages != cmm_pages_target || |
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cmm_timed_pages != cmm_timed_pages_target || |
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kthread_should_stop()); |
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if (kthread_should_stop() || rc == -ERESTARTSYS) { |
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cmm_pages_target = cmm_pages; |
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cmm_timed_pages_target = cmm_timed_pages; |
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break; |
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} |
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if (cmm_pages_target > cmm_pages) { |
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if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list)) |
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cmm_pages_target = cmm_pages; |
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} else if (cmm_pages_target < cmm_pages) { |
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cmm_free_pages(1, &cmm_pages, &cmm_page_list); |
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} |
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if (cmm_timed_pages_target > cmm_timed_pages) { |
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if (cmm_alloc_pages(1, &cmm_timed_pages, |
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&cmm_timed_page_list)) |
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cmm_timed_pages_target = cmm_timed_pages; |
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} else if (cmm_timed_pages_target < cmm_timed_pages) { |
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cmm_free_pages(1, &cmm_timed_pages, |
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&cmm_timed_page_list); |
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} |
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if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer)) |
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cmm_set_timer(); |
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} |
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return 0; |
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} |
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static void cmm_kick_thread(void) |
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{ |
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wake_up(&cmm_thread_wait); |
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} |
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static void cmm_set_timer(void) |
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{ |
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if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) { |
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if (timer_pending(&cmm_timer)) |
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del_timer(&cmm_timer); |
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return; |
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} |
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mod_timer(&cmm_timer, jiffies + msecs_to_jiffies(cmm_timeout_seconds * MSEC_PER_SEC)); |
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} |
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static void cmm_timer_fn(struct timer_list *unused) |
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{ |
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long nr; |
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nr = cmm_timed_pages_target - cmm_timeout_pages; |
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if (nr < 0) |
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cmm_timed_pages_target = 0; |
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else |
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cmm_timed_pages_target = nr; |
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cmm_kick_thread(); |
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cmm_set_timer(); |
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} |
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static void cmm_set_pages(long nr) |
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{ |
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cmm_pages_target = nr; |
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cmm_kick_thread(); |
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} |
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static long cmm_get_pages(void) |
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{ |
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return cmm_pages; |
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} |
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static void cmm_add_timed_pages(long nr) |
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{ |
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cmm_timed_pages_target += nr; |
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cmm_kick_thread(); |
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} |
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static long cmm_get_timed_pages(void) |
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{ |
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return cmm_timed_pages; |
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} |
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static void cmm_set_timeout(long nr, long seconds) |
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{ |
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cmm_timeout_pages = nr; |
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cmm_timeout_seconds = seconds; |
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cmm_set_timer(); |
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} |
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static int cmm_skip_blanks(char *cp, char **endp) |
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{ |
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char *str; |
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for (str = cp; *str == ' ' || *str == '\t'; str++) |
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; |
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*endp = str; |
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return str != cp; |
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} |
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static int cmm_pages_handler(struct ctl_table *ctl, int write, |
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void *buffer, size_t *lenp, loff_t *ppos) |
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{ |
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long nr = cmm_get_pages(); |
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struct ctl_table ctl_entry = { |
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.procname = ctl->procname, |
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.data = &nr, |
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.maxlen = sizeof(long), |
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}; |
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int rc; |
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rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos); |
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if (rc < 0 || !write) |
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return rc; |
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cmm_set_pages(nr); |
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return 0; |
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} |
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static int cmm_timed_pages_handler(struct ctl_table *ctl, int write, |
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void *buffer, size_t *lenp, |
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loff_t *ppos) |
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{ |
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long nr = cmm_get_timed_pages(); |
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struct ctl_table ctl_entry = { |
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.procname = ctl->procname, |
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.data = &nr, |
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.maxlen = sizeof(long), |
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}; |
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int rc; |
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rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos); |
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if (rc < 0 || !write) |
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return rc; |
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cmm_add_timed_pages(nr); |
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return 0; |
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} |
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static int cmm_timeout_handler(struct ctl_table *ctl, int write, |
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void *buffer, size_t *lenp, loff_t *ppos) |
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{ |
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char buf[64], *p; |
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long nr, seconds; |
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unsigned int len; |
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if (!*lenp || (*ppos && !write)) { |
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*lenp = 0; |
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return 0; |
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} |
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if (write) { |
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len = min(*lenp, sizeof(buf)); |
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memcpy(buf, buffer, len); |
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buf[len - 1] = '\0'; |
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cmm_skip_blanks(buf, &p); |
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nr = simple_strtoul(p, &p, 0); |
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cmm_skip_blanks(p, &p); |
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seconds = simple_strtoul(p, &p, 0); |
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cmm_set_timeout(nr, seconds); |
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*ppos += *lenp; |
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} else { |
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len = sprintf(buf, "%ld %ld\n", |
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cmm_timeout_pages, cmm_timeout_seconds); |
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if (len > *lenp) |
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len = *lenp; |
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memcpy(buffer, buf, len); |
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*lenp = len; |
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*ppos += len; |
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} |
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return 0; |
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} |
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static struct ctl_table cmm_table[] = { |
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{ |
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.procname = "cmm_pages", |
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.mode = 0644, |
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.proc_handler = cmm_pages_handler, |
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}, |
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{ |
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.procname = "cmm_timed_pages", |
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.mode = 0644, |
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.proc_handler = cmm_timed_pages_handler, |
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}, |
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{ |
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.procname = "cmm_timeout", |
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.mode = 0644, |
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.proc_handler = cmm_timeout_handler, |
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}, |
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{ } |
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}; |
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static struct ctl_table cmm_dir_table[] = { |
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{ |
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.procname = "vm", |
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.maxlen = 0, |
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.mode = 0555, |
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.child = cmm_table, |
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}, |
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{ } |
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}; |
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#ifdef CONFIG_CMM_IUCV |
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#define SMSG_PREFIX "CMM" |
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static void cmm_smsg_target(const char *from, char *msg) |
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{ |
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long nr, seconds; |
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if (strlen(sender) > 0 && strcmp(from, sender) != 0) |
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return; |
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if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg)) |
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return; |
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if (strncmp(msg, "SHRINK", 6) == 0) { |
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if (!cmm_skip_blanks(msg + 6, &msg)) |
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return; |
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nr = simple_strtoul(msg, &msg, 0); |
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cmm_skip_blanks(msg, &msg); |
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if (*msg == '\0') |
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cmm_set_pages(nr); |
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} else if (strncmp(msg, "RELEASE", 7) == 0) { |
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if (!cmm_skip_blanks(msg + 7, &msg)) |
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return; |
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nr = simple_strtoul(msg, &msg, 0); |
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cmm_skip_blanks(msg, &msg); |
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if (*msg == '\0') |
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cmm_add_timed_pages(nr); |
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} else if (strncmp(msg, "REUSE", 5) == 0) { |
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if (!cmm_skip_blanks(msg + 5, &msg)) |
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return; |
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nr = simple_strtoul(msg, &msg, 0); |
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if (!cmm_skip_blanks(msg, &msg)) |
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return; |
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seconds = simple_strtoul(msg, &msg, 0); |
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cmm_skip_blanks(msg, &msg); |
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if (*msg == '\0') |
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cmm_set_timeout(nr, seconds); |
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} |
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} |
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#endif |
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static struct ctl_table_header *cmm_sysctl_header; |
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static int __init cmm_init(void) |
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{ |
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int rc = -ENOMEM; |
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cmm_sysctl_header = register_sysctl_table(cmm_dir_table); |
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if (!cmm_sysctl_header) |
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goto out_sysctl; |
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#ifdef CONFIG_CMM_IUCV |
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/* convert sender to uppercase characters */ |
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if (sender) { |
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int len = strlen(sender); |
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while (len--) |
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sender[len] = toupper(sender[len]); |
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} else { |
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sender = cmm_default_sender; |
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} |
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rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); |
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if (rc < 0) |
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goto out_smsg; |
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#endif |
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rc = register_oom_notifier(&cmm_oom_nb); |
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if (rc < 0) |
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goto out_oom_notify; |
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cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); |
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if (!IS_ERR(cmm_thread_ptr)) |
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return 0; |
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rc = PTR_ERR(cmm_thread_ptr); |
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unregister_oom_notifier(&cmm_oom_nb); |
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out_oom_notify: |
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#ifdef CONFIG_CMM_IUCV |
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smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); |
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out_smsg: |
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#endif |
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unregister_sysctl_table(cmm_sysctl_header); |
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out_sysctl: |
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del_timer_sync(&cmm_timer); |
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return rc; |
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} |
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module_init(cmm_init); |
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static void __exit cmm_exit(void) |
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{ |
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unregister_sysctl_table(cmm_sysctl_header); |
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#ifdef CONFIG_CMM_IUCV |
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smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); |
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#endif |
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unregister_oom_notifier(&cmm_oom_nb); |
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kthread_stop(cmm_thread_ptr); |
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del_timer_sync(&cmm_timer); |
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cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); |
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cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); |
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} |
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module_exit(cmm_exit); |
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MODULE_LICENSE("GPL");
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