* Collaborative memory management interface.
*/
-#include <linux/config.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/sysctl.h>
#include <linux/ctype.h>
+#include <linux/swap.h>
+#include <linux/kthread.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
unsigned long pages[CMM_NR_PAGES];
};
-static long cmm_pages = 0;
-static long cmm_timed_pages = 0;
-static volatile long cmm_pages_target = 0;
-static volatile long cmm_timed_pages_target = 0;
-static long cmm_timeout_pages = 0;
-static long cmm_timeout_seconds = 0;
+static long cmm_pages;
+static long cmm_timed_pages;
+static volatile long cmm_pages_target;
+static volatile long cmm_timed_pages_target;
+static long cmm_timeout_pages;
+static long cmm_timeout_seconds;
-static struct cmm_page_array *cmm_page_list = NULL;
-static struct cmm_page_array *cmm_timed_page_list = NULL;
+static struct cmm_page_array *cmm_page_list;
+static struct cmm_page_array *cmm_timed_page_list;
+static DEFINE_SPINLOCK(cmm_lock);
-static unsigned long cmm_thread_active = 0;
-static struct work_struct cmm_thread_starter;
+static struct task_struct *cmm_thread_ptr;
static wait_queue_head_t cmm_thread_wait;
static struct timer_list cmm_timer;
static void cmm_set_timer(void);
static long
-cmm_strtoul(const char *cp, char **endp)
+cmm_alloc_pages(long nr, long *counter, struct cmm_page_array **list)
{
- unsigned int base = 10;
-
- if (*cp == '0') {
- base = 8;
- cp++;
- if ((*cp == 'x' || *cp == 'X') && isxdigit(cp[1])) {
- base = 16;
- cp++;
- }
- }
- return simple_strtoul(cp, endp, base);
-}
-
-static long
-cmm_alloc_pages(long pages, long *counter, struct cmm_page_array **list)
-{
- struct cmm_page_array *pa;
- unsigned long page;
+ struct cmm_page_array *pa, *npa;
+ unsigned long addr;
- pa = *list;
- while (pages) {
- page = __get_free_page(GFP_NOIO);
- if (!page)
+ while (nr) {
+ addr = __get_free_page(GFP_NOIO);
+ if (!addr)
break;
+ spin_lock(&cmm_lock);
+ pa = *list;
if (!pa || pa->index >= CMM_NR_PAGES) {
/* Need a new page for the page list. */
- pa = (struct cmm_page_array *)
+ spin_unlock(&cmm_lock);
+ npa = (struct cmm_page_array *)
__get_free_page(GFP_NOIO);
- if (!pa) {
- free_page(page);
+ if (!npa) {
+ free_page(addr);
break;
}
- pa->next = *list;
- pa->index = 0;
- *list = pa;
+ spin_lock(&cmm_lock);
+ pa = *list;
+ if (!pa || pa->index >= CMM_NR_PAGES) {
+ npa->next = pa;
+ npa->index = 0;
+ pa = npa;
+ *list = pa;
+ } else
+ free_page((unsigned long) npa);
}
- diag10(page);
- pa->pages[pa->index++] = page;
+ diag10(addr);
+ pa->pages[pa->index++] = addr;
(*counter)++;
- pages--;
+ spin_unlock(&cmm_lock);
+ nr--;
}
- return pages;
+ return nr;
}
-static void
-cmm_free_pages(long pages, long *counter, struct cmm_page_array **list)
+static long
+cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
{
struct cmm_page_array *pa;
- unsigned long page;
+ unsigned long addr;
+ spin_lock(&cmm_lock);
pa = *list;
- while (pages) {
+ while (nr) {
if (!pa || pa->index <= 0)
break;
- page = pa->pages[--pa->index];
+ addr = pa->pages[--pa->index];
if (pa->index == 0) {
pa = pa->next;
free_page((unsigned long) *list);
*list = pa;
}
- free_page(page);
+ free_page(addr);
(*counter)--;
- pages--;
+ nr--;
}
+ spin_unlock(&cmm_lock);
+ return nr;
+}
+
+static int cmm_oom_notify(struct notifier_block *self,
+ unsigned long dummy, void *parm)
+{
+ unsigned long *freed = parm;
+ long nr = 256;
+
+ nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
+ if (nr > 0)
+ nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
+ cmm_pages_target = cmm_pages;
+ cmm_timed_pages_target = cmm_timed_pages;
+ *freed += 256 - nr;
+ return NOTIFY_OK;
}
+static struct notifier_block cmm_oom_nb = {
+ .notifier_call = cmm_oom_notify
+};
+
static int
cmm_thread(void *dummy)
{
int rc;
- daemonize("cmmthread");
while (1) {
rc = wait_event_interruptible(cmm_thread_wait,
(cmm_pages != cmm_pages_target ||
- cmm_timed_pages != cmm_timed_pages_target));
- if (rc == -ERESTARTSYS) {
- /* Got kill signal. End thread. */
- clear_bit(0, &cmm_thread_active);
+ cmm_timed_pages != cmm_timed_pages_target ||
+ kthread_should_stop()));
+ if (kthread_should_stop() || rc == -ERESTARTSYS) {
cmm_pages_target = cmm_pages;
cmm_timed_pages_target = cmm_timed_pages;
break;
return 0;
}
-static void
-cmm_start_thread(void)
-{
- kernel_thread(cmm_thread, 0, 0);
-}
-
static void
cmm_kick_thread(void)
{
- if (!test_and_set_bit(0, &cmm_thread_active))
- schedule_work(&cmm_thread_starter);
wake_up(&cmm_thread_wait);
}
static void
cmm_timer_fn(unsigned long ignored)
{
- long pages;
+ long nr;
- pages = cmm_timed_pages_target - cmm_timeout_pages;
- if (pages < 0)
+ nr = cmm_timed_pages_target - cmm_timeout_pages;
+ if (nr < 0)
cmm_timed_pages_target = 0;
else
- cmm_timed_pages_target = pages;
+ cmm_timed_pages_target = nr;
cmm_kick_thread();
cmm_set_timer();
}
void
-cmm_set_pages(long pages)
+cmm_set_pages(long nr)
{
- cmm_pages_target = pages;
+ cmm_pages_target = nr;
cmm_kick_thread();
}
}
void
-cmm_add_timed_pages(long pages)
+cmm_add_timed_pages(long nr)
{
- cmm_timed_pages_target += pages;
+ cmm_timed_pages_target += nr;
cmm_kick_thread();
}
}
void
-cmm_set_timeout(long pages, long seconds)
+cmm_set_timeout(long nr, long seconds)
{
- cmm_timeout_pages = pages;
+ cmm_timeout_pages = nr;
cmm_timeout_seconds = seconds;
cmm_set_timer();
}
void __user *buffer, size_t *lenp, loff_t *ppos)
{
char buf[16], *p;
- long pages;
+ long nr;
int len;
if (!*lenp || (*ppos && !write)) {
return -EFAULT;
buf[sizeof(buf) - 1] = '\0';
cmm_skip_blanks(buf, &p);
- pages = cmm_strtoul(p, &p);
+ nr = simple_strtoul(p, &p, 0);
if (ctl == &cmm_table[0])
- cmm_set_pages(pages);
+ cmm_set_pages(nr);
else
- cmm_add_timed_pages(pages);
+ cmm_add_timed_pages(nr);
} else {
if (ctl == &cmm_table[0])
- pages = cmm_get_pages();
+ nr = cmm_get_pages();
else
- pages = cmm_get_timed_pages();
- len = sprintf(buf, "%ld\n", pages);
+ nr = cmm_get_timed_pages();
+ len = sprintf(buf, "%ld\n", nr);
if (len > *lenp)
len = *lenp;
if (copy_to_user(buffer, buf, len))
void __user *buffer, size_t *lenp, loff_t *ppos)
{
char buf[64], *p;
- long pages, seconds;
+ long nr, seconds;
int len;
if (!*lenp || (*ppos && !write)) {
return -EFAULT;
buf[sizeof(buf) - 1] = '\0';
cmm_skip_blanks(buf, &p);
- pages = cmm_strtoul(p, &p);
+ nr = simple_strtoul(p, &p, 0);
cmm_skip_blanks(p, &p);
- seconds = cmm_strtoul(p, &p);
- cmm_set_timeout(pages, seconds);
+ seconds = simple_strtoul(p, &p, 0);
+ cmm_set_timeout(nr, seconds);
} else {
len = sprintf(buf, "%ld %ld\n",
cmm_timeout_pages, cmm_timeout_seconds);
static void
cmm_smsg_target(char *from, char *msg)
{
- long pages, seconds;
+ long nr, seconds;
if (strlen(sender) > 0 && strcmp(from, sender) != 0)
return;
if (strncmp(msg, "SHRINK", 6) == 0) {
if (!cmm_skip_blanks(msg + 6, &msg))
return;
- pages = cmm_strtoul(msg, &msg);
+ nr = simple_strtoul(msg, &msg, 0);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
- cmm_set_pages(pages);
+ cmm_set_pages(nr);
} else if (strncmp(msg, "RELEASE", 7) == 0) {
if (!cmm_skip_blanks(msg + 7, &msg))
return;
- pages = cmm_strtoul(msg, &msg);
+ nr = simple_strtoul(msg, &msg, 0);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
- cmm_add_timed_pages(pages);
+ cmm_add_timed_pages(nr);
} else if (strncmp(msg, "REUSE", 5) == 0) {
if (!cmm_skip_blanks(msg + 5, &msg))
return;
- pages = cmm_strtoul(msg, &msg);
+ nr = simple_strtoul(msg, &msg, 0);
if (!cmm_skip_blanks(msg, &msg))
return;
- seconds = cmm_strtoul(msg, &msg);
+ seconds = simple_strtoul(msg, &msg, 0);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
- cmm_set_timeout(pages, seconds);
+ cmm_set_timeout(nr, seconds);
}
}
#endif
static int
cmm_init (void)
{
+ int rc = -ENOMEM;
+
#ifdef CONFIG_CMM_PROC
cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
+ if (!cmm_sysctl_header)
+ goto out;
#endif
#ifdef CONFIG_CMM_IUCV
- smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
+ rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
+ if (rc < 0)
+ goto out_smsg;
#endif
- INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, NULL);
+ rc = register_oom_notifier(&cmm_oom_nb);
+ if (rc < 0)
+ goto out_oom_notify;
init_waitqueue_head(&cmm_thread_wait);
init_timer(&cmm_timer);
- return 0;
+ cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
+ rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
+ if (!rc)
+ goto out;
+ /*
+ * kthread_create failed. undo all the stuff from above again.
+ */
+ unregister_oom_notifier(&cmm_oom_nb);
+
+out_oom_notify:
+#ifdef CONFIG_CMM_IUCV
+ smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
+out_smsg:
+#endif
+#ifdef CONFIG_CMM_PROC
+ unregister_sysctl_table(cmm_sysctl_header);
+#endif
+out:
+ return rc;
}
static void
cmm_exit(void)
{
+ kthread_stop(cmm_thread_ptr);
+ unregister_oom_notifier(&cmm_oom_nb);
cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
#ifdef CONFIG_CMM_PROC
git.samba.org / sfrench / cifs-2.6.git / blobdiff