linux_dsm_epyc7002/arch/s390/mm/cmm.c
Eric W. Biederman 0b4d414714 [PATCH] sysctl: remove insert_at_head from register_sysctl
The semantic effect of insert_at_head is that it would allow new registered
sysctl entries to override existing sysctl entries of the same name.  Which is
pain for caching and the proc interface never implemented.

I have done an audit and discovered that none of the current users of
register_sysctl care as (excpet for directories) they do not register
duplicate sysctl entries.

So this patch simply removes the support for overriding existing entries in
the sys_sysctl interface since no one uses it or cares and it makes future
enhancments harder.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00

481 lines
10 KiB
C

/*
* arch/s390/mm/cmm.c
*
* S390 version
* Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* Collaborative memory management interface.
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/module.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>
static char *sender = "VMRMSVM";
module_param(sender, charp, 0400);
MODULE_PARM_DESC(sender,
"Guest name that may send SMSG messages (default VMRMSVM)");
#include "../../../drivers/s390/net/smsgiucv.h"
#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
struct cmm_page_array {
struct cmm_page_array *next;
unsigned long index;
unsigned long pages[CMM_NR_PAGES];
};
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;
static struct cmm_page_array *cmm_timed_page_list;
static DEFINE_SPINLOCK(cmm_lock);
static struct task_struct *cmm_thread_ptr;
static wait_queue_head_t cmm_thread_wait;
static struct timer_list cmm_timer;
static void cmm_timer_fn(unsigned long);
static void cmm_set_timer(void);
static long
cmm_alloc_pages(long nr, long *counter, struct cmm_page_array **list)
{
struct cmm_page_array *pa, *npa;
unsigned long addr;
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. */
spin_unlock(&cmm_lock);
npa = (struct cmm_page_array *)
__get_free_page(GFP_NOIO);
if (!npa) {
free_page(addr);
break;
}
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(addr);
pa->pages[pa->index++] = addr;
(*counter)++;
spin_unlock(&cmm_lock);
nr--;
}
return nr;
}
static long
cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
{
struct cmm_page_array *pa;
unsigned long addr;
spin_lock(&cmm_lock);
pa = *list;
while (nr) {
if (!pa || pa->index <= 0)
break;
addr = pa->pages[--pa->index];
if (pa->index == 0) {
pa = pa->next;
free_page((unsigned long) *list);
*list = pa;
}
free_page(addr);
(*counter)--;
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;
while (1) {
rc = wait_event_interruptible(cmm_thread_wait,
(cmm_pages != cmm_pages_target ||
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;
}
if (cmm_pages_target > cmm_pages) {
if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
cmm_pages_target = cmm_pages;
} else if (cmm_pages_target < cmm_pages) {
cmm_free_pages(1, &cmm_pages, &cmm_page_list);
}
if (cmm_timed_pages_target > cmm_timed_pages) {
if (cmm_alloc_pages(1, &cmm_timed_pages,
&cmm_timed_page_list))
cmm_timed_pages_target = cmm_timed_pages;
} else if (cmm_timed_pages_target < cmm_timed_pages) {
cmm_free_pages(1, &cmm_timed_pages,
&cmm_timed_page_list);
}
if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
cmm_set_timer();
}
return 0;
}
static void
cmm_kick_thread(void)
{
wake_up(&cmm_thread_wait);
}
static void
cmm_set_timer(void)
{
if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
if (timer_pending(&cmm_timer))
del_timer(&cmm_timer);
return;
}
if (timer_pending(&cmm_timer)) {
if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
return;
}
cmm_timer.function = cmm_timer_fn;
cmm_timer.data = 0;
cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
add_timer(&cmm_timer);
}
static void
cmm_timer_fn(unsigned long ignored)
{
long nr;
nr = cmm_timed_pages_target - cmm_timeout_pages;
if (nr < 0)
cmm_timed_pages_target = 0;
else
cmm_timed_pages_target = nr;
cmm_kick_thread();
cmm_set_timer();
}
void
cmm_set_pages(long nr)
{
cmm_pages_target = nr;
cmm_kick_thread();
}
long
cmm_get_pages(void)
{
return cmm_pages;
}
void
cmm_add_timed_pages(long nr)
{
cmm_timed_pages_target += nr;
cmm_kick_thread();
}
long
cmm_get_timed_pages(void)
{
return cmm_timed_pages;
}
void
cmm_set_timeout(long nr, long seconds)
{
cmm_timeout_pages = nr;
cmm_timeout_seconds = seconds;
cmm_set_timer();
}
static int
cmm_skip_blanks(char *cp, char **endp)
{
char *str;
for (str = cp; *str == ' ' || *str == '\t'; str++);
*endp = str;
return str != cp;
}
#ifdef CONFIG_CMM_PROC
static struct ctl_table cmm_table[];
static int
cmm_pages_handler(ctl_table *ctl, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
char buf[16], *p;
long nr;
int len;
if (!*lenp || (*ppos && !write)) {
*lenp = 0;
return 0;
}
if (write) {
len = *lenp;
if (copy_from_user(buf, buffer,
len > sizeof(buf) ? sizeof(buf) : len))
return -EFAULT;
buf[sizeof(buf) - 1] = '\0';
cmm_skip_blanks(buf, &p);
nr = simple_strtoul(p, &p, 0);
if (ctl == &cmm_table[0])
cmm_set_pages(nr);
else
cmm_add_timed_pages(nr);
} else {
if (ctl == &cmm_table[0])
nr = cmm_get_pages();
else
nr = cmm_get_timed_pages();
len = sprintf(buf, "%ld\n", nr);
if (len > *lenp)
len = *lenp;
if (copy_to_user(buffer, buf, len))
return -EFAULT;
}
*lenp = len;
*ppos += len;
return 0;
}
static int
cmm_timeout_handler(ctl_table *ctl, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
char buf[64], *p;
long nr, seconds;
int len;
if (!*lenp || (*ppos && !write)) {
*lenp = 0;
return 0;
}
if (write) {
len = *lenp;
if (copy_from_user(buf, buffer,
len > sizeof(buf) ? sizeof(buf) : len))
return -EFAULT;
buf[sizeof(buf) - 1] = '\0';
cmm_skip_blanks(buf, &p);
nr = simple_strtoul(p, &p, 0);
cmm_skip_blanks(p, &p);
seconds = simple_strtoul(p, &p, 0);
cmm_set_timeout(nr, seconds);
} else {
len = sprintf(buf, "%ld %ld\n",
cmm_timeout_pages, cmm_timeout_seconds);
if (len > *lenp)
len = *lenp;
if (copy_to_user(buffer, buf, len))
return -EFAULT;
}
*lenp = len;
*ppos += len;
return 0;
}
static struct ctl_table cmm_table[] = {
{
.ctl_name = VM_CMM_PAGES,
.procname = "cmm_pages",
.mode = 0644,
.proc_handler = &cmm_pages_handler,
},
{
.ctl_name = VM_CMM_TIMED_PAGES,
.procname = "cmm_timed_pages",
.mode = 0644,
.proc_handler = &cmm_pages_handler,
},
{
.ctl_name = VM_CMM_TIMEOUT,
.procname = "cmm_timeout",
.mode = 0644,
.proc_handler = &cmm_timeout_handler,
},
{ .ctl_name = 0 }
};
static struct ctl_table cmm_dir_table[] = {
{
.ctl_name = CTL_VM,
.procname = "vm",
.maxlen = 0,
.mode = 0555,
.child = cmm_table,
},
{ .ctl_name = 0 }
};
#endif
#ifdef CONFIG_CMM_IUCV
#define SMSG_PREFIX "CMM"
static void
cmm_smsg_target(char *from, char *msg)
{
long nr, seconds;
if (strlen(sender) > 0 && strcmp(from, sender) != 0)
return;
if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
return;
if (strncmp(msg, "SHRINK", 6) == 0) {
if (!cmm_skip_blanks(msg + 6, &msg))
return;
nr = simple_strtoul(msg, &msg, 0);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
cmm_set_pages(nr);
} else if (strncmp(msg, "RELEASE", 7) == 0) {
if (!cmm_skip_blanks(msg + 7, &msg))
return;
nr = simple_strtoul(msg, &msg, 0);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
cmm_add_timed_pages(nr);
} else if (strncmp(msg, "REUSE", 5) == 0) {
if (!cmm_skip_blanks(msg + 5, &msg))
return;
nr = simple_strtoul(msg, &msg, 0);
if (!cmm_skip_blanks(msg, &msg))
return;
seconds = simple_strtoul(msg, &msg, 0);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
cmm_set_timeout(nr, seconds);
}
}
#endif
static struct ctl_table_header *cmm_sysctl_header;
static int
cmm_init (void)
{
int rc = -ENOMEM;
#ifdef CONFIG_CMM_PROC
cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
if (!cmm_sysctl_header)
goto out;
#endif
#ifdef CONFIG_CMM_IUCV
rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
if (rc < 0)
goto out_smsg;
#endif
rc = register_oom_notifier(&cmm_oom_nb);
if (rc < 0)
goto out_oom_notify;
init_waitqueue_head(&cmm_thread_wait);
init_timer(&cmm_timer);
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
unregister_sysctl_table(cmm_sysctl_header);
#endif
#ifdef CONFIG_CMM_IUCV
smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
#endif
}
module_init(cmm_init);
module_exit(cmm_exit);
EXPORT_SYMBOL(cmm_set_pages);
EXPORT_SYMBOL(cmm_get_pages);
EXPORT_SYMBOL(cmm_add_timed_pages);
EXPORT_SYMBOL(cmm_get_timed_pages);
EXPORT_SYMBOL(cmm_set_timeout);
MODULE_LICENSE("GPL");