Revision d1908362ae0b97374eb8328fbb471576332f9fb1 authored by Minchan Kim on 22 September 2010, 20:05:01 UTC, committed by Linus Torvalds on 23 September 2010, 00:22:39 UTC
M. Vefa Bicakci reported 2.6.35 kernel hang up when hibernation on his 32bit 3GB mem machine. (https://bugzilla.kernel.org/show_bug.cgi?id=16771). Also he bisected the regression to commit bb21c7ce18eff8e6e7877ca1d06c6db719376e3c Author: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Date: Fri Jun 4 14:15:05 2010 -0700 vmscan: fix do_try_to_free_pages() return value when priority==0 reclaim failure At first impression, this seemed very strange because the above commit only chenged function return value and hibernate_preallocate_memory() ignore return value of shrink_all_memory(). But it's related. Now, page allocation from hibernation code may enter infinite loop if the system has highmem. The reasons are that vmscan don't care enough OOM case when oom_killer_disabled. The problem sequence is following as. 1. hibernation 2. oom_disable 3. alloc_pages 4. do_try_to_free_pages if (scanning_global_lru(sc) && !all_unreclaimable) return 1; If kswapd is not freozen, it would set zone->all_unreclaimable to 1 and then shrink_zones maybe return true(ie, all_unreclaimable is true). So at last, alloc_pages could go to _nopage_. If it is, it should have no problem. This patch adds all_unreclaimable check to protect in direct reclaim path, too. It can care of hibernation OOM case and help bailout all_unreclaimable case slightly. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reported-by: M. Vefa Bicakci <bicave@superonline.com> Reported-by: <caiqian@redhat.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: <caiqian@redhat.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent eba93fc
sysctl_check.c
#include <linux/stat.h>
#include <linux/sysctl.h>
#include "../fs/xfs/linux-2.6/xfs_sysctl.h"
#include <linux/sunrpc/debug.h>
#include <linux/string.h>
#include <net/ip_vs.h>
static int sysctl_depth(struct ctl_table *table)
{
struct ctl_table *tmp;
int depth;
depth = 0;
for (tmp = table; tmp->parent; tmp = tmp->parent)
depth++;
return depth;
}
static struct ctl_table *sysctl_parent(struct ctl_table *table, int n)
{
int i;
for (i = 0; table && i < n; i++)
table = table->parent;
return table;
}
static void sysctl_print_path(struct ctl_table *table)
{
struct ctl_table *tmp;
int depth, i;
depth = sysctl_depth(table);
if (table->procname) {
for (i = depth; i >= 0; i--) {
tmp = sysctl_parent(table, i);
printk("/%s", tmp->procname?tmp->procname:"");
}
}
printk(" ");
}
static struct ctl_table *sysctl_check_lookup(struct nsproxy *namespaces,
struct ctl_table *table)
{
struct ctl_table_header *head;
struct ctl_table *ref, *test;
int depth, cur_depth;
depth = sysctl_depth(table);
for (head = __sysctl_head_next(namespaces, NULL); head;
head = __sysctl_head_next(namespaces, head)) {
cur_depth = depth;
ref = head->ctl_table;
repeat:
test = sysctl_parent(table, cur_depth);
for (; ref->procname; ref++) {
int match = 0;
if (cur_depth && !ref->child)
continue;
if (test->procname && ref->procname &&
(strcmp(test->procname, ref->procname) == 0))
match++;
if (match) {
if (cur_depth != 0) {
cur_depth--;
ref = ref->child;
goto repeat;
}
goto out;
}
}
}
ref = NULL;
out:
sysctl_head_finish(head);
return ref;
}
static void set_fail(const char **fail, struct ctl_table *table, const char *str)
{
if (*fail) {
printk(KERN_ERR "sysctl table check failed: ");
sysctl_print_path(table);
printk(" %s\n", *fail);
dump_stack();
}
*fail = str;
}
static void sysctl_check_leaf(struct nsproxy *namespaces,
struct ctl_table *table, const char **fail)
{
struct ctl_table *ref;
ref = sysctl_check_lookup(namespaces, table);
if (ref && (ref != table))
set_fail(fail, table, "Sysctl already exists");
}
int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table)
{
int error = 0;
for (; table->procname; table++) {
const char *fail = NULL;
if (table->parent) {
if (table->procname && !table->parent->procname)
set_fail(&fail, table, "Parent without procname");
}
if (!table->procname)
set_fail(&fail, table, "No procname");
if (table->child) {
if (table->data)
set_fail(&fail, table, "Directory with data?");
if (table->maxlen)
set_fail(&fail, table, "Directory with maxlen?");
if ((table->mode & (S_IRUGO|S_IXUGO)) != table->mode)
set_fail(&fail, table, "Writable sysctl directory");
if (table->proc_handler)
set_fail(&fail, table, "Directory with proc_handler");
if (table->extra1)
set_fail(&fail, table, "Directory with extra1");
if (table->extra2)
set_fail(&fail, table, "Directory with extra2");
} else {
if ((table->proc_handler == proc_dostring) ||
(table->proc_handler == proc_dointvec) ||
(table->proc_handler == proc_dointvec_minmax) ||
(table->proc_handler == proc_dointvec_jiffies) ||
(table->proc_handler == proc_dointvec_userhz_jiffies) ||
(table->proc_handler == proc_dointvec_ms_jiffies) ||
(table->proc_handler == proc_doulongvec_minmax) ||
(table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
if (!table->data)
set_fail(&fail, table, "No data");
if (!table->maxlen)
set_fail(&fail, table, "No maxlen");
}
if ((table->proc_handler == proc_doulongvec_minmax) ||
(table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
if (table->maxlen > sizeof (unsigned long)) {
if (!table->extra1)
set_fail(&fail, table, "No min");
if (!table->extra2)
set_fail(&fail, table, "No max");
}
}
#ifdef CONFIG_PROC_SYSCTL
if (table->procname && !table->proc_handler)
set_fail(&fail, table, "No proc_handler");
#endif
#if 0
if (!table->procname && table->proc_handler)
set_fail(&fail, table, "proc_handler without procname");
#endif
sysctl_check_leaf(namespaces, table, &fail);
}
if (table->mode > 0777)
set_fail(&fail, table, "bogus .mode");
if (fail) {
set_fail(&fail, table, NULL);
error = -EINVAL;
}
if (table->child)
error |= sysctl_check_table(namespaces, table->child);
}
return error;
}
Computing file changes ...