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-rw-r--r--kernel/cpuset.c104
1 files changed, 98 insertions, 6 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 44d13c246e5..38f18b33de6 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -4,15 +4,14 @@
* Processor and Memory placement constraints for sets of tasks.
*
* Copyright (C) 2003 BULL SA.
- * Copyright (C) 2004 Silicon Graphics, Inc.
+ * Copyright (C) 2004-2006 Silicon Graphics, Inc.
*
* Portions derived from Patrick Mochel's sysfs code.
* sysfs is Copyright (c) 2001-3 Patrick Mochel
- * Portions Copyright (c) 2004 Silicon Graphics, Inc.
*
- * 2003-10-10 Written by Simon Derr <simon.derr@bull.net>
+ * 2003-10-10 Written by Simon Derr.
* 2003-10-22 Updates by Stephen Hemminger.
- * 2004 May-July Rework by Paul Jackson <pj@sgi.com>
+ * 2004 May-July Rework by Paul Jackson.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of the Linux
@@ -108,7 +107,9 @@ typedef enum {
CS_MEM_EXCLUSIVE,
CS_MEMORY_MIGRATE,
CS_REMOVED,
- CS_NOTIFY_ON_RELEASE
+ CS_NOTIFY_ON_RELEASE,
+ CS_SPREAD_PAGE,
+ CS_SPREAD_SLAB,
} cpuset_flagbits_t;
/* convenient tests for these bits */
@@ -137,6 +138,16 @@ static inline int is_memory_migrate(const struct cpuset *cs)
return test_bit(CS_MEMORY_MIGRATE, &cs->flags);
}
+static inline int is_spread_page(const struct cpuset *cs)
+{
+ return test_bit(CS_SPREAD_PAGE, &cs->flags);
+}
+
+static inline int is_spread_slab(const struct cpuset *cs)
+{
+ return test_bit(CS_SPREAD_SLAB, &cs->flags);
+}
+
/*
* Increment this atomic integer everytime any cpuset changes its
* mems_allowed value. Users of cpusets can track this generation
@@ -657,6 +668,14 @@ void cpuset_update_task_memory_state(void)
cs = tsk->cpuset; /* Maybe changed when task not locked */
guarantee_online_mems(cs, &tsk->mems_allowed);
tsk->cpuset_mems_generation = cs->mems_generation;
+ if (is_spread_page(cs))
+ tsk->flags |= PF_SPREAD_PAGE;
+ else
+ tsk->flags &= ~PF_SPREAD_PAGE;
+ if (is_spread_slab(cs))
+ tsk->flags |= PF_SPREAD_SLAB;
+ else
+ tsk->flags &= ~PF_SPREAD_SLAB;
task_unlock(tsk);
mutex_unlock(&callback_mutex);
mpol_rebind_task(tsk, &tsk->mems_allowed);
@@ -956,7 +975,8 @@ static int update_memory_pressure_enabled(struct cpuset *cs, char *buf)
/*
* update_flag - read a 0 or a 1 in a file and update associated flag
* bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE,
- * CS_NOTIFY_ON_RELEASE, CS_MEMORY_MIGRATE)
+ * CS_NOTIFY_ON_RELEASE, CS_MEMORY_MIGRATE,
+ * CS_SPREAD_PAGE, CS_SPREAD_SLAB)
* cs: the cpuset to update
* buf: the buffer where we read the 0 or 1
*
@@ -1187,6 +1207,8 @@ typedef enum {
FILE_NOTIFY_ON_RELEASE,
FILE_MEMORY_PRESSURE_ENABLED,
FILE_MEMORY_PRESSURE,
+ FILE_SPREAD_PAGE,
+ FILE_SPREAD_SLAB,
FILE_TASKLIST,
} cpuset_filetype_t;
@@ -1246,6 +1268,14 @@ static ssize_t cpuset_common_file_write(struct file *file, const char __user *us
case FILE_MEMORY_PRESSURE:
retval = -EACCES;
break;
+ case FILE_SPREAD_PAGE:
+ retval = update_flag(CS_SPREAD_PAGE, cs, buffer);
+ cs->mems_generation = atomic_inc_return(&cpuset_mems_generation);
+ break;
+ case FILE_SPREAD_SLAB:
+ retval = update_flag(CS_SPREAD_SLAB, cs, buffer);
+ cs->mems_generation = atomic_inc_return(&cpuset_mems_generation);
+ break;
case FILE_TASKLIST:
retval = attach_task(cs, buffer, &pathbuf);
break;
@@ -1355,6 +1385,12 @@ static ssize_t cpuset_common_file_read(struct file *file, char __user *buf,
case FILE_MEMORY_PRESSURE:
s += sprintf(s, "%d", fmeter_getrate(&cs->fmeter));
break;
+ case FILE_SPREAD_PAGE:
+ *s++ = is_spread_page(cs) ? '1' : '0';
+ break;
+ case FILE_SPREAD_SLAB:
+ *s++ = is_spread_slab(cs) ? '1' : '0';
+ break;
default:
retval = -EINVAL;
goto out;
@@ -1718,6 +1754,16 @@ static struct cftype cft_memory_pressure = {
.private = FILE_MEMORY_PRESSURE,
};
+static struct cftype cft_spread_page = {
+ .name = "memory_spread_page",
+ .private = FILE_SPREAD_PAGE,
+};
+
+static struct cftype cft_spread_slab = {
+ .name = "memory_spread_slab",
+ .private = FILE_SPREAD_SLAB,
+};
+
static int cpuset_populate_dir(struct dentry *cs_dentry)
{
int err;
@@ -1736,6 +1782,10 @@ static int cpuset_populate_dir(struct dentry *cs_dentry)
return err;
if ((err = cpuset_add_file(cs_dentry, &cft_memory_pressure)) < 0)
return err;
+ if ((err = cpuset_add_file(cs_dentry, &cft_spread_page)) < 0)
+ return err;
+ if ((err = cpuset_add_file(cs_dentry, &cft_spread_slab)) < 0)
+ return err;
if ((err = cpuset_add_file(cs_dentry, &cft_tasks)) < 0)
return err;
return 0;
@@ -1764,6 +1814,10 @@ static long cpuset_create(struct cpuset *parent, const char *name, int mode)
cs->flags = 0;
if (notify_on_release(parent))
set_bit(CS_NOTIFY_ON_RELEASE, &cs->flags);
+ if (is_spread_page(parent))
+ set_bit(CS_SPREAD_PAGE, &cs->flags);
+ if (is_spread_slab(parent))
+ set_bit(CS_SPREAD_SLAB, &cs->flags);
cs->cpus_allowed = CPU_MASK_NONE;
cs->mems_allowed = NODE_MASK_NONE;
atomic_set(&cs->count, 0);
@@ -2201,6 +2255,44 @@ void cpuset_unlock(void)
}
/**
+ * cpuset_mem_spread_node() - On which node to begin search for a page
+ *
+ * If a task is marked PF_SPREAD_PAGE or PF_SPREAD_SLAB (as for
+ * tasks in a cpuset with is_spread_page or is_spread_slab set),
+ * and if the memory allocation used cpuset_mem_spread_node()
+ * to determine on which node to start looking, as it will for
+ * certain page cache or slab cache pages such as used for file
+ * system buffers and inode caches, then instead of starting on the
+ * local node to look for a free page, rather spread the starting
+ * node around the tasks mems_allowed nodes.
+ *
+ * We don't have to worry about the returned node being offline
+ * because "it can't happen", and even if it did, it would be ok.
+ *
+ * The routines calling guarantee_online_mems() are careful to
+ * only set nodes in task->mems_allowed that are online. So it
+ * should not be possible for the following code to return an
+ * offline node. But if it did, that would be ok, as this routine
+ * is not returning the node where the allocation must be, only
+ * the node where the search should start. The zonelist passed to
+ * __alloc_pages() will include all nodes. If the slab allocator
+ * is passed an offline node, it will fall back to the local node.
+ * See kmem_cache_alloc_node().
+ */
+
+int cpuset_mem_spread_node(void)
+{
+ int node;
+
+ node = next_node(current->cpuset_mem_spread_rotor, current->mems_allowed);
+ if (node == MAX_NUMNODES)
+ node = first_node(current->mems_allowed);
+ current->cpuset_mem_spread_rotor = node;
+ return node;
+}
+EXPORT_SYMBOL_GPL(cpuset_mem_spread_node);
+
+/**
* cpuset_excl_nodes_overlap - Do we overlap @p's mem_exclusive ancestors?
* @p: pointer to task_struct of some other task.
*