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-rw-r--r--include/linux/nodemask.h28
-rw-r--r--mm/mempolicy.c84
2 files changed, 86 insertions, 26 deletions
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 829b94b156f2..b359c4a9ec9e 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -82,6 +82,12 @@
* to generate slightly worse code. So use a simple one-line #define
* for node_isset(), instead of wrapping an inline inside a macro, the
* way we do the other calls.
+ *
+ * NODEMASK_SCRATCH
+ * When doing above logical AND, OR, XOR, Remap operations the callers tend to
+ * need temporary nodemask_t's on the stack. But if NODES_SHIFT is large,
+ * nodemask_t's consume too much stack space. NODEMASK_SCRATCH is a helper
+ * for such situations. See below and CPUMASK_ALLOC also.
*/
#include <linux/kernel.h>
@@ -473,4 +479,26 @@ static inline int num_node_state(enum node_states state)
#define for_each_node(node) for_each_node_state(node, N_POSSIBLE)
#define for_each_online_node(node) for_each_node_state(node, N_ONLINE)
+/*
+ * For nodemask scrach area.(See CPUMASK_ALLOC() in cpumask.h)
+ */
+
+#if NODES_SHIFT > 8 /* nodemask_t > 64 bytes */
+#define NODEMASK_ALLOC(x, m) struct x *m = kmalloc(sizeof(*m), GFP_KERNEL)
+#define NODEMASK_FREE(m) kfree(m)
+#else
+#define NODEMASK_ALLOC(x, m) struct x _m, *m = &_m
+#define NODEMASK_FREE(m)
+#endif
+
+/* A example struture for using NODEMASK_ALLOC, used in mempolicy. */
+struct nodemask_scratch {
+ nodemask_t mask1;
+ nodemask_t mask2;
+};
+
+#define NODEMASK_SCRATCH(x) NODEMASK_ALLOC(nodemask_scratch, x)
+#define NODEMASK_SCRATCH_FREE(x) NODEMASK_FREE(x)
+
+
#endif /* __LINUX_NODEMASK_H */
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index e08e2c4da63a..7dd9d9f80694 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -191,25 +191,27 @@ static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
* Must be called holding task's alloc_lock to protect task's mems_allowed
* and mempolicy. May also be called holding the mmap_semaphore for write.
*/
-static int mpol_set_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
+static int mpol_set_nodemask(struct mempolicy *pol,
+ const nodemask_t *nodes, struct nodemask_scratch *nsc)
{
- nodemask_t cpuset_context_nmask;
int ret;
/* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
if (pol == NULL)
return 0;
+ /* Check N_HIGH_MEMORY */
+ nodes_and(nsc->mask1,
+ cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
VM_BUG_ON(!nodes);
if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
nodes = NULL; /* explicit local allocation */
else {
if (pol->flags & MPOL_F_RELATIVE_NODES)
- mpol_relative_nodemask(&cpuset_context_nmask, nodes,
- &cpuset_current_mems_allowed);
+ mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
else
- nodes_and(cpuset_context_nmask, *nodes,
- cpuset_current_mems_allowed);
+ nodes_and(nsc->mask2, *nodes, nsc->mask1);
+
if (mpol_store_user_nodemask(pol))
pol->w.user_nodemask = *nodes;
else
@@ -217,8 +219,10 @@ static int mpol_set_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
cpuset_current_mems_allowed;
}
- ret = mpol_ops[pol->mode].create(pol,
- nodes ? &cpuset_context_nmask : NULL);
+ if (nodes)
+ ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
+ else
+ ret = mpol_ops[pol->mode].create(pol, NULL);
return ret;
}
@@ -620,12 +624,17 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
{
struct mempolicy *new, *old;
struct mm_struct *mm = current->mm;
+ NODEMASK_SCRATCH(scratch);
int ret;
- new = mpol_new(mode, flags, nodes);
- if (IS_ERR(new))
- return PTR_ERR(new);
+ if (!scratch)
+ return -ENOMEM;
+ new = mpol_new(mode, flags, nodes);
+ if (IS_ERR(new)) {
+ ret = PTR_ERR(new);
+ goto out;
+ }
/*
* prevent changing our mempolicy while show_numa_maps()
* is using it.
@@ -635,13 +644,13 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
if (mm)
down_write(&mm->mmap_sem);
task_lock(current);
- ret = mpol_set_nodemask(new, nodes);
+ ret = mpol_set_nodemask(new, nodes, scratch);
if (ret) {
task_unlock(current);
if (mm)
up_write(&mm->mmap_sem);
mpol_put(new);
- return ret;
+ goto out;
}
old = current->mempolicy;
current->mempolicy = new;
@@ -654,7 +663,10 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
up_write(&mm->mmap_sem);
mpol_put(old);
- return 0;
+ ret = 0;
+out:
+ NODEMASK_SCRATCH_FREE(scratch);
+ return ret;
}
/*
@@ -1014,12 +1026,20 @@ static long do_mbind(unsigned long start, unsigned long len,
if (err)
return err;
}
- down_write(&mm->mmap_sem);
- task_lock(current);
- err = mpol_set_nodemask(new, nmask);
- task_unlock(current);
+ {
+ NODEMASK_SCRATCH(scratch);
+ if (scratch) {
+ down_write(&mm->mmap_sem);
+ task_lock(current);
+ err = mpol_set_nodemask(new, nmask, scratch);
+ task_unlock(current);
+ if (err)
+ up_write(&mm->mmap_sem);
+ } else
+ err = -ENOMEM;
+ NODEMASK_SCRATCH_FREE(scratch);
+ }
if (err) {
- up_write(&mm->mmap_sem);
mpol_put(new);
return err;
}
@@ -1891,6 +1911,7 @@ restart:
* Install non-NULL @mpol in inode's shared policy rb-tree.
* On entry, the current task has a reference on a non-NULL @mpol.
* This must be released on exit.
+ * This is called at get_inode() calls and we can use GFP_KERNEL.
*/
void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
{
@@ -1902,19 +1923,24 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
if (mpol) {
struct vm_area_struct pvma;
struct mempolicy *new;
+ NODEMASK_SCRATCH(scratch);
+ if (!scratch)
+ return;
/* contextualize the tmpfs mount point mempolicy */
new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
if (IS_ERR(new)) {
mpol_put(mpol); /* drop our ref on sb mpol */
+ NODEMASK_SCRATCH_FREE(scratch);
return; /* no valid nodemask intersection */
}
task_lock(current);
- ret = mpol_set_nodemask(new, &mpol->w.user_nodemask);
+ ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
task_unlock(current);
mpol_put(mpol); /* drop our ref on sb mpol */
if (ret) {
+ NODEMASK_SCRATCH_FREE(scratch);
mpol_put(new);
return;
}
@@ -1924,6 +1950,7 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
pvma.vm_end = TASK_SIZE; /* policy covers entire file */
mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
mpol_put(new); /* drop initial ref */
+ NODEMASK_SCRATCH_FREE(scratch);
}
}
@@ -2140,13 +2167,18 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
err = 1;
else {
int ret;
-
- task_lock(current);
- ret = mpol_set_nodemask(new, &nodes);
- task_unlock(current);
- if (ret)
+ NODEMASK_SCRATCH(scratch);
+ if (scratch) {
+ task_lock(current);
+ ret = mpol_set_nodemask(new, &nodes, scratch);
+ task_unlock(current);
+ } else
+ ret = -ENOMEM;
+ NODEMASK_SCRATCH_FREE(scratch);
+ if (ret) {
err = 1;
- else if (no_context) {
+ mpol_put(new);
+ } else if (no_context) {
/* save for contextualization */
new->w.user_nodemask = nodes;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 23:14:56 +0000