xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mempolicy: disallow static or relative flags for local preferred mode

Browse Source 
MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES don't mean anything for
MPOL_PREFERRED policies that were created with an empty nodemask (for purely
local allocations).  They'll never be invalidated because the allowed mems of
a task changes or need to be rebound relative to a cpuset's placement.

Also fixes a bug identified by Lee Schermerhorn that disallowed empty
nodemasks to be passed to MPOL_PREFERRED to specify local allocations.  [A
different, somewhat incomplete, patch already existed in 25-rc5-mm1.]

Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Rientjes
2008-04-28 02:12:34 -07:00
committed by Linus Torvalds
parent 3842b46de6
commit 3e1f064562
2 changed files with 40 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
mm/mempolicy.c
View File

@@ -181,27 +181,43 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
{
struct mempolicy *policy;
nodemask_t cpuset_context_nmask;
int localalloc = 0;
int ret;
pr_debug("setting mode %d flags %d nodes[0] %lx\n",
mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
if (mode == MPOL_DEFAULT)
return NULL;
if (!nodes || nodes_empty(*nodes)) {
if (mode != MPOL_PREFERRED)
if (mode == MPOL_DEFAULT) {
if (nodes && !nodes_empty(*nodes))
return ERR_PTR(-EINVAL);
localalloc = 1; /* special case: no mode flags */
return NULL;
}
VM_BUG_ON(!nodes);
/*
* MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
* MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
* All other modes require a valid pointer to a non-empty nodemask.
*/
if (mode == MPOL_PREFERRED) {
if (nodes_empty(*nodes)) {
if (((flags & MPOL_F_STATIC_NODES) ||
(flags & MPOL_F_RELATIVE_NODES)))
return ERR_PTR(-EINVAL);
nodes = NULL; /* flag local alloc */
}
} else if (nodes_empty(*nodes))
return ERR_PTR(-EINVAL);
policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
if (!policy)
return ERR_PTR(-ENOMEM);
atomic_set(&policy->refcnt, 1);
policy->policy = mode;
policy->flags = flags;
if (!localalloc) {
policy->flags = flags;
if (nodes) {
/*
* cpuset related setup doesn't apply to local allocation
*/
cpuset_update_task_memory_state();
if (flags & MPOL_F_RELATIVE_NODES)
mpol_relative_nodemask(&cpuset_context_nmask, nodes,
@@ -217,7 +233,7 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
}
ret = mpol_ops[mode].create(policy,
localalloc ? NULL : &cpuset_context_nmask);
nodes ? &cpuset_context_nmask : NULL);
if (ret < 0) {
kmem_cache_free(policy_cache, policy);
return ERR_PTR(ret);
@@ -259,10 +275,6 @@ static void mpol_rebind_preferred(struct mempolicy *pol,
{
nodemask_t tmp;
/*
* check 'STATIC_NODES first, as preferred_node == -1 may be
* a temporary, "fallback" state for this policy.
*/
if (pol->flags & MPOL_F_STATIC_NODES) {
int node = first_node(pol->w.user_nodemask);
@@ -270,12 +282,10 @@ static void mpol_rebind_preferred(struct mempolicy *pol,
pol->v.preferred_node = node;
else
pol->v.preferred_node = -1;
} else if (pol->v.preferred_node == -1) {
return; /* no remap required for explicit local alloc */
} else if (pol->flags & MPOL_F_RELATIVE_NODES) {
mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
pol->v.preferred_node = first_node(tmp);
} else {
} else if (pol->v.preferred_node != -1) {
pol->v.preferred_node = node_remap(pol->v.preferred_node,
pol->w.cpuset_mems_allowed,
*nodes);