diff options
| -rw-r--r-- | Documentation/cpusets.txt | 7 | ||||
| -rw-r--r-- | include/linux/cpuset.h | 2 | ||||
| -rw-r--r-- | kernel/cpuset.c | 56 |
3 files changed, 43 insertions, 22 deletions
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index f2c0a684293..b875d231ac7 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt @@ -35,7 +35,8 @@ CONTENTS: ---------------------- Cpusets provide a mechanism for assigning a set of CPUs and Memory -Nodes to a set of tasks. +Nodes to a set of tasks. In this document "Memory Node" refers to +an on-line node that contains memory. Cpusets constrain the CPU and Memory placement of tasks to only the resources within a tasks current cpuset. They form a nested @@ -220,8 +221,8 @@ and name space for cpusets, with a minimum of additional kernel code. The cpus and mems files in the root (top_cpuset) cpuset are read-only. The cpus file automatically tracks the value of cpu_online_map using a CPU hotplug notifier, and the mems file -automatically tracks the value of node_online_map using the -cpuset_track_online_nodes() hook. +automatically tracks the value of node_states[N_MEMORY]--i.e., +nodes with memory--using the cpuset_track_online_nodes() hook. 1.4 What are exclusive cpusets ? diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index 826b15e914e..9e633ea103c 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -93,7 +93,7 @@ static inline nodemask_t cpuset_mems_allowed(struct task_struct *p) return node_possible_map; } -#define cpuset_current_mems_allowed (node_online_map) +#define cpuset_current_mems_allowed (node_states[N_HIGH_MEMORY]) static inline void cpuset_init_current_mems_allowed(void) {} static inline void cpuset_update_task_memory_state(void) {} #define cpuset_nodes_subset_current_mems_allowed(nodes) (1) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 57e6448b171..8b2daac4de8 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -581,26 +581,28 @@ static void guarantee_online_cpus(const struct cpuset *cs, cpumask_t *pmask) /* * Return in *pmask the portion of a cpusets's mems_allowed that - * are online. If none are online, walk up the cpuset hierarchy - * until we find one that does have some online mems. If we get - * all the way to the top and still haven't found any online mems, - * return node_online_map. + * are online, with memory. If none are online with memory, walk + * up the cpuset hierarchy until we find one that does have some + * online mems. If we get all the way to the top and still haven't + * found any online mems, return node_states[N_HIGH_MEMORY]. * * One way or another, we guarantee to return some non-empty subset - * of node_online_map. + * of node_states[N_HIGH_MEMORY]. * * Call with callback_mutex held. */ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) { - while (cs && !nodes_intersects(cs->mems_allowed, node_online_map)) + while (cs && !nodes_intersects(cs->mems_allowed, + node_states[N_HIGH_MEMORY])) cs = cs->parent; if (cs) - nodes_and(*pmask, cs->mems_allowed, node_online_map); + nodes_and(*pmask, cs->mems_allowed, + node_states[N_HIGH_MEMORY]); else - *pmask = node_online_map; - BUG_ON(!nodes_intersects(*pmask, node_online_map)); + *pmask = node_states[N_HIGH_MEMORY]; + BUG_ON(!nodes_intersects(*pmask, node_states[N_HIGH_MEMORY])); } /** @@ -924,7 +926,10 @@ static int update_nodemask(struct cpuset *cs, char *buf) int fudge; int retval; - /* top_cpuset.mems_allowed tracks node_online_map; it's read-only */ + /* + * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY]; + * it's read-only + */ if (cs == &top_cpuset) return -EACCES; @@ -941,8 +946,21 @@ static int update_nodemask(struct cpuset *cs, char *buf) retval = nodelist_parse(buf, trialcs.mems_allowed); if (retval < 0) goto done; + if (!nodes_intersects(trialcs.mems_allowed, + node_states[N_HIGH_MEMORY])) { + /* + * error if only memoryless nodes specified. + */ + retval = -ENOSPC; + goto done; + } } - nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map); + /* + * Exclude memoryless nodes. We know that trialcs.mems_allowed + * contains at least one node with memory. + */ + nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, + node_states[N_HIGH_MEMORY]); oldmem = cs->mems_allowed; if (nodes_equal(oldmem, trialcs.mems_allowed)) { retval = 0; /* Too easy - nothing to do */ @@ -2098,8 +2116,9 @@ static void guarantee_online_cpus_mems_in_subtree(const struct cpuset *cur) /* * The cpus_allowed and mems_allowed nodemasks in the top_cpuset track - * cpu_online_map and node_online_map. Force the top cpuset to track - * whats online after any CPU or memory node hotplug or unplug event. + * cpu_online_map and node_states[N_HIGH_MEMORY]. Force the top cpuset to + * track what's online after any CPU or memory node hotplug or unplug + * event. * * To ensure that we don't remove a CPU or node from the top cpuset * that is currently in use by a child cpuset (which would violate @@ -2119,7 +2138,7 @@ static void common_cpu_mem_hotplug_unplug(void) guarantee_online_cpus_mems_in_subtree(&top_cpuset); top_cpuset.cpus_allowed = cpu_online_map; - top_cpuset.mems_allowed = node_online_map; + top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; mutex_unlock(&callback_mutex); mutex_unlock(&manage_mutex); @@ -2147,8 +2166,9 @@ static int cpuset_handle_cpuhp(struct notifier_block *nb, #ifdef CONFIG_MEMORY_HOTPLUG /* - * Keep top_cpuset.mems_allowed tracking node_online_map. - * Call this routine anytime after you change node_online_map. + * Keep top_cpuset.mems_allowed tracking node_states[N_HIGH_MEMORY]. + * Call this routine anytime after you change + * node_states[N_HIGH_MEMORY]. * See also the previous routine cpuset_handle_cpuhp(). */ @@ -2167,7 +2187,7 @@ void cpuset_track_online_nodes(void) void __init cpuset_init_smp(void) { top_cpuset.cpus_allowed = cpu_online_map; - top_cpuset.mems_allowed = node_online_map; + top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; hotcpu_notifier(cpuset_handle_cpuhp, 0); } @@ -2309,7 +2329,7 @@ void cpuset_init_current_mems_allowed(void) * * Description: Returns the nodemask_t mems_allowed of the cpuset * attached to the specified @tsk. Guaranteed to return some non-empty - * subset of node_online_map, even if this means going outside the + * subset of node_states[N_HIGH_MEMORY], even if this means going outside the * tasks cpuset. **/ |