From 786083667e0ced85ce17c4c0b6c57a9f47c5b9f2 Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Tue, 29 Apr 2008 01:00:26 -0700 Subject: Cpuset hardwall flag: add a mem_hardwall flag to cpusets This flag provides the hardwalling properties of mem_exclusive, without enforcing the exclusivity. Either mem_hardwall or mem_exclusive is sufficient to prevent GFP_KERNEL allocations from passing outside the cpuset's assigned nodes. Signed-off-by: Paul Menage Acked-by: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 48 ++++++++++++++++++++++++++++++++---------------- 1 file changed, 32 insertions(+), 16 deletions(-) (limited to 'kernel/cpuset.c') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index fe5407ca2f1..8da627d3380 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -127,6 +127,7 @@ struct cpuset_hotplug_scanner { typedef enum { CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE, + CS_MEM_HARDWALL, CS_MEMORY_MIGRATE, CS_SCHED_LOAD_BALANCE, CS_SPREAD_PAGE, @@ -144,6 +145,11 @@ static inline int is_mem_exclusive(const struct cpuset *cs) return test_bit(CS_MEM_EXCLUSIVE, &cs->flags); } +static inline int is_mem_hardwall(const struct cpuset *cs) +{ + return test_bit(CS_MEM_HARDWALL, &cs->flags); +} + static inline int is_sched_load_balance(const struct cpuset *cs) { return test_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); @@ -1042,12 +1048,9 @@ static int update_relax_domain_level(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_SCHED_LOAD_BALANCE, - * 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 + * bit: the bit to update (see cpuset_flagbits_t) + * cs: the cpuset to update + * turning_on: whether the flag is being set or cleared * * Call with cgroup_mutex held. */ @@ -1228,6 +1231,7 @@ typedef enum { FILE_MEMLIST, FILE_CPU_EXCLUSIVE, FILE_MEM_EXCLUSIVE, + FILE_MEM_HARDWALL, FILE_SCHED_LOAD_BALANCE, FILE_SCHED_RELAX_DOMAIN_LEVEL, FILE_MEMORY_PRESSURE_ENABLED, @@ -1313,6 +1317,9 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) case FILE_MEM_EXCLUSIVE: retval = update_flag(CS_MEM_EXCLUSIVE, cs, val); break; + case FILE_MEM_HARDWALL: + retval = update_flag(CS_MEM_HARDWALL, cs, val); + break; case FILE_SCHED_LOAD_BALANCE: retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, val); break; @@ -1423,6 +1430,8 @@ static u64 cpuset_read_u64(struct cgroup *cont, struct cftype *cft) return is_cpu_exclusive(cs); case FILE_MEM_EXCLUSIVE: return is_mem_exclusive(cs); + case FILE_MEM_HARDWALL: + return is_mem_hardwall(cs); case FILE_SCHED_LOAD_BALANCE: return is_sched_load_balance(cs); case FILE_MEMORY_MIGRATE: @@ -1474,6 +1483,13 @@ static struct cftype files[] = { .private = FILE_MEM_EXCLUSIVE, }, + { + .name = "mem_hardwall", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_MEM_HARDWALL, + }, + { .name = "sched_load_balance", .read_u64 = cpuset_read_u64, @@ -1963,14 +1979,14 @@ int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask) } /* - * nearest_exclusive_ancestor() - Returns the nearest mem_exclusive - * ancestor to the specified cpuset. Call holding callback_mutex. - * If no ancestor is mem_exclusive (an unusual configuration), then - * returns the root cpuset. + * nearest_hardwall_ancestor() - Returns the nearest mem_exclusive or + * mem_hardwall ancestor to the specified cpuset. Call holding + * callback_mutex. If no ancestor is mem_exclusive or mem_hardwall + * (an unusual configuration), then returns the root cpuset. */ -static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) +static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs) { - while (!is_mem_exclusive(cs) && cs->parent) + while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent) cs = cs->parent; return cs; } @@ -1984,7 +2000,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * __GFP_THISNODE is set, yes, we can always allocate. If zone * z's node is in our tasks mems_allowed, yes. If it's not a * __GFP_HARDWALL request and this zone's nodes is in the nearest - * mem_exclusive cpuset ancestor to this tasks cpuset, yes. + * hardwalled cpuset ancestor to this tasks cpuset, yes. * If the task has been OOM killed and has access to memory reserves * as specified by the TIF_MEMDIE flag, yes. * Otherwise, no. @@ -2007,7 +2023,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * and do not allow allocations outside the current tasks cpuset * unless the task has been OOM killed as is marked TIF_MEMDIE. * GFP_KERNEL allocations are not so marked, so can escape to the - * nearest enclosing mem_exclusive ancestor cpuset. + * nearest enclosing hardwalled ancestor cpuset. * * Scanning up parent cpusets requires callback_mutex. The * __alloc_pages() routine only calls here with __GFP_HARDWALL bit @@ -2030,7 +2046,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * in_interrupt - any node ok (current task context irrelevant) * GFP_ATOMIC - any node ok * TIF_MEMDIE - any node ok - * GFP_KERNEL - any node in enclosing mem_exclusive cpuset ok + * GFP_KERNEL - any node in enclosing hardwalled cpuset ok * GFP_USER - only nodes in current tasks mems allowed ok. * * Rule: @@ -2067,7 +2083,7 @@ int __cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask) mutex_lock(&callback_mutex); task_lock(current); - cs = nearest_exclusive_ancestor(task_cs(current)); + cs = nearest_hardwall_ancestor(task_cs(current)); task_unlock(current); allowed = node_isset(node, cs->mems_allowed); -- cgit v1.2.3