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author | David Rientjes <rientjes@google.com> | 2008-04-28 02:12:30 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-28 08:58:19 -0700 |
commit | 4c50bc0116cf3cc35e7152d6a8424b4db65f52d6 (patch) | |
tree | 99c617602cc1946fc86b48e9a35f14f9f354cf67 | |
parent | 7ea931c9fc80c4d0a4306c30ec92eb0f1d922a0b (diff) | |
download | linux-stable-4c50bc0116cf3cc35e7152d6a8424b4db65f52d6.tar.gz linux-stable-4c50bc0116cf3cc35e7152d6a8424b4db65f52d6.tar.bz2 linux-stable-4c50bc0116cf3cc35e7152d6a8424b4db65f52d6.zip |
mempolicy: add MPOL_F_RELATIVE_NODES flag
Adds another optional mode flag, MPOL_F_RELATIVE_NODES, that specifies
nodemasks passed via set_mempolicy() or mbind() should be considered relative
to the current task's mems_allowed.
When the mempolicy is created, the passed nodemask is folded and mapped onto
the current task's mems_allowed. For example, consider a task using
set_mempolicy() to pass MPOL_INTERLEAVE | MPOL_F_RELATIVE_NODES with a
nodemask of 1-3. If current's mems_allowed is 4-7, the effected nodemask is
5-7 (the second, third, and fourth node of mems_allowed).
If the same task is attached to a cpuset, the mempolicy nodemask is rebound
each time the mems are changed. Some possible rebinds and results are:
mems result
1-3 1-3
1-7 2-4
1,5-6 1,5-6
1,5-7 5-7
Likewise, the zonelist built for MPOL_BIND acts on the set of zones assigned
to the resultant nodemask from the relative remap.
In the MPOL_PREFERRED case, the preferred node is remapped from the currently
effected nodemask to the relative nodemask.
This mempolicy mode flag was conceived of by Paul Jackson <pj@sgi.com>.
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>
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>
-rw-r--r-- | include/linux/mempolicy.h | 3 | ||||
-rw-r--r-- | mm/mempolicy.c | 33 | ||||
-rw-r--r-- | mm/shmem.c | 6 |
3 files changed, 39 insertions, 3 deletions
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index 07350d7b8d96..02b11efd7066 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -25,12 +25,13 @@ enum { /* Flags for set_mempolicy */ #define MPOL_F_STATIC_NODES (1 << 15) +#define MPOL_F_RELATIVE_NODES (1 << 14) /* * MPOL_MODE_FLAGS is the union of all possible optional mode flags passed to * either set_mempolicy() or mbind(). */ -#define MPOL_MODE_FLAGS (MPOL_F_STATIC_NODES) +#define MPOL_MODE_FLAGS (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES) /* Flags for get_mempolicy */ #define MPOL_F_NODE (1<<0) /* return next IL mode instead of node mask */ diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d59b1e766aee..ffd3be66b255 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -136,7 +136,15 @@ static int is_valid_nodemask(nodemask_t *nodemask) static inline int mpol_store_user_nodemask(const struct mempolicy *pol) { - return pol->flags & MPOL_F_STATIC_NODES; + return pol->flags & (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES); +} + +static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, + const nodemask_t *rel) +{ + nodemask_t tmp; + nodes_fold(tmp, *orig, nodes_weight(*rel)); + nodes_onto(*ret, tmp, *rel); } /* Create a new policy */ @@ -157,7 +165,12 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, return ERR_PTR(-ENOMEM); atomic_set(&policy->refcnt, 1); cpuset_update_task_memory_state(); - nodes_and(cpuset_context_nmask, *nodes, cpuset_current_mems_allowed); + if (flags & MPOL_F_RELATIVE_NODES) + mpol_relative_nodemask(&cpuset_context_nmask, nodes, + &cpuset_current_mems_allowed); + else + nodes_and(cpuset_context_nmask, *nodes, + cpuset_current_mems_allowed); switch (mode) { case MPOL_INTERLEAVE: if (nodes_empty(*nodes) || nodes_empty(cpuset_context_nmask)) @@ -873,6 +886,9 @@ asmlinkage long sys_mbind(unsigned long start, unsigned long len, mode &= ~MPOL_MODE_FLAGS; if (mode >= MPOL_MAX) return -EINVAL; + if ((mode_flags & MPOL_F_STATIC_NODES) && + (mode_flags & MPOL_F_RELATIVE_NODES)) + return -EINVAL; err = get_nodes(&nodes, nmask, maxnode); if (err) return err; @@ -891,6 +907,8 @@ asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask, mode &= ~MPOL_MODE_FLAGS; if ((unsigned int)mode >= MPOL_MAX) return -EINVAL; + if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) + return -EINVAL; err = get_nodes(&nodes, nmask, maxnode); if (err) return err; @@ -1745,10 +1763,12 @@ static void mpol_rebind_policy(struct mempolicy *pol, { nodemask_t tmp; int static_nodes; + int relative_nodes; if (!pol) return; static_nodes = pol->flags & MPOL_F_STATIC_NODES; + relative_nodes = pol->flags & MPOL_F_RELATIVE_NODES; if (!mpol_store_user_nodemask(pol) && nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) return; @@ -1761,6 +1781,9 @@ static void mpol_rebind_policy(struct mempolicy *pol, case MPOL_INTERLEAVE: if (static_nodes) nodes_and(tmp, pol->w.user_nodemask, *newmask); + else if (relative_nodes) + mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, + newmask); else { nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed, *newmask); @@ -1783,6 +1806,10 @@ static void mpol_rebind_policy(struct mempolicy *pol, pol->v.preferred_node = node; else pol->v.preferred_node = -1; + } else if (relative_nodes) { + mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, + newmask); + pol->v.preferred_node = first_node(tmp); } else { pol->v.preferred_node = node_remap(pol->v.preferred_node, pol->w.cpuset_mems_allowed, *newmask); @@ -1878,6 +1905,8 @@ static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) if (flags & MPOL_F_STATIC_NODES) p += sprintf(p, "%sstatic", need_bar++ ? "|" : ""); + if (flags & MPOL_F_RELATIVE_NODES) + p += sprintf(p, "%srelative", need_bar++ ? "|" : ""); } if (!nodes_empty(nodes)) { diff --git a/mm/shmem.c b/mm/shmem.c index 3e9fda0ca470..9435f298dd75 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1128,6 +1128,12 @@ static int shmem_parse_mpol(char *value, unsigned short *policy, if (flags) { if (!strcmp(flags, "static")) *mode_flags |= MPOL_F_STATIC_NODES; + if (!strcmp(flags, "relative")) + *mode_flags |= MPOL_F_RELATIVE_NODES; + + if ((*mode_flags & MPOL_F_STATIC_NODES) && + (*mode_flags & MPOL_F_RELATIVE_NODES)) + err = 1; } out: /* Restore string for error message */ |