Incremental patch for missing kfree() at end. Will roll into next respin of the series. On Thu, 2009-07-30 at 12:15 +0100, Mel Gorman wrote: > On Wed, Jul 29, 2009 at 01:55:11PM -0400, Lee Schermerhorn wrote: > > [PATCH 3/4] hugetlb: derive huge pages nodes allowed from task mempolicy > > > > Against: 2.6.31-rc3-mmotm-090716-1432 > > atop the alloc_bootmem_huge_page() fix patch > > [http://marc.info/?l=linux-mm&m=124775468226290&w=4] > > > > V2: > > + cleaned up comments, removed some deemed unnecessary, > > add some suggested by review > > + removed check for !current in huge_mpol_nodes_allowed(). > > + added 'current->comm' to warning message in huge_mpol_nodes_allowed(). > > + added VM_BUG_ON() assertion in hugetlb.c next_node_allowed() to > > catch out of range node id. > > + add examples to patch description > > > > V3: Factored this patch from V2 patch 2/3 > > > > This patch derives a "nodes_allowed" node mask from the numa > > mempolicy of the task modifying the number of persistent huge > > pages to control the allocation, freeing and adjusting of surplus > > huge pages. This mask is derived as follows: > > > > * For "default" [NULL] task mempolicy, a NULL nodemask_t pointer > > is produced. This will cause the hugetlb subsystem to use > > node_online_map as the "nodes_allowed". This preserves the > > behavior before this patch. > > * For "preferred" mempolicy, including explicit local allocation, > > a nodemask with the single preferred node will be produced. > > "local" policy will NOT track any internode migrations of the > > task adjusting nr_hugepages. > > * For "bind" and "interleave" policy, the mempolicy's nodemask > > will be used. > > * Other than to inform the construction of the nodes_allowed node > > mask, the actual mempolicy mode is ignored. That is, all modes > > behave like interleave over the resulting nodes_allowed mask > > with no "fallback". > > > > Notes: > > > > 1) This patch introduces a subtle change in behavior: huge page > > allocation and freeing will be constrained by any mempolicy > > that the task adjusting the huge page pool inherits from its > > parent. This policy could come from a distant ancestor. The > > adminstrator adjusting the huge page pool without explicitly > > specifying a mempolicy via numactl might be surprised by this. > > Additionaly, any mempolicy specified by numactl will be > > constrained by the cpuset in which numactl is invoked. > > > > 2) Hugepages allocated at boot time use the node_online_map. > > An additional patch could implement a temporary boot time > > huge pages nodes_allowed command line parameter. > > > > 3) Using mempolicy to control persistent huge page allocation > > and freeing requires no change to hugeadm when invoking > > it via numactl, as shown in the examples below. However, > > hugeadm could be enhanced to take the allowed nodes as an > > argument and set its task mempolicy itself. This would allow > > it to detect and warn about any non-default mempolicy that it > > inherited from its parent, thus alleviating the issue described > > in Note 1 above. > > > > See the updated documentation [next patch] for more information > > about the implications of this patch. > > > > Examples: > > > > Starting with: > > > > Node 0 HugePages_Total: 0 > > Node 1 HugePages_Total: 0 > > Node 2 HugePages_Total: 0 > > Node 3 HugePages_Total: 0 > > > > Default behavior [with or without this patch] balances persistent > > hugepage allocation across nodes [with sufficient contiguous memory]: > > > > hugeadm --pool-pages-min=2048Kb:32 > > > > yields: > > > > Node 0 HugePages_Total: 8 > > Node 1 HugePages_Total: 8 > > Node 2 HugePages_Total: 8 > > Node 3 HugePages_Total: 8 > > > > Applying mempolicy--e.g., with numactl [using '-m' a.k.a. > > '--membind' because it allows multiple nodes to be specified > > and it's easy to type]--we can allocate huge pages on > > individual nodes or sets of nodes. So, starting from the > > condition above, with 8 huge pages per node: > > > > numactl -m 2 hugeadm --pool-pages-min=2048Kb:+8 > > > > yields: > > > > Node 0 HugePages_Total: 8 > > Node 1 HugePages_Total: 8 > > Node 2 HugePages_Total: 16 > > Node 3 HugePages_Total: 8 > > > > The incremental 8 huge pages were restricted to node 2 by the > > specified mempolicy. > > > > Similarly, we can use mempolicy to free persistent huge pages > > from specified nodes: > > > > numactl -m 0,1 hugeadm --pool-pages-min=2048Kb:-8 > > > > yields: > > > > Node 0 HugePages_Total: 4 > > Node 1 HugePages_Total: 4 > > Node 2 HugePages_Total: 16 > > Node 3 HugePages_Total: 8 > > > > The 8 huge pages freed were balanced over nodes 0 and 1. > > > > Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx> > > > > include/linux/mempolicy.h | 3 ++ > > mm/hugetlb.c | 13 ++++++--- > > mm/mempolicy.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 72 insertions(+), 5 deletions(-) > > > > Index: linux-2.6.31-rc3-mmotm-090716-1432/mm/mempolicy.c > > =================================================================== > > --- linux-2.6.31-rc3-mmotm-090716-1432.orig/mm/mempolicy.c 2009-07-28 11:15:10.000000000 -0400 > > +++ linux-2.6.31-rc3-mmotm-090716-1432/mm/mempolicy.c 2009-07-28 11:23:43.000000000 -0400 > > @@ -1544,6 +1544,67 @@ struct zonelist *huge_zonelist(struct vm > > } > > return zl; > > } > > + > > +/* > > + * huge_mpol_nodes_allowed -- mempolicy extension for huge pages. > > + * > > + * Returns a [pointer to a] nodelist based on the current task's mempolicy > > + * to constraing the allocation and freeing of persistent huge pages > > + * 'Preferred', 'local' and 'interleave' mempolicy will behave more like > > + * 'bind' policy in this context. An attempt to allocate a persistent huge > > + * page will never "fallback" to another node inside the buddy system > > + * allocator. > > + * > > + * If the task's mempolicy is "default" [NULL], just return NULL for > > + * default behavior. Otherwise, extract the policy nodemask for 'bind' > > + * or 'interleave' policy or construct a nodemask for 'preferred' or > > + * 'local' policy and return a pointer to a kmalloc()ed nodemask_t. > > + * > > + * N.B., it is the caller's responsibility to free a returned nodemask. > > + */ > > +nodemask_t *huge_mpol_nodes_allowed(void) > > +{ > > + nodemask_t *nodes_allowed = NULL; > > + struct mempolicy *mempolicy; > > + int nid; > > + > > + if (!current->mempolicy) > > + return NULL; > > + > > + mpol_get(current->mempolicy); > > + nodes_allowed = kmalloc(sizeof(*nodes_allowed), GFP_KERNEL); > > + if (!nodes_allowed) { > > + printk(KERN_WARNING "%s unable to allocate nodes allowed mask " > > + "for huge page allocation.\nFalling back to default.\n", > > + current->comm); > > + goto out; > > + } > > + nodes_clear(*nodes_allowed); > > + > > + mempolicy = current->mempolicy; > > + switch (mempolicy->mode) { > > + case MPOL_PREFERRED: > > + if (mempolicy->flags & MPOL_F_LOCAL) > > + nid = numa_node_id(); > > + else > > + nid = mempolicy->v.preferred_node; > > + node_set(nid, *nodes_allowed); > > + break; > > + > > + case MPOL_BIND: > > + /* Fall through */ > > + case MPOL_INTERLEAVE: > > + *nodes_allowed = mempolicy->v.nodes; > > + break; > > + > > + default: > > + BUG(); > > + } > > + > > +out: > > + mpol_put(current->mempolicy); > > + return nodes_allowed; > > +} > > #endif > > > > /* Allocate a page in interleaved policy. > > Index: linux-2.6.31-rc3-mmotm-090716-1432/include/linux/mempolicy.h > > =================================================================== > > --- linux-2.6.31-rc3-mmotm-090716-1432.orig/include/linux/mempolicy.h 2009-07-28 11:15:10.000000000 -0400 > > +++ linux-2.6.31-rc3-mmotm-090716-1432/include/linux/mempolicy.h 2009-07-28 11:23:43.000000000 -0400 > > @@ -201,6 +201,7 @@ extern void mpol_fix_fork_child_flag(str > > extern struct zonelist *huge_zonelist(struct vm_area_struct *vma, > > unsigned long addr, gfp_t gfp_flags, > > struct mempolicy **mpol, nodemask_t **nodemask); > > +extern nodemask_t *huge_mpol_nodes_allowed(void); > > extern unsigned slab_node(struct mempolicy *policy); > > > > extern enum zone_type policy_zone; > > @@ -328,6 +329,8 @@ static inline struct zonelist *huge_zone > > return node_zonelist(0, gfp_flags); > > } > > > > +static inline nodemask_t *huge_mpol_nodes_allowed(void) { return NULL; } > > + > > static inline int do_migrate_pages(struct mm_struct *mm, > > const nodemask_t *from_nodes, > > const nodemask_t *to_nodes, int flags) > > Index: linux-2.6.31-rc3-mmotm-090716-1432/mm/hugetlb.c > > =================================================================== > > --- linux-2.6.31-rc3-mmotm-090716-1432.orig/mm/hugetlb.c 2009-07-28 11:23:18.000000000 -0400 > > +++ linux-2.6.31-rc3-mmotm-090716-1432/mm/hugetlb.c 2009-07-28 11:24:43.000000000 -0400 > > @@ -1257,10 +1257,13 @@ static int adjust_pool_surplus(struct hs > > static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) > > { > > unsigned long min_count, ret; > > + nodemask_t *nodes_allowed; > > > > if (h->order >= MAX_ORDER) > > return h->max_huge_pages; > > > > + nodes_allowed = huge_mpol_nodes_allowed(); > > + > > /* > > * Increase the pool size > > * First take pages out of surplus state. Then make up the > > @@ -1274,7 +1277,7 @@ static unsigned long set_max_huge_pages( > > */ > > spin_lock(&hugetlb_lock); > > while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { > > - if (!adjust_pool_surplus(h, NULL, -1)) > > + if (!adjust_pool_surplus(h, nodes_allowed, -1)) > > break; > > } > > > > @@ -1285,7 +1288,7 @@ static unsigned long set_max_huge_pages( > > * and reducing the surplus. > > */ > > spin_unlock(&hugetlb_lock); > > - ret = alloc_fresh_huge_page(h, NULL); > > + ret = alloc_fresh_huge_page(h, nodes_allowed); > > spin_lock(&hugetlb_lock); > > if (!ret) > > goto out; > > @@ -1309,13 +1312,13 @@ static unsigned long set_max_huge_pages( > > */ > > min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; > > min_count = max(count, min_count); > > - try_to_free_low(h, min_count, NULL); > > + try_to_free_low(h, min_count, nodes_allowed); > > while (min_count < persistent_huge_pages(h)) { > > - if (!free_pool_huge_page(h, NULL, 0)) > > + if (!free_pool_huge_page(h, nodes_allowed, 0)) > > break; > > } > > while (count < persistent_huge_pages(h)) { > > - if (!adjust_pool_surplus(h, NULL, 1)) > > + if (!adjust_pool_surplus(h, nodes_allowed, 1)) > > break; > > } > > out: > > Where did the hunk go that calls kfree(nodes_allowed)? I think we might > be leaking in this version. > > Otherwise it looks good. > [PATCH] hugetlb: derive huge pages nodes allowed from task mempolicy FIX Against: 2.6.31-rc3-mmotm-090716-1432 with hugetlb: derive huge pages nodes allowed from task mempolicy restore kfree() of dynamically allocated nodes_allowed nodemask dropped during refactoring of patches. Caught by Mel Gorman. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx> --- mm/hugetlb.c | 1 + 1 file changed, 1 insertion(+) Index: linux-2.6.31-rc4-mmotm-090730-0501/mm/hugetlb.c =================================================================== --- linux-2.6.31-rc4-mmotm-090730-0501.orig/mm/hugetlb.c 2009-07-30 09:09:28.000000000 -0400 +++ linux-2.6.31-rc4-mmotm-090730-0501/mm/hugetlb.c 2009-07-30 09:11:07.000000000 -0400 @@ -1324,6 +1324,7 @@ static unsigned long set_max_huge_pages( out: ret = persistent_huge_pages(h); spin_unlock(&hugetlb_lock); + kfree(nodes_allowed); return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-numa" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
